the Open Source hardware thread

Arduino

Alright, several TDF members are on their way to acquire their arduino boards from abroad. And I personally am trying to build one.

If any of you have experience with arduino, kindly share knowledge.

An arduino board can easily be purchased from ebay with pricing from ~500 and above. Arduino Uno boards cost ~1k and they are the current version for low end boards.

Click for Different types of Arduino boards.

Please note that, if you are starting new @ arduino, it is recommended to get a Diecimila / Duemilanove / Uno board. There previous two are outdated while Uno is the current standard. Apart from that, you can also acquire a Leonardo board, that has some spec advantages over Uno [Differences].

If you are familiar with electronics circuit making, you may try to build one for yourself :
(1) Arduino Single-Sided Serial Board.
(2) Diecimila. - This would be difficult to make though, you will have to solder a SMD IC FT232 on board, and will need to design the pcb layout yourself.

Things to remember when making / purchasing an Uno board:

The main microcontroller is either of ATmega8, ATmega168, ATmega328p. They have ~8KB,16KB,32KB of flash memory for porgram & bootloader storage.

If making a board, make sure to purchase the atmega micro controller chip that comes with bootloader preloaded (available in ebay), if not, then you will need an AVR programming device like USBAsp (available at ebay as well). Getting an USBAsp is good idea, so that u can later flash the bootloader of chip.
However, an arduino board can be flashed with another arduino board too, if you don't have the AVR programmer.

Diecimila / Duemilanove / Uno are all compatible design, so, these boards can be flashed with Uno bootloader if required.

I have not acquired the board yet, but those who have, please share ideas, guides and share some of your own projects thinking to undertake or already worked upon.

Do it yourself :

Arduino - Setting up an Arduino on a breadboard

u need to buy a pre bootloaded atmega8/168/328p microcontroller from ebay and also get the other components locally or online. (skip the bootloading process in the above link for a prebootloaded chip)

interfacing with computer can be done through the FT232L usb breakout board (available in ebay.in) or through serial port, via a MAX232 chip.

and voila! once u put all these together, u r ready to download C/C++ sketches into ur new arduino.

Re: Arduino projects & tutorials thread.

Thread for Arduino :doublethumb:

Some articles which I found useful:

Popular IC's often used with Arduino

Arduino - ShiftOut

Arduino Playground - 4051

Driving High Current Loads

G

Good ...

@quagmire thanks for the list. don't forget to post pics if u have already done some projects.

G

1.I suggest we rename thread to open source hardware thread and move to open source section.....wat to do you say guys?

might be apt to discuss arduino, beaglebone,rasberry pi etc open source hardware projects on single threads.

2.Heres a comparision of OSH boards for info
*atmelcorporation.files.wordpress.com/2013/04/comparison-arduino-uno-beaglebone-raspberry-pi.png

source

^If people decide to do that, please include "-Arduino/Rasp-Pi/BeagleBone" to thread title, so that people easily understand whats going on inside.

I agree with gopi_vbboy and icebags. +1 to 'Open source hardware'.

BTW I'm planning to buy a BeagleBone Black ( probably import for 45$ ) soon

G

icebags said:
^If people decide to do that, please include "-Arduino/Rasp-Pi/BeagleBone" to thread title, so that people easily understand whats going on inside.

sure as op ..you can pm any moderators (in green) to do that...its your call...i don't have permissions to do that

*learning-arduino.tumblr.com/

Nice initiative..

thanks for the link, but instead of posting ready made projects, why don't share some of your own projects thinking to undertake or already worked upon. *l.yimg.com/us.yimg.com/i/mesg/emoticons7/37.gif

that will be more interesting to see.

icebags said:
thanks for the link, but instead of posting ready made projects, why don't share some of your own projects thinking to undertake or already worked upon. *l.yimg.com/us.yimg.com/i/mesg/emoticons7/37.gif

that will be more interesting to see.

Yes, i too agree there.

Why not we post our own projects & details ??

Anyway eagerly waiting to try my hands on this. Meantime bought couple of things from local electronics store.

1). Soldering Station [Cheap one], liquid flux & Solder.

2). Few Resistors, Capacitors & Diodes.

3). Breadboard

4). Wire Stripper & Cutter

5). 16x2 lcd.

I hope by next weekend, i can post some crazy screenshot with my 8051 board & later with Ardruino

G

Some intresting tedx on OSH

1.

2.

^ its is amazing how ppl come up with those awesome ideas. just give them the tools to pley and they will make wonders.

G

Good intro

^ interesting. but where to find a beaglebone black at suitable price ? saw one @ ebay @4.5k but is that a proper price ? raspberry seems a bit cheaper.

realtime monitoring from pc is really a +point of beagle, what kind of web based programming platform u think is suitable for a black (it being the server and to be accessed from pc via lan) ? that can show the beagle port telemetry with numeric data as well as in graph format, while being lightweight.

d3p said:
Yes, i too agree there.

Why not we post our own projects & details ??

Anyway eagerly waiting to try my hands on this. Meantime bought couple of things from local electronics store.

1). Soldering Station [Cheap one], liquid flux & Solder.

2). Few Resistors, Capacitors & Diodes.

3). Breadboard

4). Wire Stripper & Cutter

5). 16x2 lcd.

I hope by next weekend, i can post some crazy screenshot with my 8051 board & later with Ardruino

hey ! what happened to pics u promised ?

Its okay as long as you don't have much content but once this thread begins to grow a separate sub-thread for each uC is a must.

I'll pick the Arduino. Needs only C++. Ready to use libraries. Excellent community support. Can even use AVR tools with Arduino as they all have the ATmega328. Though I worked on ATmega16.

^arduino is going to be popular because its cheap, easily obtainable, but dont know about others.
some members ordered arduino development boards from abroad and we are expecting to do some projects together, when they arrive.

meanwhile i received the atmega328 microprocessor from ebay @ ~320/-, that came with uno bootloader. going to set it up on a breadboard. also collected other components locally and prepared an usb cord for +5v supply. serial port interface is pending, & when it's done i will post.

if anyone more is interested, may check this link and post back any query in mind: Arduino - Setting up an Arduino on a breadboard

G

I have many doubts ppl ..sry asking due to high curiosity ..answer if u can help me..

In case of a embedded system lets say beagle-board or a custom board made from it using ARM-

1.How does linux know that a we use a particular processor and have connected peripherals in a particular way?
Say i have connected SDCARD controller to some pins.
How does linux know its at that particular pins ?
I means how are pins mapped to registers of particular peripherals?
It seems we need something called board support package like bios.Who gives this?Manufacturer?

If i compare with PC i get confused.In pc we have BIOS and we just use mass storage to boot linux and install.
PC motherboard are designed by vendor.But if i want to start with custom design of beagle, how to i add linux to it?

2.After some research, it appears that the a OS has to be ported to the board architecture which loads to RAM by bootloader.
Additionally we need to write device driver if any for custom peripherals.How do we write boot loader to a
custom board design rather than beagle board?How Device driver written or we optimize existing ones?

3.Is there any good book to understand these things about Linux+ARM os porting+ Device drivers+Hardware design?
I have good basics in EE and familiar working on pic microcontroller.So looking for resources.

Thanks in advance friends

^ supported linux comes with drivers for the beaglebone arm chip and architecture, there is no other way it would have worked.
^the attached sd card socket is already mapped for os loading purposes, it is the mass storage drive recognized by by the i/o chip interfacing bus.
^u can not attach sd card to any random input/output ports - be they analog or digital, if u attach, u will have to program it for those particular ports.

^if u want to write custom boot-loaders, u have to study the processor manual, write a c program i guess, initializing the processor registers, referencing the ram addresses etc, & then burn the hex code of the c program to the boot rom chip on board, by mean of a programmer board/hardware specific for that particular chip - this is true for arduino, i don't know about beagle, but they should be same.

^google & youtube are ur best book there.

gopi_vbboy said:
I have many doubts ppl

In case of a embedded system lets say beagle-board or a custom board made from it using ARM-

1.How does linux know that a we use a particular processor and have connected peripherals in a particular way?
Say i have connected SDCARD controller to some pins.
How does linux know its at that particular pins ?
I means how are pins mapped to registers of particular peripherals?
It seems we need something called board support package like bios.Who gives this?Manufacturer?

This is more of an OS related question. You'll need to study the Linux OS by some standard author to understand memory calls, interrupts... I'm not the best person to answer that.

Your bios in case of a microcontroller(uC) is the bootloader. It sits right inside the ROM memory(specific to the device so refer to the datasheet) and it can access any of inbuilt peripherals like USB, USART, CAN, SPI, etc. to exchange the data and this capability is used to write the flash memory. If it is not found then the program counter will point to the memory location 0000H(for example in ATmega16) and start executing the instructions which are written in the memory of the device.

gopi_vbboy said:
If i compare with PC i get confused.In pc we have BIOS and we just use mass storage to boot linux and install.
PC motherboard are designed by vendor.But if i want to start with custom design of beagle, how to i add linux to it?

The PC has a different architecture.

Again, OS centric question. You should ask in Beagleboard forums probably they have a better understanding of the platform. One of the members seems to have a similar query where he wants to replicate a design on his own. Though at this stage you won't understand much of it unless you have a working knowledge of Linux but still, just have a look.

Cloning Beaglebone

gopi_vbboy said:
2.After some research, it appears that the a OS has to be ported to the board architecture which loads to RAM by bootloader.
Additionally we need to write device driver if any for custom peripherals.How do we write boot loader to a
custom board design rather than beagle board?How Device driver written or we optimize existing ones?

There is no need to write a bootloader to a custom design or even the manufacturer shipped official Beagleboard. You should be more concerned with burning the bootloader than making it, though you can provided you know the Linux Kernel thoroughly. Making a bootloader is more of a specialist subject so publicly you won't find a standard text. You'll have to dig.

gopi_vbboy said:
3.Is there any good book to understand these things about Linux+ARM os porting+ Device drivers+Hardware design?
I have good basics in EE and familiar working on pic microcontroller.So looking for resources.

Thanks in advance friends

I have books on the subjects but forgot to bookmark them

I will however mention the standard references so you know what to look for however, you'll need to hunt for illegal sources as they are prohibited from posting here on this forum :twisted:

This should be the ideal starting point
Operating Systems : Internals and Design Principles 6 Edition

Step 2
Linux Kernel Development

A great free book

Linux Kernel in a Nutshell

Step 3: This is where you are on your own now
Writing device drivers in Linux: A brief tutorial

Don't get turned off by the funny title, the author is a post graduate in CS from IISC

Device Drivers, Part 1: Linux Device Drivers for Your Girl Friend

ARM is a different story, but Linux still applies

Start, here
The Definitive Guide to the ARM Cortex-M3
(Probably the most popular text)

Then this
ARM System-on-Chip Architecture

I have both books with me but those links are now probably taken down. I had used blackhat methods to get them :twisted:

so if you need it badly then I'll upload it to some file host for you to download but the first book on ARM is easily available. The second one will be, if you google hard enough.

Now, I hope you have something to read this weekend

icebags said:
^google & youtube are ur best book there.

The simplest and most effective answer. Even beats my own :-x

^ this is why i say start with the simplest. first get to know the simple ones, try with atmega. the programming manual is probably ~600 pages i heard (u dont everything, and neither u need to remember everything

) but u can still manage ur custom bootloader c program quite easily. i am looking forward to this as well, in very near future.

chip level programming those arm or higher end processors has to be quite a task to anybody. :-x

Looks good people Looks Good.

Code:

*makezine.com/category/electronics/raspberry-pi/

icebags said:
chip level programming...

Chip level programming is basically treading into microelectronics territory so its all Verilog and VHDL

icebags said:
...those arm or higher end processors has to be quite a task to anybody.

Nah...many boards are based off ARM like your very own Beagleboard and Raspberry Pie. So, you indirectly work with ARM chips anyway.

If someone wants to just get inside this territory then this makes for a good noob friendly intro
ARM Basics
(Though you don't need it if you've already read the books mentioned, but still)

This document is a true hands-on introduction which one should read
ARM Cross Development with Eclipse

The Philips LPCxxx series is the most common way to get into ARM development. But what you are implying is the professional line of work. Even professionals work with the same devices albeit with a different objective and a lot more powerful set of tools. So, its not that high end of a device that we cannot mess with.

AFAIK its the DSP processors that are supposed to be for the academically inclined and not fit for general public consumption :-D

Now that would be serious task :twisted:

G

@Mr.Kickass Thanks a lot...will read and research

@icebags Thanks man..

@Mr.Kickass thanks, very informative.

So, I stayed up yesterday and somehow managed to get hold of an officially ~~illegal~~ legal source of the book which every newcomer should at least read once before starting out. The only con to this book is that it adopts Assembly and C as the language of instruction so those looking for coding in C++ using the Arduino IDE should simply skip it. The datasheet has all the relevant information about the controller.

I think the Arduino website is enough for getting started. Only those who wish to develop using tools provided by Atmel itself should bother reading the book. But this should be kept in mind that even the datasheet is biased towards using AVR suite which uses C (of course marketing, and why not)

This should be the starting point for anyone. Why ? Because this is what powers the Arduino Uno.
ATmega48A/PA/88A/PA/168A/PA/328/P Complete

You do not even need to read all of it(as not all of the features are required in building a system) but just complement it with a standard text like this
AVR Microcontroller and Embedded Systems.pdf

I hope the mods don't delete this link :Fingerx:

For those going the Arduino way, be sure to learn C++ very well and those going the AVR route should take the concept of bit manipulation seriously because programming in Arduino IDE is very very easy. You have a function for everything. There is a HUGE library at your disposal. Which is why its best for a newbie to start with that. Of course, it has its pitfall too. You cannot have low level control of hardware as you can have in AVR. But, in AVR you need to write a sub-routine even to take an input. In Arduino IDE its as easy as writing cin>> in C++

arrived my atmega328p with uno bootloader preloaded, from ebay (rs.~350/-). i connected it on a breadboad and led on pin 19 (pin 13 of a uno board) started blinking, seems they uploaded the blinky sketch on it too.

i am unable to upload a sketch myself, tried to interface it with com port via a max232 chip, but it could not communicate. multimeter shows when board is active usb voltage drops to ~4.25v, normally which i measured remains @ ~4.55v without load. max232 works @5v or may be 4.5v minimum, probably this is why. or may be my com port cable is too long. i need to see with a proper 5v source.

*i.imgur.com/HPjIpeb.jpg

also bought 2 blank atmega8s locally @ 65 -80rs. will try to upload stuff later onto them

*i.imgur.com/m1HX0U1.jpg

Anyone here have Raspberry Pi?

^*www.thinkdigit.com/forum/show-off/177167-my-raspberrypi.html
A quick search in the 'Post your latest Purchase' thread reveals d6bmg and nginx own a RasPi.

@icebags: Good to know people in TDF are into AVR development.

I bought an Atmega32 (40pin) for 190/- from SP Road, Bangalore.. Why did you pay so much for Atmega328?

Since you have a Atmega8 you can take a look at this : USBASP. Programmer for AVR uC..

I made the same a few days ago. Both on a perfboard and PCB :wink:

. Works perfectly fine. (Better than max232 types..)

G

hi to @Kickass, @Icebags, @Quagmire and all

Started reading operating systems by william stalling..intresting till now.

Planning to buy beglebone or pi soon

--

I did quite research on beagleboard TI AM335x Datasheets and Uboot source code.

Have a few questions on beagleboard

1.Is Uboot/Any bootloader the only thing used to initialize the hardware in board?
Can we initialize hardware later in kernel space from linux?
Do we have to initialize them again from user space though drivers written inorder to use them?

2.I am just confused how hardware pins maps to registers and peripherals are initialized?
Are they done in user space or driver or bootloader?
When i compare with microcontroller i get confused.In microcntroller we only have a C language
code with infinite while(1){} loop.Before that Oscillators ,Ports ,peripherals are initialized.
Howz that done by Beagleboard and at what stage?

3.How does processor know that our Uboot binary is at particular SPI flash?
I mean how is the processor configured/initialized before loading boot-loader to ram i.e the moment we power on?

4.Why do we have some co processor in beaglebone?Is it to program the SPI flash though Serial/USB?

5.Is linux a generic kind of layer of code?I mean does it try to minimize board specific code like hardware initializations etc?

icebags said:
^ interesting. but where to find a beaglebone black at suitable price ? saw one @ ebay @4.5k but is that a proper price ? raspberry seems a bit cheaper.

Is this of any help ?

Besides, I'd prefer the BeagleBone

BeagleBone Black: A Maker’s Dream?

quagmire said:
I bought an Atmega32 (40pin) for 190/- from SP Road, Bangalore.. Why did you pay so much for Atmega328?
Since you have a Atmega8 you can take a look at this : USBASP. Programmer for AVR uC..
I made the same a few days ago. Both on a perfboard and PCB . Works perfectly fine. (Better than max232 types..)

i asked local shops for 328, they were saying ~300, so just thought of buying one with bootloader at some extra price, to escape the process of bootloading for the first time.

saw that usbasp link too, did not read details yet, but i would like to ask, how u loaded the usbasp firmware onto that atmega8 ? having an usbasp is a good idea, i read it can program sketches directly to chips, saving the bootloader space - good for standalone projects with atmega8s.

i am trying to use max232 for direct serial interfacing, for realtime arduino access, is it possible with usbasp ?

Mr.Kickass said:
Is this of any help ?

Besides, I'd prefer the BeagleBone

BeagleBone Black: A Maker’s Dream?

thinking of making a query to borderless electronics if they are enthuciastic about launching a similar campain for beaglebone like they did with arduino. anyways, i will play with arduino for a while now.

gopi_vbboy said:
Started reading operating systems by william stalling..intresting till now.

Planning to buy beglebone or pi soon

i have 0 beaglebone specific knowledge, only saw a few codes where they were using shell scripts to read/write data to pins, it appeared kinda similar to file programming to me. may be kickass will be able to help.

but this will probably be a good watch for u.

icebags said:
i asked local shops for 328, they were saying ~300, so just thought of buying one with bootloader at some extra price, to escape the process of bootloading for the first time.

saw that usbasp link too, did not read details yet, but i would like to ask, how u loaded the usbasp firmware onto that atmega8 ? having an usbasp is a good idea, i read it can program sketches directly to chips, saving the bootloader space - good for standalone projects with atmega8s.
i am trying to use max232 for direct serial interfacing, for realtime arduino access, is it possible with usbasp ?

thinking of making a query to borderless electronics if they are enthuciastic about launching a similar campain for beaglebone like they did with arduino. anyways, i will play with arduino for a while now.

1.I have an Arduino Uno. I used it as a ISP (alongwith avrdude) and uploaded the firmware from the website.
2. Yes, you can simply connect MISO, MOSI, SCLK, VCC, GND from USBasp to target board and upload the hex file.
3. I am not sure. Also a disadvantage is that it is not supported by Atmel Studio, which gives you great tools for debugging..
4. Exactly. I'm dying to get my hands on a BeagleBone, but here the price from a authorised distributor is 4k :-(

quagmire said:
4. Exactly. I'm dying to get my hands on a BeagleBone, but here the price from a authorised distributor is 4k

Get the new BeagleBone Black. It's cheaper than the 4K one

gopi_vbboy said:
hi to @Kickass, @Icebags, @Quagmire and all

Started reading operating systems by william stalling..intresting till now.

Yep. That's the standard text. The very foundation

gopi_vbboy said:
Have a few questions on beagleboard

^Beagleboard experts please...

IMO, you can ask in their forums as I'm sure they must be having an answer to that. And I'm yet to get a Beaglebone Black

G

ok

^yes, please enlighten us with the overseas forum knowledge once in a while here.

G

Hey guys just a query..45$ Beaglebone black is Rs 4490. .Do you think its a good deal? .. Is this imported or local manufactured?
BeagleBone Black. A Competitor to Raspberry Pi | eBay

Tech

Make ur choices
BeagleBone Black vs. Raspberry Pi - Roboteurs
*makezine.com/magazine/how-to-choose-the-right-platform-raspberry-pi-or-beaglebone-black/

S

few months back BeagleBone Black was 3.5k in element14.
now with 4.5k this sucks for amateur like me.

What are the chances of damaging the board (Pi and Arduino) if I do the circuit wrong? Asking this, as I'm a newbie to electronics and if I mistakenly do anything wrong and power it up.

krishnandu.sarkar said:
What are the chances of damaging the board (Pi and Arduino) if I do the circuit wrong? Asking this, as I'm a newbie to electronics and if I mistakenly do anything wrong and power it up.

When i connect my components doing electronics projects, i end up burning IC's. So I suggest you to read the link and use the fix befoer doing anything wrong
10 Ways to Destroy an Arduino : Application Note ANCP01

PS: I even burnt a solar panel [small one for a project] when trying to charge a battery, from then i came to know why exactly Diode is used

amjath said:
When i connect my components doing electronics projects, i end up burning IC's. So I suggest you to read the link and use the fix befoer doing anything wrong
10 Ways to Destroy an Arduino : Application Note ANCP01

PS: I even burnt a solar panel [small one for a project] when trying to charge a battery, from then i came to know why exactly Diode is used

Thanks a lot

I thought I read, somewhere, that Arduino and Pi is built like that way, if I do anything wrong, current won't pass backwards. I guess it was wrong.

last day i was also going through some video tutorials and noticed too much electronics things going on and wonder the same thing what are the chances that it will give me electric shock? if i messed up anything the whole board will go kaput :lol:

but then i also watched their documentry on how they got started and everything and it seems that its build that way that beginners can hardly blew it up if they mess up while doing something.

just 1 thing that do not connect usb cable while your doing programming when you done connect the cable and run your codes.

^get a main cord and put the wire ends into pi holes. make the switch on and see if it blows up or not ?

(for personal security, please don't forget to wear safety goggles and position urself atleast 10mts away while trying the above experiment with ur favourite pi board.)

Arduino | Projects, Tutorials, Videos and more Video - element14
Tutorial Series for Arduino - YouTube
Video: Tutorial 01 for Arduino: Getting Acquainted with Arduino - element14

S

My 7 segment display from 0 to 9 using stm32 discovery.

pic not showing, share it via image hosting site ?

S

^ Here
Picture is little dark.

*i.imgur.com/XgRN3cX.jpg

^good. so, it does count from 0 to 9 ?

and educate us a bit about stm32 board, how to use it and where to get it from ?

Oh man this is great news

Arduino Announces new Boards and Collaboration with Intel and T.I.
*makezineblog.files.wordpress.com/2013/10/galileo.jpg?w=620&h=466
A sneak preview of Arduino TRE powered by Texas Instruments
*makezineblog.files.wordpress.com/2013/10/2.jpg?w=620&h=413

One cannot even begin to imagine the magnitude of awe and amusement that is caused by this kind of collaboration. Back in the day it was really impossible to learn about x86 without going through a few hoops because the hardware just wasn't available. The only x86 machine popular was the Windows machine(practically every PC) but the problem was that develompent wasn't as slick as Arduino or Beaglebone.

But this is.... just wow. An excellent platform for anyone interested in learning to code an x86(the Intel Galileo) or an ARM based machine(Arduino TRE)

Now this goes without saying, I never ever ever, put a random link off the web. So these are the standard forums where you get highly detailed answers to even simple questions. Now, digit people are the best guys around so everybody knows AnandTech but for the uninformed there is this electronics hobbyist site called adafruit created by a person known by the pseudonym Ladyada having quite a history. The company is known as the Adafruit industries. So, the links...

Intel Announces Galileo: Quark Based Arduino Compatible Developer Board
(Sorry for the jargon heavy post but that is AnandTech for you :))

)

BREAKING NEWS – There is now an Intel based Arduino – Galileo
(News from Adafruit)

Wow..!! That's really great

I must learn basics as fast as possible. Hope I can utilize the festive season holiday coming

krishnandu.sarkar said:
Wow..!! That's really great

I must learn basics as fast as possible. Hope I can utilize the festive season holiday coming

This => Tutorial 14 for Arduino: Holiday Lights and Sounds Spectacular! - YouTube

^ arduino holiday guide, lol.

Thanks a lot

I'll surely go through those series and the ones posted above on this holiday

Any specific site you would like to recommend for learning electronics basics? Though I'm doing that by googling around, managed to learn how breadboard is designed internally, which helped me understand how can I connect components and all. Need to know more and more

Came to know basic things of basic components like Resistors, Capacitors, Diode and all

You see, I'm still struggling on basic electronics as I'm not from that background

^ that guy has covered some of the basic electronics which you will need to understand his tutorials.

IF i get my diwali bonus early then i will build that thing for sure.

@all
Buy BeagleBone Black from here - *tenettech.com/product/2912/beaglebone-black (not available at the moment)

^^ this site is good.

gopi_vbboy said:
1.Is Uboot/Any bootloader the only thing used to initialize the hardware in board?
Can we initialize hardware later in kernel space from linux?
Do we have to initialize them again from user space though drivers written inorder to use them?

U-Boot's job is simply that of a desktop computer bootloader. Load an operating system.

Beaglebone, Raspberry Pi, Pandaboard etc are essentially computers. A secondary media needs to have an operating system.

You use a SD Card flash an operating system on it. U-Boot's job is to boot that. Get the kernel running in the memory, mount devices as filesystems etc.

gopi_vbboy said:
2.I am just confused how hardware pins maps to registers and peripherals are initialized?
Are they done in user space or driver or bootloader?
When i compare with microcontroller i get confused.In microcntroller we only have a C language
code with infinite while(1){} loop.Before that Oscillators ,Ports ,peripherals are initialized.
Howz that done by Beagleboard and at what stage?

In Linux, you can mess around with the hardware by editing simple text files.

The /sys folder in the filesystem contains these files. So, you can use a program in any language like Python, C etc to edit the content of those files and do the desired task.

gopi_vbboy said:
3.How does processor know that our Uboot binary is at particular SPI flash?
I mean how is the processor configured/initialized before loading boot-loader to ram i.e the moment we power on?

Embedded Linux platforms like Beaglebone, Raspberry Pi etc are NOT microcontrollers. They are like your normal desktop computers.

You're confusing them with something like Arduino. The 'bootloader' when we talk about Arduino is different and works differently. U-boot is more like the bootloader you see on desktop computers.

In embedded Linux platforms, everything will happen after the operating system boots. Just like it is with your computer.

gopi_vbboy said:
4.Why do we have some co processor in beaglebone?Is it to program the SPI flash though Serial/USB?

This will tell you more - BeagleBone Black: BBB - Working with the PRU-ICSS/PRUSSv2 - element14

krishnandu.sarkar said:
Any specific site you would like to recommend for learning electronics basics? Though I'm doing that by googling around, managed to learn how breadboard is designed internally, which helped me understand how can I connect components and all. Need to know more and more

Came to know basic things of basic components like Resistors, Capacitors, Diode and all

You see, I'm still struggling on basic electronics as I'm not from that background

Oh c'mon, I already wrote such a huge post pointing you to the resources(with the links). We even had a conversation in this thread and you forgot all about that ? I'll re-post all that minus the description.

All About Circuits
Basic Electronics Tutorials
edaboard(Not a tutorial but a forum where you can always ask for help when buidling a circuit and btw they really DO help)

Now, this has got NOTHING to do with your query but this is so awesome that I just couldn't help but mention it anyway :-D

letsmakerobots(If you want to make a robot then you should definitely visit this)

Finally, the obvious...

Jeremy Blum's Arduino Tutorial(Both TheHumanBot and quagmire mentioned it sometime ago)

EDIT: Now that you've learnt about breadboards its about time you started building some simple circuits to get a hang of it so that you can move on to the next level

krishnandu.sarkar said:
You see, I'm still struggling on basic electronics as I'm not from that background

go for kickass no.1 link : Volume I - DC : All About Circuits

its as basic as possible.

Thanks a lot to both of you

No Mr.Kickass I didn't forget the discussions. But it's just the thing that after returning from office I don't get much time

But now I'm determined, I'll do something. Thanks a lot again for all your help

krishnandu.sarkar said:
No Mr.Kickass I didn't forget the discussions. But it's just the thing that after returning from office I don't get much time

But now I'm determined, I'll do something. Thanks a lot again for all your help

Nah...its alright. I'm surprised that you can even save time for visiting this thread

I know you'll catch up pretty quickly

This was one of the channels I'd use to browse frequently as a refresher for basics. Just watch one video and see if it helps.

Electronics 101

Electronics 201

G

krishnandu.sarkar said:
Thanks a lot I'll surely go through those series and the ones posted above on this holiday

Any specific site you would like to recommend for learning electronics basics? Though I'm doing that by googling around, managed to learn how breadboard is designed internally, which helped me understand how can I connect components and all. Need to know more and more

Came to know basic things of basic components like Resistors, Capacitors, Diode and all

You see, I'm still struggling on basic electronics as I'm not from that background

1.
Haha thats nice excuse.. :-D

...If you have the interest..you can learn..as simple as that....Its like saying i cant do Linux as i am from ...lol

2.
Thanks ico for answers

3.@Kickass

Is that intel galileo a x86 microcontroller or microprocessor?Can it run a OS?

gopi_vbboy said:
3.@Kickass

Is that intel galileo a x86 microcontroller or microprocessor?Can it run a OS?

I didn't get into details but you can help yourself here,
Intel® Galileo Support Page

This is the datasheet, I haven't read it yet
Galileo Datasheet

gopi_vbboy said:
1.
Haha thats nice excuse.. ...If you have the interest..you can learn..as simple as that....Its like saying i cant do Linux as i am from ...lol

It's not a excuse..!! Anyway, That's right. I agree. If one really have interest, he/she will ofcourse learn, it may take time according to his/her ability or intelligence, but eventually he/she will make it

Till now, I did everything what I know today by following the same theory

Members of #krow knows that

Specially ico and LFC_Fan

Hey guys, gone through the Video #2 posted by Mr. Kickass and others, but I'm unable to understand how the current is flowing, the logic actually.

Ok, so here's what I got.

1. He connects +5V with a wire to one side of switch.
2. And another side of switch is pulled to ground via a resistor. Why? Resistor is used to control the flow of a current, here it's used so that LED doesn't blows off if it get's more voltage. Right? So why it's connected to ground? Which will complete the circuit?
3. Now another line from one side of resistor is connected to Arduino port A, and a LED is connected on Pin 13 and GND respectively.

So what's the flow of a current when switch is pressed and when not pressed? I want to know the logical flow.

I'd be glad if someone can explain with a diagram in paint

Ok, I think I got the logic. I'll explain it here, please correct me if I'm wrong.

1. Current flows from Arduino +5V to Breadboard +5V Rail, which is connected to a end of push button.
2. Now if the button is not pressed, everything stops here. But if the button is pressed, the circuit begins, i.e. the flow begins to the other end of the switch.
3. Now the other end is connected to the GND via a resistor, which ensures, if more current comes in, it'll be grounded

4. Proper current pass through the circuit to the PIN A of Arduino, where a LED is connected to PIN 13 and GND, and the current flows internally within Arduino circuit.

Am I right?

which video u talk about ?
anyways, even though a battery is often shown with + and - polarities, mostly - is taken as ground. i.e. neutral.

mostly the circuits are build with +ve and gnd terminals, where current flows from + to gnd. but sometimes -ve polarities are required and in this case current flows from gnd to -ve.

if u see any power source, dont try to connect its terminals directly, cause this will result in maximum current flow- i.e. overload / short. because the heat generation is proportional to square(current flow) burnout/ explosion will occur.

so, even when working with a small pencil battery, try to make the circuit at least of 100 ohms on per cell basis. this will result in
1.5/100 = 15mA current, that is a power dissipation capability of 0.015x1.5 = 22.5 mW which is quite safe for short duration.

when u buy resistances at shops, they are available at different watt capabilities, 1/4W, 1/2W, 1W, 2W ...... ->
for most small voltage circuits with good resistance, 1/4W or 1/2W will suffice.

icebags said:
which video u talk about ?
anyways, even though a battery is often shown with + and - polarities, mostly - is taken as ground. i.e. neutral.

mostly the circuits are build with +ve and gnd terminals, where current flows from + to gnd. but sometimes -ve polarities are required and in this case current flows from gnd to -ve.

if u see any power source, dont try to connect its terminals directly, cause this will result in maximum current flow- i.e. overload / short. because the heat generation is proportional to square(current flow) burnout/ explosion will occur.

so, even when working with a small pencil battery, try to make the circuit at least of 100 ohms on per cell basis. this will result in
1.5/100 = 15mA current, that is a power dissipation capability of 0.015x1.5 = 22.5 mW which is quite safe for short duration.

when u buy resistances at shops, they are available at different watt capabilities, 1/4W, 1/2W, 1W, 2W ...... ->
for most small voltage circuits with good resistance, 1/4W or 1/2W will suffice.

Thanks

No, I was not asking about whether electricity flows from +ve => GND or anything. That I googled about then

I was asking the flow logic of

krishnandu.sarkar said:
...it may take time according to his/her ability or intelligence, but eventually he/she will make it

Neuroplasticity actually backs the 10,000 hour Rule, so no matter how poorly it may be written and disputed by some reports you WILL eventually make it

krishnandu.sarkar said:
Am I right?

Yes and while you're at it you can go through this video but just skim through it, however I'd suggest you take it slow and don't miss any important bits from the preceding videos

Sure @Mr. Kickass, thanks a lot

You and others are helping me from the beginning

I'll keep going through the videos that are posted by you and others and also I'm reading the links you provided

I'll post again if I get stuck somewhere or face problems understating anything

krishnandu.sarkar said:
I'd be glad if someone can explain with a diagram in paint

Apparently, the official Blink tutorial works without a switch so they look something like this

*arduino.cc/en/uploads/Tutorial/ExampleCircuit_sch.png

And the actual circuit is this

*arduino.cc/en/uploads/Tutorial/ExampleCircuit_bb.png

But Jeremy puts a switch in between and you have got it right there. So it now should look something like this

*i.imgur.com/94lQ68Wl.jpg
I made this in a hurry but you can see that the other end of the switch goes to pin 8 of Arduino(but the wire that connects the LED to the ground does NOT connects with this wire. I really couldn't label it as there seems to be some limitation with this software).This is what drives the switchPin and sends an ON and OFF. You already are a programmer so I guess you don't need that.

It goes Arduino>switch>LED.

The LED pin is triggered internally according to the sketch you uploaded

BeagleBoard.org collaborates in creation of new Arduino TRE
*beagleboard.org/static/images/tre/IMG_1242_smaller.jpg
*beagleboard.org/static/images/tre/IMG_1244_smaller.jpg

*i.imgur.com/H8g342ql.jpg

Thanks a lot Mr. Kickass for the schematic diagram

Somebody dig this

DragonBoard™ Development Kit

^

500$ for Snapdragon 800 Series APQ8074 based kit..

I'd rather buy a Kindle Fire HDX (229$ one) and rip the processor from there.. :lol:

You can always have workarounds

A wire lead got broken and stuck in to GND Port of Arduino

Tried to take it out with a needle, but it's not working. Do you think if I put faviquick on a end of a wire and keep it there for sometime and then pull it out it'll work?

Though it's not a big problem, as I can put other wires there, but with little difficulty, not as smooth as other ports.

Tried googling, and saw that it's a common problem.

*www.complete-healthcare.co.uk/images/inst4.jpg

icebags said:
*www.complete-healthcare.co.uk/images/inst4.jpg

I have this, but it's not working. The holes are too tiny for this.

u can try simple easy ways, if it doesn't come out, i guess u will have to live with that.

optionally, go to some electronic parts store and buy single strip female berg header, and ask a local radio / tv repair shop to gently replace the board berg header with it.

*www.electroncomponents.com/image/cache/data/misc/connector/EC_female_breakout-500x500.jpg

icebags said:
u can try simple easy ways, if it doesn't come out, i guess u will have to live with that.

optionally, go to some electronic parts store and buy single strip female berg header, and ask a local radio / tv repair shop to gently replace the board berg header with it.

*www.electroncomponents.com/image/cache/data/misc/connector/EC_female_breakout-500x500.jpg

Thanks. Yeah I'm living with it for now

Later if required dad can do that for me

There's no need of local Electronics shop for these things in my home

Almost 80% of my family members is into electronics (electrical actually)

Only two of my uncle is into electronics (digital).

Then Y U No like 80% of your family

For once, I thought you were going to troll that you actually know more electronics than you claim you know

Mr.Kickass said:
Then Y U No like 80% of your family

For once, I thought you were going to troll that you actually know more electronics than you claim you know

No

I used to play around with dad's toolkit and flashed whole main with wrong connection on a bulb. I was at class 5 or something then.

Gradually I found my interest on Computers (Specially Software

).

That's why I'm here to seek help from all of you. As most of them are into Electrical and don't know these things.

But in digital electronics there are only two people in my family, and in company they do all these I know, but it's kinda odd to ask them every single thing. So I thought of learning the basics myself from these videos.

krishnandu.sarkar said:
But in digital electronics there are only two people...

What a symmetry btw !

I think you have an advantage here. You like software but have a wealth of family knowledge to draw from. Electronics is actually a very large field. The major areas of study include(snap taken straight out of the book written for beginners, Electronics Explained by Louis Frenzel Page 4, Chapter 1)

[IMGG]*www.thinkdigit.com/forum/attachment.php?attachmentid=12502&d=1382018648[/IMGG]

There is just so much to learn. Most people learn microcontrollers. You already have coding experience which is why popular options like embedded systems suits you. Once you get past this elementary phase of learning, you are on your own.

Still, if one wants to master every area then I sincerely wish that person a very long life

^^Yeah I understand that

As my dad used to work on Kolaghat Power Plant so his area and my other two uncle's area is different, as they work on BPL Medicare and deals with Medical Equipment Fixing (just like TV, Radio and all).

One of my maternal uncle have his shop of 1st category in the image i.e. Fixing TV, Radio etc.

And another maternal uncle is into Tehri Power Project, dad used to say he works on 800KVA Phase or something like that.

Two of my cousin also in the same field of working on Light, Fan, Fridge, Wiring the House and all

If I said something wrong above, mercy me

I don't know much of the meanings

Anyway, it's going too much offtopic

I'll continue with the videos and will surely seek help from you all if stuck

Too much to cover, but I love All About Circuits : Free Electric Circuits Textbooks It's so simple and easy to understand. Even a guy from non technical background will understand it

True, that. It wouldn't be long before someone goes :offtopic:

IMO if you liked All About Circuits then you can dig this site Kuphalt's Lessons in Electric Circuit written by the same guy who has prepared the tutorials

Mr.Kickass said:
True, that. It wouldn't be long before someone goes

IMO if you liked All About Circuits then you can dig this site Kuphalt's Lessons in Electric Circuit written by the same guy who has prepared the tutorials

Thanks. But looks same tutorials.

Anyone here into Texas Intruments MCUs - MSP430, Stellaris, Tiva C Series, C2000...?

OT : Anybody with info about importing stuff from US please help..
I need some advice about importing a BeagleBone Black from a relative who is returning from US. I read this article mentioned by Vyom in the other thread. It says circuit boards, populated boards are banned..
Since BBB is a populated board is that also banned from import?
If its marked as a 'Gift' is it exempt from duty?

Any good online store from where I can find servos for cheap price? I need 4 to 8 of them.

Shah said:
Any good online store from where I can find servos for cheap price? I need 4 to 8 of them.

Vegakits has some decent deals. The best will be checking out the local stores, where u can look for variety.

d3p said:
Vegakits has some decent deals. The best will be checking out the local stores, where u can look for variety.

URL of Vegakits??

some site lists are here, but donno how trustable they are.
Latest from around the Web: Electronics Hobbyist supply websites in India

Once again I went digging the Beaglebone Black and here is what I gathered,

Their site lists only the authorized distributors so I checked with a few of them. There is hardly a price difference between the two of them but others are including the shipping charge so it costs a bomb :shock:

1. Sumeet Instruments sells at around 3,875
2. Element14 offers the same thing at a slightly higher price of 3,900
3. Mouser Electronics shocks everybody with a price tag of $130

Originally, the Beaglebone Black costs $45~INR 2769.39 but these guys charge you around 4k so an extra 1k~1.2k above the quoted price. Mouser, for example charges $90~INR 2462.60 as shipping charges which is nearly the price of the board itself

and at a total of $130~INR 8003.45 it is a little under 3 times the original price :blink:

Verdict: Not worth the costs involved. Better stick to Arduino at the moment

EDIT: The link ico posted sometime back doesn't have the stock but it shows the price around INR 4000 thus confirming INR 3900 to be the average price

icebags said:
some site lists are here, but donno how trustable they are.
Latest from around the Web: Electronics Hobbyist supply websites in India

The legit ones are already there, can't say about others though. During my final year project some of my friends bought parts from Kits N Spares as we're from Delhi. They also ordered from SparkFun though(expensive IMO)

Mr.Kickass said:
Verdict: Not worth the costs involved. Better stick to Arduino at the moment

+1. Need it badly but too expensive everywhere :cry:

You can consider TI MCUs. They are becoming quite popular and are way cheaper and better than Arduino.

quagmire said:
OT : Anybody with info about importing stuff from US please help..
I need some advice about importing a BeagleBone Black from a relative who is returning from US. I read this article mentioned by Vyom in the other thread. It says circuit boards, populated boards are banned..
Since BBB is a populated board is that also banned from import?
If its marked as a 'Gift' is it exempt from duty?

Anyone?

Anyways heres a kickstarter : HDMIPi Affordable 9" High-Def screen for the Raspberry Pi by Alex Eames - RasPi.TV — Kickstarter

£65 is still on the expensive side but if such a display is really necessary, IMO its worth it..

quagmire said:
You can consider TI MCUs. They are becoming quite popular and are way cheaper and better than Arduino..

which model is it ? and how to program them ?

i was thinking about playing with some microchip chips, but apparently we will need a pickit tool for programming. and thats expensive.

^Microcontroller | MCU - Overview - TI.com

The inexpensive ones are : MSP430 and Tiva C Series..

Pricing of MSP430 and Tiva C Series is under 12$. Both are much better than Arduino in all respects..

Take a look at introductory videos and the datasheet of both the MCUs..

Link for their official TI forum and community.

MSP430 has become so popular, its replacing 8051 Microcontroller in ECE course..

I have been using Tiva C Series for quite some time now and have totally fallen in love with it.

Highly recommended for all engineering students and OSH enthusiasts..

^studying on that.

anyways, i am having an weird problem here.

tried to run some atmega8s (bootloader ng + blink sketch) at breadboard with minimal setup (i.e. 1x xtal, 2x 22pf, 1x10k and power connection), and they refused to work. but the same is working on the freedruino board.

i tried using 328s (uno), they are working on both freedruino board and breadboard minimal setup.

how strange. atmega8s need some extra care or what ? :-?

made a simple clock with 16x2 and arduino.

anyways, who has first hand experience with interfacing sd /mmc card with arduino ? i wanted to capture night time temperature log into an mmc card with an lm35 tempo sensor this winter. but i am kinda busy and getting mad with ork, amd may not be able to do it anytime soon.

anyone else wanna try ?

Just ordered an Induino board along with the Starters Kit from Simple Labs.co.in

congos ! now, make sure this doesn't be your last post here.

icebags said:
congos ! now, make sure this doesn't be your last post here.

Thanks! Still excited about it. It seems like I will receive it by next Tuesday/Wednesday. Fingers crossed.

icebags said:
made a simple clock with 16x2 and arduino.

anyways, who has first hand experience with interfacing sd /mmc card with arduino ? i wanted to capture night time temperature log into an mmc card with an lm35 tempo sensor this winter. but i am kinda busy and getting mad with ork, amd may not be able to do it anytime soon.

anyone else wanna try ?

Check out Jeremy Blum's Tutorial on Data logging and SD cards..

Just got my package. Quite excited!

anybody running raspberry pi with debian/ubuntu?

Shah said:
Just got my package. Quite excited!

congos, what project you are thinking to do as starter ?

avinandan012 said:
anybody running raspberry pi with debian/ubuntu?

krishnandu sarkar is running something, but not sure what it is. we never asked, and he never told. :-o

icebags said:
congos, what project you are thinking to do as starter

I have been figuring out what all I can do with the board and the kit I got. Don't have any big ideas.

BTW, Can I use functions with parameters in the sketches?

avinandan012 said:
anybody running raspberry pi with debian/ubuntu?

Yup. Me running raspbian.

Shah said:
I have been figuring out what all I can do with the board and the kit I got. Don't have any big ideas.

BTW, Can I use functions with parameters in the sketches?

Yes, why not..
Read up on Interrupts and Interrupt Service Routine. I think that will be helpful. The best forum such info is AVRFreaks.

quagmire said:
Yes, why not..
Read up on Interrupts and Interrupt Service Routine. I think that will be helpful. The best forum such info is AVRFreaks.

Thanks!

^Start following any Project series on Arduino with increasing difficulty (like Jeremy Blum Arduino video series).
You can easily get the components that they use from local electronics retail shops.
Also subscribe to magazines like EFY, Servo, Everyday Practical Electronics, Nuts and Volts, Circuit Cellar etc. They have great tutorials esp. for Arduino.

not many posts recently :chinscratch:

. anyways, to bump things up i will post my little recent arduino work.....

this winter has been very hot (temp at 2 am night).....

*i.imgur.com/4LccnGu.jpg

temp isn't very accurate, cause atmega has 1024 step precision and doesn't support analog reference below 1.1v. i did set aref @ something like 2.04v. so 2.04/1023 =~0.002v like precision, and also the sensor is said to be accurate to 1 digit after decimal. overall it may be off by 0.5 or so.....

i have not yet made the logger, need to get a 3.3v ldo regulator for the card, which is not available locally and i think i will order it online later. :/

people have become quite quiet. *l.yimg.com/us.yimg.com/i/mesg/emoticons7/39.gif

still, i am gonna my share pics of my latest dyi datalogger.....

*i.imgur.com/uYynDOw.jpg
*i.imgur.com/IcxsIKK.jpg

somehow managed to put together the smd, crap soldering.

*i.imgur.com/4vroynu.jpg

thinking about making a temperature feedback controlled arduino soldering station. may be that will improve my soldering skills ?

any ideas ?

Can anyone suggest me some ideas to make a simple mini project with/without microprocessor? I need to submit one for my Sem 2 Practicals before February. BTW, I need it to be as simple and cheap as possible.

what u study and what kind of project u need ?

Shah said:
Can anyone suggest me some ideas to make a simple mini project with/without microprocessor? I need to submit one for my Sem 2 Practicals before February. BTW, I need it to be as simple and cheap as possible.

Check this:

quagmire said:
Subscribe to magazines like EFY, Servo, Everyday Practical Electronics, Nuts and Volts, Circuit Cellar etc. They have great tutorials

@icebags : Some great work buddy. :doublethumb:

Was busy some project of mine, will post details later in this thread.

Some questions:

1. Where did you get the Pin Headers for SD card connection?

2. How did you make the PCB? Looks the rails aren't very neat.
I usually get great results with Toner Transfer method. Even tried 0.65mm pitch TSSOP trace with fairly good result :wink:

Some things I use that help in soldering: Desoldering wick, desoldering pump, Flux of good quality, chisel tip and sharp tips for gun

3. Which IC is that? Can you post schematic?

4. Why dont you use a IC base? That way you can reuse the IC later, or replace in the case of malfunction.

5. So could you try USBasp?

quagmire said:
Some questions:

1. Where did you get the Pin Headers for SD card connection?

2. How did you make the PCB? Looks the rails aren't very neat.
I usually get great results with Toner Transfer method. Even tried 0.65mm pitch TSSOP trace with fairly good result
Some things I use that help in soldering: Desoldering wick, desoldering pump, Flux of good quality, chisel tip and sharp tips for gun

3. Which IC is that? Can you post schematic?

4. Why dont you use a IC base? That way you can reuse the IC later, or replace in the case of malfunction.

5. So could you try USBasp?

thanks. here are the ans:

1.

those are 90 degree berg pins. read more here, till the last: Cheap DIY SD card breadboard socket these guys should get noble prize for such ingenious ideas.

2. used fine tip permanent black marker with refill inks, i kinda forget how to use eagle at times, also there is no eagle library for 1117 (i need to learn how to make eagle libs), so just painted the line with a steel scale.

3. its 3-state buffer ic, 74HC125 with supply voltage by ic AMS1117 3.3volts (that smd 3 pin one). 74HC125 gives max output as its supply voltage , that would be 3.3v in this case. i.e. it is serving 2 purposes, (a) stabilizer buffer and (b) level shifter from 5v to 3.3v where sd cards operate.

schematic with resistor voltage divider(sd card pins are marked in reversed order though):
*arduinodiy.files.wordpress.com/2012/03/sd-card_thumb.jpg?w=523&h=443
with buffer:
*arduinodiy.files.wordpress.com/2012/04/sd-card2_thumb.jpg?w=525&h=445
my complete circuit:
*i.imgur.com/3BFr9Kn.jpg

4. i dont like the pcb layout, i was too busy thinking how to get everything into that small board, and i messed up some connections, if the ic goes bad, i will make a 2nd version of this with less jumpers and even compact form factor. but this wont go bad anytime soon i think, i even stabilized their power supplies with such a nice big bypass cap.

5. yah sure, but don't really need it right now, cause the arduino board is working well as programmer for other chips, but i have all components for usbasp, so that i can try it anytime i need.

Great. Thanks for the info.

^ did u ever try to use the internal oscillator of atmega8 for minimal setup ?

^Yes, but on a Atmega32. Wrote the fuse bits carefully and ran a basic LED flashing program on a pin.

Can anyone help me with powering a IR LED? I recently,got it along with a tsop 1738. The receiver circuit I designed is working well when I press a button on a Remote pointing the TSOP 1738. But, I can't make the IR LED to emit at 38kHz. I even tried using IC555 as astable multivibrator to power the IR LED. But, I can't make it to work.

what voltage u putting at led ?

1. replace ir led with normal red led and see if its glowing.
2. while ir led circuit is on, see the ir led through ur mobile video cam, if its glowing.

and let us know what u find.

With 5V (Using 9V battery and an IC 7805 to regulate it to 5V)

1. I already tried it and a normal LED is working.

2. Again, I already tried it. No success. But, Cameras can't detect IR of all range.

check 2 with steady power at ir led. dont put any frequency, does it glow through video cam ?

icebags said:
check 2 with steady power at ir led. dont put any frequency, does it glow through video cam ?

No. It's not glowing still. I will get another IR LED today and check if it works. If the new one works, then the problem is with the IR LED otherwise with my circuit.

i think the led is bad.

anyways if u put 5v at 555, the output is normally 1.7 -2v lower than the input, so, use some 1k-2.2k resistor to limit current through led. or it may burn up.

icebags said:
i think the led is bad.

anyways if u put 5v at 555, the output is normally 1.7 -2v lower than the input, so, use some 1k-2.2k resistor to limit current through led. or it may burn up.

Gonna get some IR LEDs today. Will check them with 1k resistor.

EDIT: Can you suggest some online stores where I can find all the components?

Bhasha e-Store - Bhasha Technologies e-Store
Ventor Technologies India, Online Electronic Component Shop

i purchased from ventor before they ship quite fast, i hope they are reliable.

icebags said:
Bhasha e-Store - Bhasha Technologies e-Store
Ventor Technologies India, Online Electronic Component Shop

i purchased from ventor before they ship quite fast, i hope they are reliable.

Thanks.

icebags said:
i think the led is bad.

anyways if u put 5v at 555, the output is normally 1.7 -2v lower than the input, so, use some 1k-2.2k resistor to limit current through led. or it may burn up.

With a new LED in place, It seems working. But, It isn't emitting at 38kHz. Any other circuits to make the IR LED to emit at 38kHz.

have u tried measuring the actual frequency of the 555 output ?

resistors & capacitors have tolerance issues, they hardly give the actual value.

icebags said:
have u tried measuring the actual frequency of the 555 output ?

No. How do I do that?
BTW, I am thinking of using variable resistors.

lemme write u a sketch :

Code:

int l_SensorValue = 0;
int l_RefValueMin;
int l_RefValueMax;
int l_tolerance = 10;
int l_comparevalue ;

unsigned long l_t0 = 0;  // 0 cycle
int           l_t1 = 0;  //.5 cycle
unsigned long l_t2 = 0;  // 1 cycle

void setup() {
  Serial.begin(9600);    // initialize serial communication at 9600 bits per second:
  l_RefValueMin = 205-l_tolerance;
  l_RefValueMax = 205+l_tolerance;
}

void loop() { 
	l_t0 = 0;
	l_t1 = 0;
	l_t2 = 0;
	
	if (l_SensorValue == 0) {
		l_SensorValue = analogRead(A0);
	}
	l_comparevalue = analogRead(A0);
	
	if ( l_comparevalue > (l_SensorValue+l_tolerance) && l_comparevalue > l_RefValueMax )  // tolerance //initiate during change state
	{
		while(1<2)  //infy loopie
		{
			l_comparevalue = analogRead(A0);
			if ( l_t0 == 0 && l_comparevalue < l_RefValueMin )
				l_t0 = micros();              //record starting time of wave
			else if (l_t1 == 0 && l_comparevalue > l_RefValueMax )
				l_t1 = 1;             //mark half cycle time of wave  //commenting micros()
			else if ( /*l_t2 == 0*/ l_t1 !=0 && l_comparevalue < l_RefValueMin ) {
				l_t2 = micros();             //record full cycle time of wave
				//l_period = l_t2-l_t0;
				l_SensorValue = 0;
				break;  //exit loop. !CHECK!
			}
		}
		Serial.println(1000000/(l_t2-l_t0));    //print frequency // this prog may work for up to 50khz ? with ?? error %.
		delay(100);
	}
}

1) make sure the 555 o/p is less than 4.5 volts all the time or arduino may get damaged, cause arduino analog ins can max handle 5v. (put 555 o/p to on state and use a multimeter to measure the dc voltage)
2) connect 555 gnd to arduino gnd, 555 out to arduino analog pin A0.
3) connect arduino to pc, when arduino is up & running, open serial monitor from arduino ide in pc.
4) see whats the output ?
5) do all above at ur own risk

, and stay away from mains, just rely on battery power.

i have not debugged / tested the code & my C skills are numb, not getting much free time for electronics..... will u do it for me ? *l.yimg.com/us.yimg.com/i/mesg/emoticons7/5.gif

pls review the code for any mistakes, before running.

use this code for waves < 50KHz only.

icebags said:
lemme write u a sketch :

Code:

int l_SensorValue = 0; int l_RefValueMin; int l_RefValueMax; int l_tolerance = 10; int l_comparevalue ; unsigned long l_t0 = 0; // 0 cycle int l_t1 = 0; //.5 cycle unsigned long l_t2 = 0; // 1 cycle void setup() { Serial.begin(9600); // initialize serial communication at 9600 bits per second: l_RefValueMin = 205-l_tolerance; l_RefValueMax = 205+l_tolerance; } void loop() { l_t0 = 0; l_t1 = 0; l_t2 = 0; if (l_SensorValue == 0) { l_SensorValue = analogRead(A0); } l_comparevalue = analogRead(A0); if ( l_comparevalue > (l_SensorValue+l_tolerance) && l_comparevalue > l_RefValueMax ) // tolerance //initiate during change state { while(1<2) //infy loopie { l_comparevalue = analogRead(A0); if ( l_t0 == 0 && l_comparevalue < l_RefValueMin ) l_t0 = micros(); //record starting time of wave else if (l_t1 == 0 && l_comparevalue > l_RefValueMax ) l_t1 = 1; //mark half cycle time of wave //commenting micros() else if ( /*l_t2 == 0*/ l_t1 !=0 && l_comparevalue < l_RefValueMin ) { l_t2 = micros(); //record full cycle time of wave //l_period = l_t2-l_t0; l_SensorValue = 0; break; //exit loop. !CHECK! } } Serial.println(1000000/(l_t2-l_t0)); //print frequency // this prog may work for up to 50khz ? with ?? error %. delay(100); } }

1) make sure the 555 o/p is less than 4.5 volts all the time or arduino may get damaged, cause arduino analog ins can max handle 5v. (put 555 o/p to on state and use a multimeter to measure the dc voltage)
2) connect 555 gnd to arduino gnd, 555 out to arduino analog pin A0.
3) connect arduino to pc, when arduino is up & running, open serial monitor from arduino ide in pc.
4) see whats the output ?
5) do all above at ur own risk , and stay away from mains, just rely on battery power.

i have not debugged / tested the code & my C skills are numb, not getting much free time for electronics..... will u do it for me ? *l.yimg.com/us.yimg.com/i/mesg/emoticons7/5.gif

pls review the code for any mistakes, before running.

use this code for waves < 50KHz only.

Will reply after I try it out.

Thanks.

My first QuadBot and it can walk.

*www.thinkdigit.com/forum/attachment.php?attachmentid=13959&d=1395551260

Shah said:
My first QuadBot and it can walk.

View attachment 13959

excellent man, !!

Nerevarine said:
excellent man, !!

I actually made it for the upcoming Expo (which based on Arduino :hyper:

) in my college. Tomorrow is the demo. I am thinking of making it to dance before that. A dancing QuadBot will be cool, won't it be?

Shah said:
I actually made it for the upcoming Expo (which based on Arduino ) in my college. Tomorrow is the demo. I am thinking of making it to dance before that. A dancing QuadBot will be cool, won't it be?

Awesome!!!

Shah said:
My first QuadBot and it can walk.

u're alive !! i thought arduino chip exploded while u trying to experiment iwth my untested code :ashamed:

, and something happened. *s.yimg.com/lq/i/mesg/emoticons7/71.gif heck i didn't even get the courage to post here. :ashamed:

anyways congrats for the quadbot, nice job. :clap2:

icebags said:
u're alive !! i thought arduino chip exploded while u trying to experiment iwth my untested code , and something happened. *s.yimg.com/lq/i/mesg/emoticons7/71.gif heck i didn't even get the courage to post here.

anyways congrats for the quadbot, nice job.

lol. I didn't even had time to test that code. I am thinking of getting a Photodiode to make the job easier. I am lil bit busy for the next two weeks. Will test that code afterwords.

amjath said:
Awesome!!!

Thanks.

[MENTION=129731]Shah[/MENTION] : Great job buddy. :thumbs:

It would be great if you shared a video of the demo.

Nice chassis and nice use of stackable shields.

Hmm I see IR receivers and lots of servos used. Nice..

Plz give more info on your bot. Like DOF, chassis used, Servos and PWM drivers used, shields used, battery, MCU and voice thing that you're telling about.

G

[MENTION=129731]Shah[/MENTION] good...how did u make the plastic body?...is it ready made parts or you made yourself from some material by cutting?

gopi_vbboy said:
[MENTION=129731]Shah[/MENTION] good...how did u make the plastic body?...is it ready made parts or you made yourself from some material by cutting?

I had visited Chennai, last Thursday. I bought the chassis from there only. BTW, It was a DIY kit and it had the laser cut plates, screws, battery holder, a servo shield and 8 servos.

quagmire said:
[MENTION=129731]Shah[/MENTION] : Great job buddy.
It would be great if you shared a video of the demo.
I wish I had enough bandwidth to upload it over here.
Nice chassis and nice use of stackable shields.
I didn't design the chassis, I just bought it.
Hmm I see IR receivers and lots of servos used. Nice..
There are 8 servos and Only one of the two TSOP receivers is interfaced to control the bot using IR Remote. (I hope You can see the white Remote in the right of that pic)
Plz give more info on your bot. Like DOF, chassis used, Servos and PWM drivers used, shields used, battery, MCU and voice thing that you're telling about.
Each leg has 2DOF, Servos are SG90(TowerPro SG90 Servo Specifications and Reviews) , the Servo shield also came with the chassis. Voice thing? I don't get it. I was talking about making it to dance.

Replies in bold.

BTW, I tried to program it to dance and the first attempt failed.

From where can I get Tower Pro MG-995 and HXT900 servos online? I need a few of them. I am getting MG-995 for around 1.5k INR. Is it a good price? I can't find the HXT900 anywhere (not even on eBay)

^
search *shop.sumeetinstruments.com/index.php?route=product/product&path=49_87&product_id=965
then search *www.thinkdigit.com/forum/open-source/176760-open-source-hardware-thread-4.html#post2021158
then @ ebay.in, ask about it to "onlinetps" seller, if they can arrange it, then ask them to list it.
if still not found then idk.

found some cool stuff :

any idea why float to string is not taking place properly ?

i used "sprintf(f2str,"%.2f",l_value);" to put value (float) to f2str (char[30]) and when i am printing f2str, i am only getting "?".

icebags said:
any idea why float to string is not taking place properly ?

i used "sprintf(f2str,"%.2f",l_value);" to put value (float) to f2str (char[30]) and when i am printing f2str, i am only getting "?".

have you included the header file "math.h"? AFAIK, sprintf returns a negative if the conversion fails. I might be wrong, though.

but l_value is just the name of floating variable, why does the name matter ?

and i don't think sprintf needs math, it already compiled successfully.

G

icebags said:
any idea why float to string is not taking place properly ?

i used "sprintf(f2str,"%.2f",l_value);" to put value (float) to f2str (char[30]) and when i am printing f2str, i am only getting "?".

1.Have you checked compiler documentation for sprintf you are compiling on?Does it support those formats?
2.What is value of float?garbage?

thanks for the suggestions, it seems a compiler issue, cause, the same works in gcc.

anyways, i handled this case by storing before decimal and after decimal points in two different integers.

I recently got a ITead BT Shield v2.2 and I have been experimenting with it. I have programmed it and developed an App for my WP to connect with it. Now, I can successfully connect with the shield but, I can't send any data to the shield from my WP. Further inspection revealed that BTSoftwareSerial.available() function is always false. How can I fix it?

S

I recently ordered some components from ebay.com.inventory includes a Bluetooth shield for Arduino and two atmega a16.
can anyone share some experience with ebay.com and international standard shipping.
and how this ebay grantee works in case of international standard shipping will they refund my money if i dont get the item as they say ?
the seller is asking me to pay a small amount to send the items through a registered post.the seller is based in china.
guys i need a little advice on this.

tried basic oscilloscoping with nokia 5110 lcd shield:
*i.imgur.com/1kYfy0P.jpg

got excited, & bought 2.4" high resoltion tft colour touch display off ebay, finding driver was difficult though, but found something ultimately what works. will try to tweak the driver a bit for suiting my needs better:
*i.ebayimg.com/00/s/MTAwMFgxMDAw/z/bMoAAOxy0NtTDxfI/$_12.JPG

also bought a pair of NRF24L01 2.4GHz wireless transceiver modules to try out wireless data comms:
*i.ebayimg.com/00/s/MjI3WDQ3Mg==/z/jDAAAOSwcnpTnHJ1/$_12.JPG

previously bought: nokia 3110 replacement screen, but didn't know connecting it will be beyond my capabilities. rs.150 wasted. :-x

*i.ebayimg.com/00/s/NzUwWDEwMDA=/z/7MoAAOSws65TpEpe/$_12.JPG

what exactly will u be building.. a lcd fan controller for your cabinet ?

nope, a plain & simple oscilloscope was the goal, but arduino itself is not any good for waves >2KHz or ~8KHz with ADC register tweaks. i still want to build one, but need one high speed dedicated ADC chip to see waves of 50kHz range, that i wanted.

other than that, i am thinking of putting the b/w lcd onto a 5w solar panel that i have, to monitor power output and see the daylong power curve. just some hobby stuff, nothing special. :razz:

icebags said:
tried basic oscilloscoping with nokia 5110 lcd shield:
*i.imgur.com/1kYfy0P.jpg

got excited, & bought 2.4" high resoltion tft colour touch display off ebay, finding driver was difficult though, but found something ultimately what works. will try to tweak the driver a bit for suiting my needs better:
*i.ebayimg.com/00/s/MTAwMFgxMDAw/z/bMoAAOxy0NtTDxfI/$_12.JPG

also bought a pair of NRF24L01 2.4GHz wireless transceiver modules to try out wireless data comms:
*i.ebayimg.com/00/s/MjI3WDQ3Mg==/z/jDAAAOSwcnpTnHJ1/$_12.JPG

previously bought: nokia 3110 replacement screen, but didn't know connecting it will be beyond my capabilities. rs.150 wasted.
*i.ebayimg.com/00/s/NzUwWDEwMDA=/z/7MoAAOSws65TpEpe/$_12.JPG

Cool. Nice to see a post on this thread after a long time. And, keep this thread alive.

Awesome.

Shah said:
Cool. Nice to see a post on this thread after a long time. And, keep this thread alive.

yah, kinda lonely. u ppl should do some stuff too. :-o

been lurking around the interwebs to find my next board to kill some time (one month) very interested in Beaglebone Black after watching the video below.

I'm thinking of buying a board instead of a Android TV stick, but I don't think these are that powerful for media center.

S

hello guys
does anyone have any experience with the 28BYJ-48 stepper motor ?
i cant find a gear to fit into the motor i mean in the outer arm.
[MENTION=44484]icebags[/MENTION] what kind of MCU did you use with the nokia 5110?

atmega 328 or 8, as usual. library is available at adafruit.

Lately, I have been thinking about developing a Rubik's Cube Solver robot using an Arduino. I have decided to design that in a way where the Arduino scans the colours of the Rubik's cube and sends it to a PC or a Phone to generate an optimal solution. Then, the Arduino MCU will execute the solution generated by PC and execute it using servo arms.

So far, I'm sure about all the things except the Colour scanning. I want some help with it as I haven't used any colour sensor at all. Can you guys tell me what Colour sensor should I prefer?

^ Shah, I recommend you use a phone/webcam as a primary camera to completely scan the cube. An image processing algorithm running on (say OpenCV) phone/laptop will accurately give the colors and the individual turns that you have to make. You can then actuate the result using Arduino.
It is possible to interface a camera with Arduino (check Omnivision cameras) but it is not possible to achieve a decent frame rate or resolution that you require, plus those cameras are expensive and not available in India. Webcams as cheap as 6$ are available online..

Else you could ditch the Arduino and graduate to a Raspberry Pi or BeagleBone which is a complete solution not requiring a PC at all.

quagmire said:
^ Shah, I recommend you use a phone/webcam as a primary camera to completely scan the cube. An image processing algorithm running on (say OpenCV) phone/laptop will accurately give the colors and the individual turns that you have to make. You can then actuate the result using Arduino.
It is possible to interface a camera with Arduino (check Omnivision cameras) but it is not possible to achieve a decent frame rate or resolution that you require, plus those cameras are expensive and not available in India. Webcams as cheap as 6$ are available online..

Else you could ditch the Arduino and graduate to a Raspberry Pi or BeagleBone which is a complete solution not requiring a PC at all.

Thanks for the reply. I'll use my Phone's camera then.

(I don't have a webcam, Time to get one.)

The thing is even RaspPi can't find the optimal solution in a short time. So, To find an optimal solution in a short time, I have to use a PC.

Hello [MENTION=129731]Shah[/MENTION],finally i am home and made a purchase of arduino
as you said me,i think i have ordered a clone one for around Rs 780 :mrgreen:

UNO R3 Development Board FOR Arduino Compatible USB Cable NEW | eBay
is the purchase enough for me to understand all the basics?
and you said a 9 volt battery with a resistor and i will never break the board?

vedula.k95 said:
Hello [MENTION=129731]Shah[/MENTION],finally i am home and made a purchase of arduino
as you said me,i think i have ordered a clone one for around Rs 780
UNO R3 Development Board FOR Arduino Compatible USB Cable NEW | eBay
is the purchase enough for me to understand all the basics?
and you said a 9 volt battery with a resistor and i will never break the board?

That will do.

BTW, I told about a 9V battery with a IC7805 (Voltage Regulator) to power it. You will need some capacitors to make a voltage regulation circuit.

- - - Updated - - -
[MENTION=273316]vedula.k95[/MENTION] Here is a pic of a Voltage Regulation circuit that I tried soldering on a PCB.

*www.digit.in/forum/attachment.php?attachmentid=15046&d=1418271767

The capacitors I have used are 10 uF and 100 uF (by u I mean micro)

- - - Updated - - -

Get yourself a breadboard, multimeter and a few capacitors, resistors and transistors. Also LEDs. They will be very much useful for you.

vedula.k95 said:
Hello [MENTION=129731]Shah[/MENTION],finally i am home and made a purchase of arduino
as you said me,i think i have ordered a clone one for around Rs 780
UNO R3 Development Board FOR Arduino Compatible USB Cable NEW | eBay
is the purchase enough for me to understand all the basics?
and you said a 9 volt battery with a resistor and i will never break the board?

u may just power it through usb cable. battery + converter can be used for standalone app.

meanwhile my latest arduio diy :
*i.imgur.com/0gMEt4t.jpg?1

pls purdon the bad q pic and the piece of supporting paper !

icebags said:
meanwhile my latest arduio diy :
*i.imgur.com/0gMEt4t.jpg?1

pls purdon the bad q pic and the piece of supporting paper !

Great work, [MENTION=44484]icebags[/MENTION]. What microprocessor is it? Also, what are the list of components you used?

^nothing much, just one atmega8, with op-amp (LM324) buffer interfaced at it's 4 analog inputs. 1 button is also there u see at right side corner, for menu navigation on 16x2 display.

i actually thought u would ask whats its purpose ......

S

icebags said:
^nothing much, just one atmega8, with op-amp (LM324) buffer interfaced at it's 4 analog inputs. 1 button is also there u see at right side corner, for menu navigation on 16x2 display.

i actually thought u would ask whats its purpose ......

whats its purpose ??
connecting the lcd to the micro is a pain

sankar said:
whats its purpose ??
connecting the lcd to the micro is a pain

connecting 16x2 or nokia ones with pcb connectors is not pain ...... just try it.

here, can u guess the purpose now ?

icebags said:
connecting 16x2 or nokia ones with pcb connectors is not pain ...... just try it.

here, can u guess the purpose now ?

I am too

to get the purpose even after watching the video thrice. :lol:

BTW, Was it to build a DIY Arduino from sctrach?

hmmm i think it's because i just pressed button twice in the last and it skipped the first monitor menu, and u could not see the multiplied port reading menu.

well, its not exactly development board, but can better be referred as application board. if u see 1:15, in the display there r 4 analogue readings from 4 buffered analog ports (via those black screw terminals) and the second mode is simple temperature monitor from analog port 0.

this is why in the first display the 0th reading is low, that's the temperature sensor voltage o/p.

anyways, for the 4 reading display, the button can be used to properly set the reading of each analog port, by setting multiplier option. as u can see i am setting them from 1:43.

this is because in this board i used lm385 voltage reference diode for 1:235V, its much better than the arduino internal voltage reference.

so, lets say i want to measure a 5-7 V source, then i will be using a 1:10 voltage divider resistor network, to get the o/p in the range of 0-1.235V. so, to display actual voltage on screen i will need to set multiplier for that port , which would be x11 if i use a 100k & 10k resistor for voltage divider.

now ask me why i go through all the trouble to display 4 analog port readings on the display at once, whats the purpose ? :aaargh:

icebags said:
hmmm i think it's because i just pressed button twice in the last and it skipped the first monitor menu, and u could not see the multiplied port reading menu.

well, its not exactly development board, but can better be referred as application board. if u see 1:15, in the display there r 4 analogue readings from 4 buffered analog ports (via those black screw terminals) and the second mode is simple temperature monitor from analog port 0.

this is why in the first display the 0th reading is low, that's the temperature sensor voltage o/p.

anyways, for the 4 reading display, the button can be used to properly set the reading of each analog port, by setting multiplier option. as u can see i am setting them from 1:43.

this is because in this board i used lm385 voltage reference diode for 1:235V, its much better than the arduino internal voltage reference.

so, lets say i want to measure a 5-7 V source, then i will be using a 1:10 voltage divider resistor network, to get the o/p in the range of 0-1.235V. so, to display actual voltage on screen i will need to set multiplier for that port , which would be x11 if i use a 100k & 10k resistor for voltage divider.

now ask me why i go through all the trouble to display 4 analog port readings on the display at once, whats the purpose ?

Enough of suspense, Break the ice, [MENTION=44484]icebags[/MENTION]

Shah said:
Enough of suspense, Break the ice, [MENTION=44484]icebags[/MENTION]

there is not much suspense actually, just because multimeters show only 1 reading at once, consider this as 4 in 1. say when building a new ckt, i can monitor the input voltage at one, input current at an another, and there will be 2 more ports for testing / debugging...... just like that. *s.yimg.com/lq/i/mesg/emoticons7/29.gif

S

icebags said:
connecting 16x2 or nokia ones with pcb connectors is not pain ...... just try it.

here, can u guess the purpose now ?

could not figure out the second micro with the 14 pin.
what is it?
BTW how did you latch that switch? did you use the interrupt to trap the switch ?

Guys I have an old micromax android phone lying around whose touch is busted but the display works fine.. Is it possible to remove it and use it with say ? a raspberry pi ?
Link to any tutorials on how to get started

sankar said:
could not figure out the second micro with the 14 pin.
what is it?
BTW how did you latch that switch? did you use the interrupt to trap the switch ?

>.> thats just lm 324 opamp for buffering the mc analog inputs, duh ! and recently i have found another good use for this display board, no need to ask me what, i will post pics and details soon

and the button is just connected to a digital input pin, no interrupts, just wrote a little subprogram to detect whether its a long press or a short press, when there is change of state in digital pin. but debouncing takes some experimentation before, to be taken cared properly.

Nerevarine said:
Guys I have an old micromax android phone lying around whose touch is busted but the display works fine.. Is it possible to remove it and use it with say ? a raspberry pi ?
Link to any tutorials on how to get started

firstly, a driver program library needs to be written, based on the display chip - by going through the datasheet, which is a time consuming job and requires good understanding of these stuff ! people use some common displays, which have readymade library or details avaible, if mmx lcd is not of them then .....

then, those fone displays have kinda microscopic connectors, and are very difficult to connect by hand, so, unless u have the proper connector, .....

So, What's the cheapest UNO compatible Wi-Fi shield that I can get? All Wi-Fi shields I found are well above 4K. I'm looking for something around 1K INR. The cheaper the better.

^Shah, WiFi shields are expensive, go for standard ones only, lots of China fake shields are selling online..
If WiFi is what you want, you can try this
Serial WIFI Transceiver Module ESP8266 [WWI8266ESP] - $3.24 : Elecrow bazaar, Make your making more easy

quagmire said:
^Shah, WiFi shields are expensive, go for standard ones only, lots of China fake shields are selling online..
If WiFi is what you want, you can try this
Serial WIFI Transceiver Module ESP8266 [WWI8266ESP] - $3.24 : Elecrow bazaar, Make your making more easy

Thanks for the suggestion.

Found the same on Amazon (Amazon.in: ESP8266: Electronics)

Looks like I have to get a breakout board along with it.

icebags said:
yup, thanks. i have also purchased a huge lot of 1watt & 0.5 watt leds, will slowly slowly try to put them at different parts of house, just thinking a way to efficiently drive them from 12/6v source !

here you go, pics !

ripple from a wall wart 12v smps, on ~600mA linear load : its noisy, too many frequencies, so, i guess triggering was a bit difficult with this substandard 10MHz scope. The main is 100KHz, but if looked closely, the rising edge has very low duration high freq MHz level ripples, with amplitude in 10s of volts.
*i.imgur.com/QC6lMcg.png

clean signal, from the 1KHz calibration port is very clear though
*i.imgur.com/wGG9P1E.png

its the most basic as it gets, 10MHz analog, good for basic studies of modulation, basic power supply design and valuation, audio amplifier design, testing & debugging and for probing into not so high frequency stuff. i want to get a DSO of 100-200MHz in future, but before that wanted a CRO for cheaper price.
it was 8k at urjakart, the HTC model. after i bought they not only reduced the price, but also included cheaper MetroQ model - same stuff from same/different chinese factory perhaps, but different indian brand names. geez, i could have saved ~1.5k with metroq model.
this is substandard to the standard 20-30MHz stuff people use at colleges, but it's okay with me for now.
i m also aware of the usb ones, but people suggested to get dedicated ones, they even warned me to get at least 20MHz models, but i didn't listen.

nice, congos, happy holling.

Didn't want to hijack the other thread, so continuing here.

So are you working on a project? Audio stuff?
Did you buy a signal generator also?

quagmire said:
Didn't want to hijack the other thread, so continuing here.

So are you working on a project? Audio stuff?
Did you buy a signal generator also?

yah better here....

well, some audio projects alright, making some small amplifiers for experimenting and causal listening purposes. but noh, didn't buy and signal generator, for audio its not very important at this moment, i can just play 1khz sine wave audio files to find where audio is clipping, and how clean it is.

but i have a signal gen in my purchase list, the lab bench ones are rather expensive, and these look better suite the hobby purpose :
AD9850 DDS Signal Generator Module 0 40MHz | eBay
AD9850 DDS DSP Signal Generator Module 0 40MHz Sine Wave FOR Arduinor KG208 | eBay

and yah for audio, made a 2 mobile amps, one with lm386 another with tda2822m : it was difficult to construct just by reading datasheet, had to go through multiple breadboard and veroboard prototypes, then had to watch videos and had to consult the experienced on youtube. finally after some nightmares, they are giving reasonably nice and clean sound. the tda2822m is still giving slight no signal hiss, but that ic has big gain and i m using ic base, so..... (blew up 2x tds2822m to get the 3rd one work nicely).

here are the pics, please pardon the green marker ink on pcb, just had to paint to avoid corrosion. u will probably wont be able to see tracks because of the ink, but i kinda tried my best for a star ground layout. also had to modify those input caps for make them work and for tuning into best suitable bass.

TDA2822M on left and LM386 on right. TDA2822M > LM386 for sound quality any day. but LM386 has sturdier build quality & doesn't fail so easily.

*i.imgur.com/M8F78l3.png

*i.imgur.com/zZ5Pq0T.jpg
(click to zoom)

also, worked on an another project, to build a charge controller, to charge a 6v lead acid from my 5w solar panel.
and currently working on arduino remote weather station project (well working on it from last winter lol), on 433MHz modules, it works, but i am still working to make it better. will share pics when completes a bit more.

and also bought a vire usbfm remote kit @Rs.105/-& and a couple of TDA2003 audio amp ics to build a neat audio listening gear.

[MENTION=145504]quagmire[/MENTION] any interesting project u working on these days ?

[MENTION=44484]icebags[/MENTION], how good are these amps compared to actual commercial stuff like fiio
I imagine, these enhance noise as well ??

Nerevarine said:
[MENTION=44484]icebags[/MENTION], how good are these amps compared to actual commercial stuff like fiio
I imagine, these enhance noise as well ??

...........

these particular ics were used in 80s or 90s in walkman and portable radio stuff. they cost ~8 - 10/- rupees each, and total building cost <50/-.

noise and stuff depend on how well the circuit boards are build, quality of power supply & greatly on the quality of the speakers used. still, even at best case scenario, these are not exactly hi-fi chips. premium brands like fiio use hi-fi chips and well designed boards, so they are obviously better. but people have done diy with those hi-fi stuff as well, and i guess some of they are happy.

a better comparison would be those frontech / zebronics / logitech / creative stereo speakers < 1000/-. i had one frontech from 2001, that used TEA2025 ship, it gave more o/p power, but the sound quality was inferior.

you may check this, but its a little technical.

[MENTION=44484]icebags[/MENTION]

A couple of my EE friends have decided on building a DAC based

AMB Laboratories

γ1 modular miniature DAC
γ1.5 miniature high-resolution USB DAC + headphone amplifier NEW!
γ2 compact high performance DAC
γ3 high resolution DAC NEW!
γ24 high performance DAC core NEW!

Right now they are confused about the viability of the project, as it may be too difficult in the later stages.. Budget is not a concern as most of the parts, they will get for free.. I was wondering if you had any advice/inputs to give and/or any other good alternative DIY DAC that may be easy enough to do as a small project of duration 3-5months

PS: Budget is not a concern as long as individual parts are ordered from companies that provide free samples via university domain (cirrus logic, wolfson dac, texas instruments etc etc)

they want to do a readymade project like this ? if they follow that site, then they will end up having the job of assembling the components together. at most they will get to do the board layout and performance analysis.

but i doubt it will be a big project.

not sure if you can really make a discrete project for usb based dac, there are those ready made chips available for that. another kit based solution is here : CS4398 CM102 CS8416IC DAC Kit 192K 24bit SPI I2S Amplifier Board | eBay

an fpga based audio dac project is much more technical, will include programming and designing. again, these are not something new, but still u better ask friends not to copy the online projects, and make use of their own creativity in designing. just take the concepts from web and get in touch with college prof.

anyone in circle made this ? seems like answer to a lot of headaches.

made with DVD / CD parts & rails :

[MENTION=44484]icebags[/MENTION]

I have seen this first one before, it really comes down to the time you have and sourcing parts can be difficult, or atleast I cant get hold of them.

hmmmmm. so, dismantling the dvd drive is the way to go?

icebags said:
hmmmmm. so, dismantling the dvd drive is the way to go?

[MENTION=44484]icebags[/MENTION] have you seen raspberry pi based ambilight clone, looks so damn amazing, youtube it and do tell how it looks

yah, cool, isn't it ? did u check greatscott tutorial ?

A

About Open Source Hardware in general and about open source phones in particular.
When someone finds an interesting project they can announce it here.
I think it's a good idea to have a thread dedicated to OSH.

The Atomo Modular Electronics System is like LEGO for electronics | TechCrunc

Atomo Modular Electronics System | Indiegog

Intersting concept

I need help in downloading program from Arduino Nano board.
My friend created sketch and uploaded on Arduino Nano.
But after that he formatted that computer and most the sketch.
How do I recover it?

TigerKing said:
I need help in downloading program from Arduino Nano board.
My friend created sketch and uploaded on Arduino Nano.
But after that he formatted that computer and most the sketch.
How do I recover it?

You want to undelete some files from your PC? How is this relevant to this thread?

W

Desmond David said:
You want to undelete some files from your PC? How is this relevant to this thread?

I think he wants to retrieve it from arduino board(some kind of rom extraction).

whitestar_999 said:
I think he wants to retrieve it from arduino board(some kind of rom extraction).

That's what I thought at first until I read:

TigerKing said:
But after that he formatted that computer

W

Desmond David said:
That's what I thought at first until I read:

Ok,I am not familiar with Arduino board.I assumed that "computer" in this case is different from Arduino & was used as a source to upload some kind of program to the board after which computer hdd was formatted.

That could be the case with a Raspberry Pi, but an Arduino is more of a microcontroller board than a full-fledged computer like a Raspberry Pi.

TigerKing said:
I need help in downloading program from Arduino Nano board.
My friend created sketch and uploaded on Arduino Nano.
But after that he formatted that computer and most the sketch.
How do I recover it?

your friend is not the only one on earth -
Downloading/Reading sketches from the Arduino?

whitestar_999 said:
Ok,I am not familiar with Arduino board.I assumed that "computer" in this case is different from Arduino & was used as a source to upload some kind of program to the board after which computer hdd was formatted.

Ok..
Computer means PC

normal one.. window OS
You can connect Arduino Nano to PC, create program/sketch through Arduino IDE, compile it, upload it to Arduino Nano through USB connection, after uploading no need for computer to run the program.
Okay.

icebags said:
your friend is not the only one on earth -
Downloading/Reading sketches from the Arduino?

But he can't remember exactly values he put in code.
How one can retrieve programming from HEX codes?

No worries, he found rough work of those codes written one of the paper.

Anyone here got experience using NDN/NFD on Rpi? Need some assistance in packet forwarding from ipv4 to NDN stack from one Pi to another.

thetechfreak said:
Anyone here got experience using NDN/NFD on Rpi? Need some assistance in packet forwarding from ipv4 to NDN stack from one Pi to another.

Just curious, what is it that you are doing?

TigerKing said:
But he can't remember exactly values he put in code.
How one can retrieve programming from HEX codes?

hex are executable codes. getting the exact source code is not possible from them. but if you learned the datasheet and assembly instructions well, you will get the commands. good to know your friend retrieved the rough work.

TheSloth said:
Just curious, what is it that you are doing?

Just trying to get two RPi to forward requests correctly using NDN. Have had some progress but don't get enough time to do it lately.

thetechfreak said:
Just trying to get two RPi to forward requests correctly using NDN. Have had some progress but don't get enough time to do it lately.

If you dont mind answering few more questions, Is this your own project to learn new techs? How did you come to know about this ?

Im running a Rock64 with various flavors of debian, having difficulty getting hardware acceleration to work properly.