Homemade Arduino

Homemade Arduino - I put together an Arduino using this link at: http://www.arduino.cc/en/Main/Standalone

The electronics are a little more robust compared to stock Arduino. I plan on using it directly on my 12v electrical on my motorcycle.

Youtube video of the DIY Arduino at work: http://youtu.be/NQDIg8ONCEk

Do you have decoupling capacitors on the under side, if not add them.
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LarryD:
Do you have decoupling capacitors on the under side, if not add them.

Thank you Larry,

I never get replies and my posts die slow deaths falling to the bottom of the list...

Yea, I forgot them... I followed the directions too closely.

Decoupling caps are 0.1uF (100nF) and are usually small and brown.
Add one from VCC to Gnd, AVCC to Gnd, and Aref to Gnd. Do not connect Aref to 5V.
Connect the caps as close to the pin as you can.
Typically there is 4th from the FTDI header DTR to Reset, and a 10K pullup from Reset to Vcc for software generated reset during software downloads.

I plan on using it directly on my 12v electrical on my motorcycle.

I would also recommend you look into using a SMPS for regulation.
see eBay link.
Here

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LarryD:
I would also recommend you look into using a SMPS for regulation.
see eBay link.
Here

.

That defeats the "homemade" thread of thread.

OK
You will need 878,674 transistors to replace the AMTEGA328.

:wink:

LarryD:
OK
You will need 878,674 transistors to replace the AMTEGA328.

:wink:

Well… I really want to work towards sourced components and possibly making a PCB with the microcontroller placed on board. I honestly do not wish to use 878k transistors for any project.

Kidding aside, I don't believe there is too big of an argument between a SMPS and using a three terminal voltage regulator. I have stopped using 7805s in most of the of my projects in lieu of SMPS as linked to.

A SMPS has effientcy up to 90%.

If you use a 7805, with 12v input at let's say 500ma, you will need to heat sink the TO220.
(12 - 5)*.5 = 3.5 watts "ouch".
At 1 amp that's 7 Watts!

I do find these interesting. I would include 2 of them on a homemade Arduino, one for 5V and one for 3V3.

And one of these:
http://www.tinyosshop.com/index.php?route=product/product&product_id=600
I think it would be interesting to arrange right angle male and female headers on the main board which has the ATmega328P, so these modules plug together to make a complete Arduino. A modular Arduino; kind of like a Sparkfun ProtoSnap Pro Mini board, except instead of snapping apart, plug the modules together.
Maybe even include one of these on the board:

If you could cram it all into the footprint of an Arduino, you would have a super-Arduino.

dmjlambert:
If you could cram it all into the footprint of an Arduino, you would have a super-Arduino.

I agree DMJ, I thought it would be nice to have the same footprint of a 3.3v & 5.0v logic converter as well. You could use more I2C circuits without longterm voltage issues. I like the term "super-arduino".

Also, I am not in a big push to put programming on the board yet. I want to move toward a manufactured product with progamming one time. I would use pads and "pogo" pins to program.

My '1284P BobuinoII can take a switching regulator in place of fixed 5V regulator and has lots of super stuff on it.

  • 1284P with 16K SRAM, 128K Flash, 4K EEPROM, dual hardware serial ports, 32 IO.
  • onboard or off board USB Adapter
  • RS232 buffer available for the 3nd port
  • 3.3V regulator to power fully buffered SD card socket.
  • extra buffers from cd74HC4050 and 74HC125 are brought out to pads
  • DS1307 RTC with battery backup
  • power, Gnd, signal available at all IO locations next to the female headers
  • prototype area for a chip or two, long enough to plug in a 433 MHz receiver.
  • screw terminal option
  • and probably some other stuff I missed.
    Cross Roads Electronics

Here is another option:

http://www.mcmelectronics.com/product/124-10255?scode=GS401&utm_medium=cse&utm_source=google&utm_campaign=google&catargetid=530004080000291407&cadevice=c&gclid=Cj0KEQiApruyBRCFqoDu1pbk9rkBEiQAF8EFdXnRh9O4NqgGdPPWiQFZZ1V_dGfqL4cdO-pQ8L6js2oaAm2C8P8HAQ

I dunno. By the time you're willing to use a TO220-sized regulator, a lot of the motivation for using a switching power supply disappears, especially for that 5V->3.3V step...
The TI NanoModules are neat, too. http://www.ti.com/product/lmz21700

I should be very susprised if a switchmode regulator was more efficient thatn a series regulator in reducing 5 V to 3.3 V. Now of course, it does make sense to regulate a higher voltage - 12 V or so - directly to 3.3 V with a switchmode regulator if you do not mind paying 7 times the component cost for that second regulator.

LarryD:
http://www.mcmelectronics.com/product/124-10255?scode=GS401&utm_medium=cse&utm_source=google&utm_campaign=google&catargetid=530004080000291407&cadevice=c&gclid=Cj0KEQiApruyBRCFqoDu1pbk9rkBEiQAF8EFdXnRh9O4NqgGdPPWiQFZZ1V_dGfqL4cdO-pQ8L6js2oaAm2C8P8HAQ

What a ridiculous link!

Did you mean http://www.mcmelectronics.com/product/124-10255 ?

lol. it took me a while to realize everything after the '?' can be left off.

while smps type are more efficient and op is dropping from 12v still makes little sense at the current levels involved. specially when you consider they often have orders of magnitude more noise compared to linear and 4 dollars (double that with s&h) vs 4 cents. of course some get enormous pleasure out of spending more than necessary. strange how people can latch onto an idea...

I wonder what’s the deal not selling to the UK on this item?

I use linear voltage regulators all the time and I am a fan of the 7805. Sure, it's not power efficient, but it doesn't have as much ripple as a homebrew beginner SMPS can have.

DIY-ing a discrete SMPS is not for beginners. Not only it is more prone to noise if built on a breadboard or perf board, but care must be taken with component selection and placement. Besides, it usually uses more parts. Even using a switch mode power regulator IC (such as the popular LM2596T-ADJ) requires some knowledge and good design practices.

Therefore, for most beginners or people without a some knowledge in electronics, I suggest just to go ahead and use a linear voltage regulators and be happy! Learn one thing at a time. The OP already did a good job getting his homemade board to work, and that's a lot more than many beginners have accomplished.

To the OP, I just suggest he adds a few bypass caps: before and after the voltage regulator and close to the Atmega328.

Why should you use bypass caps?

Paul__B:
What a ridiculous link!

There are those that insist on giving 4 compliments every day before the sun sets.

There are those that do the opposite . . .
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CrossRoads:
Decoupling caps are 0.1uF (100nF) and are usually small and brown.
Add one from VCC to Gnd, AVCC to Gnd, and Aref to Gnd. Do not connect Aref to 5V.
Connect the caps as close to the pin as you can.
Typically there is 4th from the FTDI header DTR to Reset, and a 10K pullup from Reset to Vcc for software generated reset during software downloads.

Thank you CrossRoads,

I implemented all of your suggestions except one. I did not add a cap to the FTDI header because I am just popping ATMega328 chips like Nintendo cartridges. I made a new board using 5cm x 7cm proto PCB and added the pin headers this time. I loaded up my Muybridge animation I wrote and posted on another thread.

Video of Homemade Arduino with horse animation: http://youtu.be/LmUHsK3exoU