May 12, 2013

"Ayrduino" Single-Sided Arduino Clone

I'm teaching "Electronics for Scientists" this semester, and I wanted to allow each student to have their own Arduino to play with for microcontroller lab exercises and possibly use for their final projects. The Arduino is not very expensive at roughly $30 per, but they add up quickly when you have a whole class of students needing one each. I'd been buying enough electronics equipment over the course of the semester that my department chair was showing an involuntary tic any time I knocked on his office door... So I built my own. They are a stripped-down variant of the Duemilanove.

  • Standard Arduino form-factor and mount-points.
  • Accepts standard Arduino shields.
  • Single-sided board, easy to make with toner-transfer method. 
  • 16MHz ATmega328.
  • No SMT parts.
  • On-board 5V regulation.
  • Screw-terminal power-in connector, rather than barrel jack.
  • Pin-13 LED.
  • Lacks on-board USB-Serial conversion, so programming requires an FTDI cable.
  • No 3.3V regulator.
  • This is as detailed a board as I ever want to make using toner-transfer.  
  • No TX/RX LEDs.
  • No ISP connector.
  • Three component-side jumpers. Couldn't quite get all traces on the back side!
None of these down-sides are significant for this application. The requirement of FTDI cable is inconvenient, sometimes, but I have 3-4 of them in the lab and students share them without too much squabbling.

My grader, Lena, did most of the drilling and soldering work. She's graduating next week, and I'll miss her, but the graduate program in Nuclear Engineering at University of New Mexico is going to be thrilled.

If you want to make your own single-sided Arduino variant, and this set of pros/cons is acceptable to you, here are the EAGLE files. One of the smart-asses in the electronics class immediately dubbed it the "Ayrduino"...

Note: the Arduino design, on which this is based, is licensed under the Creative Commons Attribution-ShareAlike 2.5 license; so this is available under that same license as well.

Parts list:
  • ATmega328P-PU (1)
  • 16MHz crystal (1)
  • 22 pF cap, ceramic (2)
  • Button, momentary tactile switch (1)
  • Angled header, 6-pin male (1) 
  • 0.1µF cap, ceramic (5)
  • Red LED (1)
  • Green LED (1)
  • 1N4001 diode (1)
  • 2-position screw terminal (1)
  • 7805 regulator (1)
  • 10kΩ resistor (1)
  • 510Ω resistor (2)
  • 47µF Al. Elect. cap (2) (short ones to fit under shield boards)
  • Female headers, 8-pin (2) (optional)
  • Female headers, 6-pin (2) (optional)
  • 28-pin IC socket (1) OR 14-pin IC socket (2) (optional)
  • Three short jumper wires
  • Single-sided PC board, 0.032" 1/2oz Cu.
You can cut 11 of these from one 8x10 sheet of PC board if you do it just right.


  1. Just a thought:
    Ever had a look at
    Get one clone for about $9 free shipping.
    AFAIR even cheaper in bulks of 10 or more.

    1. Or $5.30 for an Uno clone... But where's the fun of that?

  2. Just a question; where to get the firmware for the uController?

  3. Use the "burn bootloader" menu option (under tools) in the Arduino IDE. You'll have to set up an SPI connection to the chip... I did it using a separate breadboard and another Arduino, as described on the pages; but you could use the same method (with slight modification) with the chip in this board, just wiring to the appropriate pins. See this page:

    1. Dear Dr. Ayars,
      Thank you kindly for the information and the layout of the uController unit. The link to the Eagle schematic and layout file doesn't seem to work i found out in the first instance, so i took your .png-file as example to re-draw the whole pcb in a (for me more familiar format) the Sprint layout pcb program. The program is ideal for these kind of situations because one can an "underlay" the original .png or whatever file picture format and simple scale up or down in the Sprint program and start a "following the tracks" action to draw an actual usable layout. After checking you simple remove the original .png file and print it on a transparant sheet to photograpically produce the pcb (uv-exposure, develop and etch).
      So i do have an exact copy of the pcb layout, next is to make it when i've got some time left.
      Myself i'am relative new to this Arduino e.o. systems to design and construct with, so i've lots of reading to do.

      Yes, i do like to make things myself, mostly electronics, sometime electromechanical. It's a hobby for me. Radios have also my intrest, specially the old ones with battery tubes, like your famous Armstrong receiver, medium wave regenerative. Fantastic one how with so less parts, so very good receiving results can be achieved.
      By the way, i'am from the Netherlands, Europe from a little town called Wassenaar near the Northsee (Google Earth will show you).

      After playing around on the server i've discovered (big word, for such a small thing actually), that the Eagle-files are under: available.
      Wish i've known that before a start re-drawing the pcb... :-))
      One directory/map up in your system all the other files are to be found, sorry for snooping!
      That's it for now.
      Thank you again and with kind regards,
      Hans Venema

    2. Sorry for the bad link, and I've fixed it now. Other than that, I hope you found it helpful!

    3. This single-sided design is brilliant !!! Thank you very much for making it available. Your boards are beautifully made. I am currently learning about the CadSoft EAGLE software. I just finished making a new Perfboard*uino for a Robot Toy I am trying to make, in order to learn Electronics, microcontrollers, robots, and toys. Once again, thank you very much !!!

  4. hi.thanks for this great design. i found all the parts except that 510 ohm resistance. locally i found 560 ohm. will it work? and also got blank atmega328 p here. so, do i need bootloader already installed in that ic? or is it possible to load bootloader on blank ic from this board? note that i don't have any other arduino or avr. this is my first arduino board. please sir. help!!! thanks.

    1. 560 Ohms will work fine: those resistors are just current-limiting resistance for the LEDs.

      You WILL need a way of loading the bootloader onto your blank ATmega328p, though, and you can't do it with this circuit alone. You will need a programmer or another Arduino, or a local friend with a programmer or another Arduino. If your first Arduino project is building an Arduino, that's tough! The best advice I can give you is to get an Arduino and gain some experience with simpler projects before tackling this.