Saturday, November 28, 2009

Minimal Arduino?

I prefer breadboard-friendly Arduino-compatible boards like Boarduino and iDuino, but I keep wanting functionality people have built into shields like Adafruit's Motor Shield and Batsocks' TellyMate Shield.

All I want in an Arduino:
  • ATmega328
  • FTDI programming header
  • Arduino "form factor" with odd D7/D8 spacing and standoff holes
Sorting my Arduino-compatible board spreadsheet first by price, then by form factor, it seems the lowest price for a shield-compatible board is ~$17 for a serial Freeduino, compared to ~$10 for a Dorkboard, though the latter comes with an ATmega168, not a 328.

Necessary items:
  • microcontroller: ATmega328, socket, capacitor
  • clock: oscillator and 2 caps, or a resonator
  • reset: 90-degree (side) button, 10K resistor
  • FTDI cable interface: 6-pin header, capacitor
  • Power: Barrel connector, 2-pin header
Extra interface header pin pads:
  • icsp (2x3)
  • i2c (4)
  • spi (6) (nah)
Simple extras, parts not provided:
  • Power indicator: LED, 1K resistor
  • TX/RX indicators: 2 more LEDs, 2 more 1K resistors
  • Power regulation: 7805, 2 capacitors, jumper
  • Diode to prevent inverted power hookup
I'm traveling for the next month so this will be a fun little layout project, perhaps as a way to learn kicad (as opposed to EAGLE, which I currently use) and to explore board house pricing and specs. The goal is to be able to produce a $10 kit (cost), which may be possible given how many goodies SparkFun includes in their $20 Arduino Pro 328.

Update 12/29: I got a single-sided board laid out with just four jumpers, and I'll tear it up and redo it with the programming header where I want it, jumping TX and RX across the board. The files for the "Severino" single-sided board helped me figure out the routing.


  1. This came in very handy as my area of study is motor controllers.

  2. Relly instresting layout concepts, I cant wait for there to be a board to fit inside the shield footprint, and it looks like the 2 sided board will still be simple enough for people to make at home once the ICSP issues are sorted.

    Cant wait till you post the Eagle files!