Cell phones (like this and this) are turning out to be a reasonably popular open source project. It makes sense when someone points it out. They are pretty much the Swiss Army knife of the digital world. More importantly, they are useful and versatile but they don’t require any real hardware hacking. That’s important since most of the people doing open source work are comfortable with code and soldering irons…not wrenches.
Here’s an outline of the open source hardware necessary to physically assemble your own touchscreen phone. Zach Wick grabbed all of this stuff off-the-shelf (his or someone else’s).
The Arduino Uno uses an ATmega328 microcontroller, which will serve as the brains of the phone.
The LiquidWare TouchShield Slide is a 340×240 resistive touchscreen that fits exactly on top of the Arduino Uno. This will be the user interface for the phone.
The LiquidWare Lithium Backpack also neatly fits onto the Arduino Uno. It comes in several different capacities which seem to deliver 9, 15 or 29 hours of standby (Arduino just idling).
This SM5100B GSM module, provided by Sparkfun, is technically just the green board, but since it needs things like a SIM socket to actually work it’s pretty useless without the red evaluation board (or at least just the SIM breakout board).
When we put all of that together…
- Arduino Uno – $35 at RadioShack, $30 at Adafruit, $17 if you take your chances with Ebay knockoffs
- TouchShield Slide – $180 at Jameco, $175 at LiquidWare
- Lithium Backpack – $48 at LiquidWare, $35 at Liquid Ware
- SM5100B (only) – $68 at Amazon (CanaKit), $60 at Sparkfun, $50 at CuteDigi,
…we get an optimistic price of $277, an expected price of $308 and a pessimistic price of $331. If we use the standard project management SWAG formula [(1x+4y+1z)/6], plus 20% for the unexpected, the price to put all of this hardware together should be around $368 (Zack estimated $340). This project seem to be quite do-able while still being cost competitive with commercial solutions (a new phone will usually cost you a couple or three hundred bucks).
Wick has a concise post in which he explains why he wants to build his own phone. It seems to be a combination of 1) geek-cred and 2) true ownership of the tool and the knowledge necessary to build it and make it work.