David Mellis from the MIT Media Lab has been designing and refining his DIY cellphone, one that you can build yourself from his open source design files and code. A “difficult, but potentially do-able project,” the phone has the basic features that you’d expect: you can make and receive calls and text messages and it has a phone book for storing numbers. To coincide with CES, we got an update from David on his homebrew consumer electronics device.
What was the biggest design challenge?
Balancing the desire to make a functional phone while keeping it as easy as possible to assemble by hand. Mostly, this was a question of sourcing the right components: parts small enough to fit into a reasonable overall size but still big enough to solder manually. For example, I was lucky that the GSM module on the Arduino GSM shield (the Quectel M10) was both fairly small but with reasonably big solder joints — unlike many GSM modules with 0.5mm pitch connectors. Finding a small and robust screen was also a challenge: the LCD I used initially would break after a month or so of use. The LED matrix I’m using now has been fairly stable, but only shows eight characters. Similarly, I managed to find a nice small speaker, but the audio quality isn’t amazing. In general, there’s been a lot of tradeoffs: balancing functionality against ease-of-assembly. This problem is a lot harder when you’re trying to make something that you’re going to carry in your pocket every day.
What’s the next feature or improvement that you would implement?
I’m less interested in adding specific improvements to the phone itself than in exploring other ways to help people make their own devices. For example, I’m working on a GSM module that’s effectively a cellphone and an Arduino in one, so people can build their own cellphone interface or form factor. I’d also like to find ways to make PCB design appealing to new groups of people; making simple boards doesn’t seem that hard, so I’m curious to see how we might be able to place it in a design context rather than an engineering one. Finally, I’m also interested in finding ways to get the phone itself out to more people, whether by having them build it themselves or otherwise distributing it.