The Neo Freerunner is the second generation fully open-source phone being developed by a global community calling itself Openmoko. The phone is physically manufactured by First International Computer Corp. and normally retails for $400. Because the phone is completely open, schematics, netlists, and models are fully available online.
A small hardware bug was found a while back on the A6-revision where a chip was causing interference on the microphone line. So, once the Openmoko community found a fix, FIC started clearing out the existing phones by selling them for just $250. I’ve been looking at these phones for quite some time; I remember when they were first announced and have followed them off-and-on ever since. I decided that I’d buy one and play with it a bit.
The solution to the buzz problem was to create a low-pass filter to eliminate the buzzing sound that the person you’re talking to gets annoyed at. After messing around with the phone’s many available software distributions for several days and cleaning up all the electronics garbage (or at least attempting to) I brought home with me from school, I decided to try my hand at some SMT soldering. Digi-Key shipped with extraordinarily speed as usual and I had my SMT resistors and capacitor in two days.
The instructions mentioned that for some phones, the resistor that would normally be part of the filter was reading zero ohms (i.e. it was a dummy resistor) for most of the phones produced. If so, it would have been necessary to replace that with a real one. I was extremely thankful when I was one of the lucky few with a real resistor… 0402-formfactor resistors are probably about half the size of the ball in a typical ballpoint pen–imagine desoldering that!
Adding the capacitor was a pretty simple task. I simply made a small jumper with some 30-gauge wrapping wire and soldered that onto the anode. Then, I soldered a wire onto the cathode so that I could easily position the anode jumper and solder that onto the board. Finally, after scraping a little bit of the varnish away to get to the ground plane, I removed the temporary cathode wire and soldered the cap down.
Okay, it's a little messy, but I was trying to make the wire as short as possible in order to prevent RF interference.
Yes, that does look like a cold solder joint, but I swear it's not. The joint is indeed pretty secure.
The only issue right now with the phone is the software. While the hardware is pretty much ready to go (except for the buzz problem, which has already been corrected in the upcoming revision), the software is still all over the place. Right now, I’m using SHR, one of the more popular distributions. It’s full of features, but a bit buggy when it comes to WiFi. Also, it seems as though display acceleration isn’t being handled very well… Fingerscrolling can be painfully slow at times.
My mom definitely wasn’t kidding when she saw my phone disassembled with a soldering iron next to it and said “you’re a geek.”
) pictures; here are the best:
