How to repurpose a dead cell phone's electronics

June 9, 2008 2:58 PM

Know of any good resources "out there" specific to information covering the salvaging, repurposing, and/or cannibalizing of cell phone electronics?

For some strange reason I've had a bit of luck when it comes to locating cellphones that are "dead" or "abandoned". It seems like most of society treats these nifty gadgets like toilet paper. I guess when you can get one free just for signing a 2 year contract it makes it ok to just dump it in the street like everything else?? A horrible excuse if you ask me but lets move on.

Being a pack rat and an amateur solder slinger I've always seen them as a pretty pill box full of possibly useful parts for random projects. So now I have a little collection. Unfortunately finding information on how to salvage these parts and reuse them seems, to me, quite hard to find. So I come to you wonderful folks with the hopes that you'll be able to point me in a direction where I'll be able to satiate my need for making other people's garbage useful. Anything and everything you find will most likely be of some use.

Thanks

posted by monkishies to technology (4 comments total)

Make magazine has something on recycling old cell phones every now and again. Do a quick search on their blog and that's likely to give you a couple leads.

I'm also willing to bet there is info to be had at Lady Ada's Tea Party, but I'm not particularly active there so I'm not 100% sure.
posted by Kid Charlemagne at 5:27 PM on June 9, 2008

I'm afraid you're going to be disappointed. In modern cellphones (anything built in the last ten years) nearly everything is inside one or more ASICs. That stands for Application Specific Integrated Circuit.

For the phones I used to work on, there were two chips which contained nearly everything. One was the RF chip and contained all the analog circuitry for the microwave receiver and transmitter and the other was the digital chip, which contained the CPU, the DSP, all the custom digital circuitry to implement things like the rake receiver, all the flash ROM and all the RAM.

Beyond those, most of the rest of the circuitry was things like surface mount resistors and caps. I think the most complicated circuit outside the ASICs was the charging circuit for the battery. And even that was controlled digitally by the CPU in the digital ASIC.

It isn't possible to take an ASIC apart without destroying it, and it isn't possible for you to "repurpose" it.

Admittedly those phones didn't have very complicated displays. In a modern phone with a color LCD, there's going to be circuitry to drive that, and phones which contain cameras will have circuitry for that too. On the other hand, I wouldn't be surprised if they cope with that by using a third ASIC.

But most of what's in the phone isn't available to you to tinker with.
posted by Steven C. Den Beste at 9:26 PM on June 9, 2008

Seconding SCDB.

SMT parts are just no good for most hobbyists. I do like to take apart PC power supplies, radios, and nearly any other non-super-miniaturized consumer electronic device I can get my hands on. I harvest resistors, crystals, caps, transformers, LED arrays, etc.

There are a couple of possibilities for cell phones, though.

First, that's a nice lithium-ion battery in there, and if it still works, then you already have the power supply (charging brick). That's good for a project right there. Heck, most of them these days will charge on the 5V/1W you get from a PC USB port.

Then there's the screen. If you Google around, you may find others playing around with the screen that came out of your phone. I remember there were a bunch of hacking projects going around a while back with old Nokia monochrome LCDs. This would almost certainly involve a little coding though, so if you're in it strictly for hardware fun, this won't do it.

Finally, most cell phones will have SMT LEDs, and that's pretty much the only SMT component I would bother with, as they're easy to use and a little simpler than most other SMT parts to put in place and solder. Also, there are lots of new devices these days that employ SMT LEDs where a color swap might be fun. WiiMotes spring to mind here.

Anyway, you'll need a good iron, somewhere in the 15-30 watt range. Solder wick is a must, and a solder sucking bulb is great for the non-SMT work.

Soldering tutorials abound online. Electronics tutorials abound online. Projects await you online. Pull MAKE's RSS feed for lots of inspiration.

Cheers.
posted by SlyBevel at 7:18 AM on June 10, 2008

WOW! Thanks again, everyone!

Even though I'm a bit disappointed by some of what I've found out, I'm extremely satisfied by the depth of information that was provided. Please don't take this as a "that's all folks" post! If anyone else wants to chime in with any more nuggets of WIZdom then please do so!

Hasta!
posted by monkishies at 9:58 AM on June 10, 2008