Workshop 88 member [Jim] got his hands on a couple of SanDisk Sansa Clip+ MP3 recorder/players from Woot, and was anxious to see what he could do with them.

The first order of business was to install RockBox, an open source hardware package built for a wide range of MP3 players. He was impressed with how robust the firmware was, though he thought the Sansa’s built-in microphone could use a bit of upgrading. Acting on a tip from a fellow square dance enthusiast, he disassembled one to see how he might add an external audio input.

He pried the existing mic apart, and desoldered it from the motherboard, installing a small capacitor and resistor in its place. He extended some wires through the case, then powered up the unit to make sure it was still alive and well. Since things still looked good, [Jim] put some audio on the Sansa’s new inputs and sure enough it recorded the audio without a hitch.

He says that his initial guesses for the capacitor and resistor values were pretty decent, though with a bit of tweaking he should be able to get exactly the recording levels he was looking for. Not bad for a $20 audio recorder!

One man’s useless machine is another man’s treasure… or something. [Matt] shared a link to his MP3 gr3nade in the comments of our useless machines post. The project took a decomissioned hand grenade and shoehorned an MP3 player into it. His decision to locate the headphone jack where the safety pin goes is a nice touch.

This reminds us of the boss from a previous job who had a chrome plated hand grenade on his desk.  Now that was a useless object (and a useless boss). This project actually does something, but are you really going to ride around on the subway rockin’ out to the Bee Gees while holding a hand grenade?