For the past two days I’ve been building up the Dust prototype circuit.
So far I’ve gotten away with entirely found parts… This is fine for the breadboard, but for our final wearable version, we’ll need to reduce the size significantly.
- Relays are Omron G5A and an OEG 105D. These are much too big. I would prefer Omron G6H (high density)
- TIP-120 Darlington transistors could be replaced by 2N3904 transistors (or maybe there are SMD transistors). I originally wanted to avoid using relays to drive the MP3 player, but our tests with transistor-only circuits were unsuccessful.
- The Coby MP3 player is small, but the Sakura (from the designer of the MAKE DaisyMp3) is smaller — and open source.
Remaining tasks:
- Writing the Arduino code
- Testing the LM386-based amplifier