Watch a demo video to get a better idea of what I mean, or listen to some improvisations: 3 2 1.
Step 1: Materials
- Soldering iron + solder
- Hot glue gun + glue
- Wire Cutter
- 4093 (Quad, 2-input Schmitt trigger NAND gate)
- 1/8" stereo miniplug connector
- 9 V battery connector
- Small capacitors (I used 220 pF monolothic capacitors)
- Single sided copper clad
- Conductive foam (comes with microcontrollers and DIP chips)
- Power supply (for watching current draw)
- Sound system or headphones
Step 2: Make FSRs
Plusea makes some really cool DIY FSRs, but I used my own style, because I don't have the same materials available. For Plusea's FSRs, you're working with around 200 ohms - 200 kiloohms max. For mine, you're working with 5-15 megaohms max. Commercial FSRs are in a similar range (e.g., this one is around 20 megaohms without a load). This maximum resistance is important to keep in mind when you're selecting capacitors.