Quantity   Component name
1 × Wooden base - see instructions 2 inch thick 8 inch diameter hardwood bowl blank from woodworking store.
1 × Center mass - 3 inch chromium steel ball. Available on Amazon and eBay. See instructions.
3 × Piezo crystal microphone or buzzer elements - see instructions Available on Amazon and eBay.
1 × Assembled 3 channel charge amplifier circuit board - see instructions Pad2Pad, per custom specs- schematic & bill of materials free on request
3 × Texas Instruments LMC662 femtoampere op amplifier And passive surface mount componetns - from Digikey. See Pad2Pad BOM.
3 × Arduino Yun microcontroller Linux processor for networking and ARM processor for Arduino code
3 × Magnetic door stops or tripod head - see instructions Available at Lowe's and Home Depot stores
1 × Real time clock module Board and Arduino library per Adafruit.com
1 × Enclosure - Styrofoam cooler or glasss cloche -see instructions