Quantity   Component name
1 × Pi Zero W E.g. https://www.adafruit.com/product/3400
5 × White ping pong balls These are used to make a big target for the lasers, easing in the laser aiming process.
1 × TIP120 Power Darlington Transistor For switching the laser diodes on/off; other transistors would work as well, just make sure they can dissipate about 1 W. E.g. https://www.adafruit.com/product/976
2 × Speaker wire (less than a few feet) For connecting the two speakers to the Pi Stereo Bonnet
1 × MCP3008 - 8-Channel 10-Bit ADC With SPI Interface Facilitates reading of the resistance of the photoresistor. E.g. https://www.adafruit.com/product/856
2 × Simple push button One for calibrating the strings, and one for power on/off
1 × Break-away 0.1" 2x20-pin Strip Dual Male Header Adds pins to the Raspberry Pi Zero W; enables connection to the Pi Stereo Bonnet. E.g. https://www.adafruit.com/product/2822
2 × Half-size breadboard For prototyping circuits, e.g. https://www.adafruit.com/product/64. Can be replaced with a solderable breadboard, if something more permanent desired
5 × Various resistors (to be updated with values)
5 × Various photoresistors (to be updated with values)
5 × 5 V current-limited red laser diodes (~5 mW) Must be internally current-limited for stable output, and optically collimated with a small lens to form a dot (avoid the ones that are focused to a line). E.g. you can get a ten pack of these here: https://www.amazon.com/gp/product/B00R73MC1S
1 × 2.4A or greater, 5 V well-stabilized power supply E.g. https://www.adafruit.com/product/1995 Or, E.g. you can also use a *nice* 2.4A Android phone charger.
1 × Mini HDMI to HDMI (jack or cable) For connecting Pi zero to a display with HDMI. E.g. https://www.adafruit.com/product/2775 or https://www.adafruit.com/product/2819
1 × USB OTG Host Cable - MicroB OTG male to A female For connecting Raspberry Pi zero to a keyboard/mouse. E.g. https://www.adafruit.com/product/1099
1 × Black spray paint (e.g. Rustoleum)
1 × Drill and small bit For drilling a hole in the ping-pong balls
1 × CNC cutter Cuts the wooden laser harp frame
2 × Unenclosed 3 W, 4 ohm speakers Unpowered, unenclosed speakers to be driven by the Pi Stereo Bonnet. E.g. https://www.adafruit.com/product/1314
1 × Several female-to-male breadboard wires For protoyping circuits and connecting to the Pi bonnet pins. E.g. https://www.adafruit.com/product/1954
1 × Several male-to-male breadboard wires For prototyping circuits.
1 × Adafruit I2S 3W Stereo Speaker Bonnet for Raspberry Pi - Mini Kit For connecting and powering speakers from the Pi. E.g. https://www.adafruit.com/product/3346