Quantity   Component name
1 × Raspberry Pi (Plus or 2) needs 40 pin GPIO connector
26 × Toggle switches
12 × 390 Ohm resistors
26 × 4148 Diodes
1 × UDN2981A (optional) Interface and IO ICs / Peripheral Drivers and Actuators
1 × PCB Designed in Kicad/Open source hardware design
89 × LEDs (5mm, High Brightness) Electronic Components / Misc. Electronic Components
3 × 1K Ohm Resistors
1 × 2*20 pin header for mounting the Raspberyr Pi You need a specific extra-tall header available at Adafruit