Build the electronic parts

SCHEMATICS

BILL OF MATERIALS

• Raspberry Pi 2 : ~ 39€
• Sparkfun 7-segment display : ~ 12 €
• USB DAC PCM2704 : ~ 6,50 €
• PCB SD card reader : ~ 1 €
• Sparkfun microUSB breakout : ~ 2 €
• 3.5mm stereo jack socket
• USB A connector (for PCB)
• 2 * Digitast switch
• MIDI socket
• veroboard / perfboard
• female-female Dupont cables
• pin headers
• 3 resistors: 1 x 220Ω, 1 x 10 KΩ, 1 x 1 KΩ, and 1 diode: 1N4148
• 1 optoisolator 6N138