Parts List

• Arduino microcontroller
• MakerShield kit
• Q1: 2N3904 or S9013 NPN transistor
• R1: 10KΩ resistor (brown, black, orange stripes)
• R2: 1KΩ resistor (brown, black, red stripes)
• SPKR1: mini 8Ω speaker
• C1: 100 uF electrolytic capacitor
• PC1: photocell

Figure 12-1. The Theremin