Noisemaker board

The solenoids and the 9v battery connect to this board, which is connected in turn to the Primary HAT. This allows the Pi to send signals for the solenoids to fire, while isolating the Pi from the 9v battery, which is needed for the solenoids but would fry the Pi.

Components

• Perf board (16 x 10 holes minimum)
• 2 x TIP120 Darlington transistor
• 2 x diode
• 2 x 1kΩ resistor
• 3 pin female JST connector

Circuit Diagram

Photos

The below circuit was made with two spare ports (so would required two more of every component apart from the Perf board, and a 5 pin jst)