Interface a 4-Channel Relay with Raspberry Pi 4, 4 channel relay with rpi4, relay raspberry pi 4, raspberry pi 4 relay, relay rpi4, rpi4 relay We learned in the previous tutorial how to connect a joystick to a Raspberry Pi 4 using an mcp3008 and an op-amp IC, the LM324A. For each of the interface methods we studied, we created a python script allowing us to interact with the circuit. This tutorial will show you how to connect a 4-channel r ...