Many moons ago I built a MIDI to Relay kit that allowed me to control all kinds of small motors and solenoids via MIDI from a keyboard or sequencer. Ever since then, I’ve had a soft spot for kits that add relays to microcontrollers. The PicoRelay8 board is supplied fully assembled and allows you to nearly instantly add 8 relays to a Raspberry Pi Pico or Pico W.

The 8 relays on board are rated to switch devices drawing up to 10A at 28V DC. While that means it isn’t mains power rated it still is enough power to run some pretty large devices. The relays are each connected to a GPIO pin on the Pico and pulling the relevant pin high results in the relay contacts closing allowing power to flow. Returning the GPIO pin to a low state opens the relay turning off the attached circuit. The relays look like quality components; they were in part selected as they have Silver Tin Oxide contacts for better switching of high inrush currents which we’ve certainly seen using relays with DC motors.

There’s a note on the product listing that’s worth repeating: if all 8 of the relays are energised at the same time, then the Pico power supply must be able to deliver over 500mA. With Bluetooth support hopefully coming soon to the Pico W we can imagine all kinds of fun controlling these relays via our phone!