Qwiic Relay

Have you ever wanted to control something powerful? Have you ever needed to turn on/off a high power device from your Arduino? Now you can with the Qwiic Relay! This device allows you to control large power loads with simple I²C commands. The Qwiic Relay is perfect for large inductive loads like DC motors.

The Qwiic Relay comes with a default I²C address of 0x18 but can be changed with a simple command allowing you to control over 100 Qwiic Relays on a single bus!¹ In addition, there is an address jumper on the back of the board. Closing this jumper with solder will change the address to 0x19.

The Qwiic Relay comes fully assembled and uses the simple Qwiic interface. No soldering, no voltage translation, no figuring out which pin is SDA or SCL, just plug and go!

This newest version of the Qwiic Relay includes many additional safety features. The ground isolation between the load and the low voltage control has been increased and an air-gap has been added around the common pin. The traces between the relay and the NC/NO/COM terminals have been doubled to increase the maximum current to 5.5 amps at 240 VAC.

Note: Not comfortable playing with high voltage AC? That's understandable. Please consider using the IoT Power Relay. It's not I²C but the IoT Power Relay contains shielding to prevent accidental shock.

Footnote 1: Toggling lots of relays on a 3.3V bus can cause voltage spikes. An external power supply will be required.


Documents:

 

• Qwiic Relay Schematic
• Example Sketches showing how to control the relay on and off, get the status of the relay, find the firmware version, and change the I2C address via software can be obtained here
• Eagle Files
• Firmware for the ATtiny85
• Check the repo for the latest firmware and design files