SparkFun Qwiic Quad Relay

The SparkFun Qwiic Quad Relay is a power accessory board designed for switching up to four high-powered devices from your Arduino or any other low-powered microcontroller using I²C. Its four individual relays are each rated to handle up to 5 Amps per channel at 250VAC or 30VDC. Each channel features its own uniquely colored LED and silk labels for easy identification. The Quad Relay also comes with screw terminals for optional connection. Thanks to the Qwiic system, no soldering is required to connect it to your system.

The SparkFun Qwiic Quad Relay is powered by an ATtiny84 that takes various commands to toggle the four relays. The I²C address of the ATtiny84A is software configurable, allowing you to daisy chain over 100 Qwiic Quad Relays if needed. The board also includes a header that breaks out the four I²C lines if you're not using the Qwiic connectors. The barrel jack is rated for wall adapters in the range of 7-12V, but the relay board comes with a jumper on the underside for use with 5V wall adapters.

While the SparkFun Qwiic Quad Relay is designed to handle high voltage, it comes with numerous safety precautions. These include wide traces designed for high amperage, ground isolation between the relay and other circuitry, and a milled out area around the common pin of the relay. Despite these safety features, it's important to note that this is a power accessory best suited for users experienced with and knowledgeable about high AC voltage.

The SparkFun Qwiic Connect System is an ecosystem of I²C sensors, actuators, shields and cables designed to make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector, reducing the required PCB space and ensuring you can't connect it incorrectly due to polarized connections.

The SparkFun Qwiic Quad Relay is equipped with four JZC-11F relays capable of handling 5A at 250VAC or 30VDC. Each relay has its own colored LED and silk labels for easy identification. Safety features include ground pour isolated from relays, an air gap around the common pin on the relays, and large trace width on relay pins far exceeding the peak 5A current. The ATtiny84A allows for I²C commands for toggling individual relays or all the relays at once, and turning all relays off or on. The I²C address is software configurable, and all commands are listed in the example code.

The latest revision of the SparkFun Qwiic Quad Relay includes several updates. These include a normally closed jumper for the power LED, a switching regulator in place of a linear regulator for improved efficiency, and improved circuitry around the relays to resolve an issue where relays on certain boards in v1.0 didn't switch completely when actuated.