SparkFun Qwiic Quad Relay

The SparkFun Qwiic Quad Relay is a unique power accessory board that has been designed for switching not one but four high powered devices from your Arduino or another low powered microcontroller using I2C. Taking a look at the board, the Quad Relay has four individual relays rated up to 5 Amps per channel at 250VAC or 30VDC. Each channel also has its own uniquely colored LED, silk for easy identification, and screw terminals for optional connection. Utilizing our handy Qwiic system, no soldering is required to connect it to the rest of your system!

At the heart of the SparkFun Qwiic Quad Relay is an ATtiny84 that takes various commands to toggle the four relays. The I2C address of the ATtiny84A is software configurable so if you had the desire and power, you could daisy chain over 100 Qwiic Quad Relays. There is also a header that breaks out the four I2C lines if you're not taking advantage of the Qwiic connectors. And last up, the barrel jack is rated for wall adapters in the range 7-15V but we have equipped this relay board with a jumper on the underside of the board if you want to use wall adapters at 5V.

Messing with such high voltage is dangerous! We've included many safety precautions onto the PCB including, 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. However, with all the safety precautions included with the SparkFun Qwiic Quad Relay, this is still a power accessory for users who are experienced around, and knowledgeable about high AC voltage. If that's not quite your jam, that's okay! Check out the IoT Power Relay, instead, to start learning how to use power relays easily.

NOTE: The I2C address of the Quad Relay is 0x6D and is jumper selectable to 0x6C (software-configurable to any address). A multiplexer/Mux is required to communicate to multiple Quad Relay sensors on a single bus. If you need to use more than one Quad Relay sensor consider using the Qwiic Mux Breakout.

Important: You can only use up to four relays when using our 9V/650mA Wall Adapter but the onboard regulator gets really hot. If you close the jumper on the underside and pair it with our 5V/2A Wall Adapter than you sidestep the voltage regulator and the heating issue.

The SparkFun Qwiic Connect System is an ecosystem of I2C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.

  • Four JZC-11F Relays
    • 5A at 250VAC, 30VDC
    • Each relay has its own colored LED and silk labels for easy identification.
  • Safey Features
    • Ground pour isolated from relays.
    • Air gap around common pin on the relays.
    • Large trace width on relay pins far exceeding the peak 5A current.
  • ATtiny84A
    • I2C commands for toggling individual relays or all the relays at once.
    • I2C commands for turning all relays off or on.
    • Two I2C addresses: 0x6D, 0x6C
    • I2C address is software configurable.
    • All commands are listed in the example code.
  • Screw Terminals
    • 26-14 Gauge AWG wire
  • Power
    • Max Current Draw ~250mA
    • Dropout Voltage is ~7.4V

SparkFun Qwiic Quad Relay Product Help and Resources

Qwiic Quad Relay Hookup Guide

January 3, 2019

SparkFun’s Qwiic Quad Relay is a product designed for switching not one but four high powered devices from your Arduino or other low powered microcontroller using I2C.

Core Skill: DIY

Whether it's for assembling a kit, hacking an enclosure, or creating your own parts; the DIY skill is all about knowing how to use tools and the techniques associated with them.


Skill Level: Noob - Basic assembly is required. You may need to provide your own basic tools like a screwdriver, hammer or scissors. Power tools or custom parts are not required. Instructions will be included and easy to follow. Sewing may be required, but only with included patterns.
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Core Skill: Programming

If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.

2 Programming

Skill Level: Rookie - You will need a better fundamental understand of what code is, and how it works. You will be using beginner-level software and development tools like Arduino. You will be dealing directly with code, but numerous examples and libraries are available. Sensors or shields will communicate with serial or TTL.
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Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

4 Electrical Prototyping

Skill Level: Experienced - You will need to consult a datasheet for calculations to determine a components output format, linearity, and do a little math to get what you need. You will be using a datasheet or schematic beyond basic pinouts.
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Customer Reviews

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Rock solid

So I'm working on a project at my job, enhancing a ride-on toy car. The thing has a gamepad remote control, so I thought, "Hey, why don't I use this as part of the tablet control?" I tore down the gamepad and got to probing with a multimeter. Good news: all the buttons and levers are simple momentary switches. Bad news: the voltages were all over the place, ranging from the usual 3.3V to a really weird 0.38V. I'd originally planned on using plain old BJTs to replace the switches, but I wasn't confident that it would do the job without destroying the black box ICs on the board.

Enter the original electronic switch, AKA the relay. I'm familiar with these things: way back in my freshman electrical engineering class, our semester project was to create a dead simple robot using only passives, transistors, and relays. Back then, Arduino didn't even exist except possibly as a seed of an idea in a certain Italian's mind. Compared to that project, hooking up this board to a SparkFun Thing Dev board was a breeze. Sure, I needed to look up which pins were used for I2C and solder those to the Qwiic adapter, but once that was sorted, this thing probably became the most reliable part of the build. Press button in app, relay clicks. No worrying about flyback current, no need to convert voltage into something the relay can use, this board does it all for you. Best of all, it worked as a replacement for the simple gamepad momentary switches at all voltages.

Now, there was a mishap somewhere between packing and shipping (I blame the FedEx distribution guys who throw everything) where one of these boards wound up with an optoisolator ripped off the board (complete with a solder pad and trace) and embedded in a shattered barrel jack. I was equal parts shocked and impressed at the damage. The good fellas at SparkFun were quick to ship a replacement board, and I think I'll try to repair the damaged board with another optoisolator and some magnet wire. Good thing the schematic is readily available.