Adafruit I2C Stemma QT Rotary Encoder Breakout with Encoder

Incorporating rotary encoders into your project can be quite a challenge due to the need for timers, interrupts, and debouncing. Unlike potentiometers, these encoders have a full rotation range and often come with tactile feedback in the form of detents.

This Stemma QT breakout eliminates the frustration of manually tracking pulses and pins by featuring a pre-soldered rotary encoder with a push-switch. Additionally, the onboard microcontroller is programmed with our seesaw firmware to accurately save the incremental value for easy querying over I2C. Simply plug it in using a Stemma QT cable for instant rotary functionality with any compatible microcontroller, from an Arduino UNO to a Raspberry Pi.

This version of the board has a rotary encoder already soldered in, for instant gratification. You'll still need to get a knob if you desire one, we have lots in stock. Make sure its a D-shaft, or set-screw type not T18. If you want your own encoder, you can grab our not-soldered-in version here.

You can use our Arduino library to control and read data with any compatible microcontroller. We also have CircuitPython/Python code for use with computers or single-board Linux boards.

It's also easy to add this breakout to a breadboard - with six 0.1"-spaced breakout pads. Power with 3 to 5V DC and then use 3 or 5V logic I2C data. The INT pin can be configured to pulse low whenever rotation or push-buttoning is detected so you do not have to spam-read the I2C port to detect motion.

There's a NeoPixel on board, that can display any color you like. It's also controlled over I2C for additional visual feedback or keep it off if you like. On the back, there's a green power LED as well as a red INT LED that, if the interrupt is configured, will blink when the interrupt fires.

Using the three onboard address jumpers, you can connect up to 8 of these rotary encoders on a single I2C port. The first one will be at address 0x36, the last one at 0x3D when all three jumpers are soldered closed.

To keep the board nice and compact, only 1" x 1" we made the footprint for the rotary encoder at a 45-degree angle. Since it rotates around freely there's no need for it to be at a 90-degree angle to the PCB. Each order comes with one assembled and tested PCB breakout with encoder and a small piece of header.

To get you going fast, we spun up a custom-made PCB with the seesaw chip and all supporting circuitry, in the STEMMA QT form factor, making them easy to interface with. The STEMMA QT connectors on either side are compatible with the SparkFun Qwiic I2C connectors. This allows you to make solderless connections between your development board and the rotary encoder or to chain them with a wide range of other sensors and accessories using a compatible cable. QT Cable is not included, but the shop has a variety.