Adafruit
Adafruit Rotary Trinkey - USB NeoPixel Rotary Encoder
The Adafruit Rotary Trinkey is a tiny USB A board built around the ATSAMD21 microcontroller with a footprint for a standard rotary encoder and a built-in Neo...
The Adafruit Rotary Trinkey is a tiny USB A board built around the ATSAMD21 microcontroller with a footprint for a standard rotary encoder and a built-in NeoPixel LED. Plug it into any USB A port on your computer and program it as a volume knob, scroll wheel, zoom control, or any custom rotary input device.
The board supports CircuitPython and Arduino, and over USB it can appear as a serial console, MIDI device, or HID keyboard/mouse — making it incredibly versatile for custom input projects. A capacitive touch pad and reset button round out the feature set.
Key Features
- ATSAMD21E18 Processor – 48 MHz 32-bit Cortex M0+ with 256 KB flash and 32 KB RAM
- USB A Plug – Plugs directly into any computer's USB A port, no cable needed
- Standard Rotary Encoder Footprint – Compatible with any PEC11 or PEC12 style 5-pin rotary encoder (not included)
- NeoPixel LED – Single RGB under-lighting LED for colour feedback
- Capacitive Touch Pad – One additional touch input
- Native USB – Serial, MIDI, and HID (keyboard/mouse) support
- CircuitPython & Arduino – Full support with existing Rotary, NeoPixel, and FreeTouch libraries
Ideal For
- Custom volume knobs and media controllers
- Scroll wheels and zoom controls
- MIDI controllers and music production tools
- Macro input devices and productivity shortcuts
Package Contents
- 1× Adafruit Rotary Trinkey (ATSAMD21, NeoPixel, capacitive touch)
Jargon buster
Plain-language definitions for the technical terms used above.
- CircuitPython
- A beginner-friendly version of Python designed to run directly on microcontroller boards. If a product supports CircuitPython, you can often program it by copying code files onto the board rather than setting up a more complex toolchain.
- encoder
- A device attached to a motor or shaft that reports movement, such as rotation steps or position. In a pump system, an encoder can help measure or control how much the motor has turned, which affects how repeatable the watering amount can be.
- HID
- Human Interface Device is a USB device class used for keyboards, mice, gamepads and similar controls. If a board supports HID over USB, it can act like an input device to a computer without needing a custom driver.
- LED
- A light-emitting diode is a small electronic component that lights up when current flows through it in the correct direction. In this kit, LEDs create the flashing effect, so polarity and correct soldering matter for the project to work.
- microcontroller
- A microcontroller is a small computer on a chip that runs your program and controls connected inputs and outputs. For this product, it is the part that reads buttons and sensors, drives the display and speaker, and communicates over Bluetooth.
- MIDI
- MIDI is a standard way for electronic instruments, controllers, and software to send musical control messages such as notes, velocity, and timing. If a board supports MIDI, it can be triggered from keyboards, drum pads, sequencers, or other music gear rather than only from buttons or code.
- native USB
- Native USB means the microcontroller itself handles USB communication, rather than using a separate USB-to-serial chip. This matters for programming, debugging, and projects that need the board to act directly as a USB device.
- NeoPixel
- A type of addressable LED system where colour data is sent along a single digital data line from one LED or controller to the next. Compatibility matters because the timing and signal format must match for the lights or driver board to respond correctly.
- RAM
- RAM is temporary memory used while a device is running, and its contents are lost when power is removed. A “Run in RAM” mode is useful for testing settings without permanently programming the module, but it may not support every feature.
- RGB
- Short for red, green and blue, usually referring to an LED that can mix those three colours. It matters because controlling an RGB LED teaches how separate outputs combine to create different colours.
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Related Tutorials
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