The Proximity Trinkey is a tiny board with a few fancy features. This page takes you on a tiny tour!

The PDF of this pinout image is available here.

USB Connector

On one end of the Proximity Trinkey is the USB connector. Simply plug it into any USB A port on your laptop or computer, NeoPixel-and-sensor-side-up, to get started!

Proximity Sensor

The APDS9960 proximity sensor is located towards the opposite end of the board from the USB connector, between the two NeoPixel LEDs. To interface with this sensor, you'll use I2C.

Connect to it in CircuitPython using board.SCL for clock and board.SDA for data.

Connect to it in Arduino using 5 for clock and 4 for data.

The APDS9960 sensor can do more than proximity sensing! It's capable of the following:

  • Proximity sensing up to about 6" away by bouncing IR light off an object
  • RGB color sensing can detect color when light reflects off of an object - good for bright colorful items like LEGO bricks
  • Ambient light sensing - how dark or bright is it in the room?
  • Basic gesture sensing using 4 cardinal locations of photodiodes - this sensor is a little tough to use but it does work with practice
  • Configurable interrupt pin that can fire when a certain proximity threshold is broken, or when a color sensor breaks a certain threshold.


Towards the end of the board opposite the USB connector are two RGB NeoPixel LEDs. These LEDs are controllable in CircuitPython using board.NeoPixel and Arduino using PIN_NEOPIXEL or 3. Set the number of pixels to 2 and you're ready to go!

Capacitive Touch Pads

On the end of the board, opposite the USB connector, are two capacitive touch pads, labeled 1 and 2.

To use with CircuitPython, address touch pad 1 as board.TOUCH1 and touch pad 2 as board.TOUCH2.

To use with Arduino, address touch pad 1 as 1 and touch pad 2 as 2.

ATSAMD21 Microcontroller

The center of the board is home to the SAMD21 microcontroller. This is the brain of the board.

Reset Button

Towards the center of the board, between the microcontroller and the proximity sensor/NeoPixel LED, is the reset button.

Tap once to reset the board. Tap twice to enter the bootloader (needed for installing CircuitPython).


On the back of the board are three pads that can be used for JTAG debugging. They are labeled, left to right:

  • SWD - The data pin.
  • SWC - The clock pin
  • Rst - The reset pin.

This guide was first published on Sep 29, 2021. It was last updated on Jul 19, 2024.

This page (Pinouts) was last updated on Mar 08, 2024.

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