The default I2C address is 0x36.

Power Pins

• VIN - This is the power pin. Since the chip uses 3 VDC, we have included a voltage regulator on board that will take 3-5VDC and safely convert it down. To power the board, give it the same power as the logic level of your microcontroller - e.g. for a 5V microcontroller like Arduino, use 5V.
• 3Vo - This is the 3.3V output from the voltage regulator. You can grab up to 100mA from this if you like.
• GND - This is the common ground for power and logic.

I2C Logic Pins

The default I2C address is 0x36.

• SCL - This is the I2C clock pin. Connect to your microcontroller I2C clock line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.
• SDA - This is the I2C data pin. Connect to your microcontroller I2C data line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.
• STEMMA QT - These connectors allow you to connect to development boards with STEMMA QT connectors or to other things with various associated accessories.

Other Pins

• INT - This is the interrupt pin. There is a red INT LED on the back of the board that, if this pin is configured, blinks when the interrupt fires.

Address Jumpers

On the back of the board are three address jumpers, labeled A0, A1, and A2. These jumpers allow you to chain up to 8 of these boards on the same pair of I2C clock and data pins. To do so, you solder the jumpers "closed" by connecting the two pads.

If you happen to need more than 8, it's possible to set the I2C address with a special address-change command that is saved to the onboard non-volatile EEPROM memory.

The default I2C address is 0x36. The other address options can be calculated by "adding" the A0/A1/A2 to the base of 0x36.

A0 sets the lowest bit with a value of 1, A1 sets the next bit with a value of 2 and A2 sets the next bit with a value of 4. The final address is 0x36 + A2 + A1 + A0 which would be 0x3D.


If only A0 is closed, the address is 0x36 + 1 = 0x37


If only A1 is closed, the address is 0x36 + 2 = 0x38


If only A2 is closed, the address is 0x36 + 4 = 0x3A

The table below shows all possible addresses, and whether the pin(s) should be low (closed) or high (open).

seesaw Pins

• Onboard NeoPixel LED - This RGB LED is controlled over I2C using the seesaw library for additional visual feedback or keep it off if you like. It is connected to seesaw pin 6.
• Rotary encoder - The rotary encoder is mounted in the center of the board. You will have to solder it if you order PID4991. It comes pre-soldered on PID5880. The push button on the rotary encoder is connected to seesaw pin 24.