Note that there are two versions of this board in the wild. It was updated on Feb. 12, 2020 to have a USB C connector, additional pinouts, and other features (see product page for more info).

Pinouts for both the new version (USB C) and the original version are below.

I2C and SPI share the same pins, so only one mode can be used at a time.

Power Pins

  • 5V - this is the 5V power from the USB input.
  • GND - this is the common ground for all power and logic.
  • 3V power output - The new version has a 3.3V power output pin for up to 500mA

GPIO Pins

  • D4 to D7 - can be used as either digital inputs or outputs.
  • C0 to C7 - can be used as either digital inputs or outputs.

I2C Pins

  • SCL - the I2C clock signal is on D0.
  • SDA - the I2C data is on D1+D2.
  • I2C switch - The new version has a switch that connects D1 and D2 for easy I2C interfacing. Move the switch to ON to use I2C and/or the STEMMA QT connector. You can then use either D1 or D2 for SDA.

On the original version only: Note that there are two pins (D1 and D2) which must be tied together and treated as one to use I2C.

SPI Pins

  • SCLK - the SPI clock signal is on D0.
  • MOSI - Master Out, Slave In is on D1.
  • MISO - Master In, Slave Out is on D2.
  • CS0 - Chip Select is on D3. This is not used by Blinka, instead use one of the GPIO pins from above (see example section).

STEMMA QT

  • STEMMA QT connector - The new version has a Stemma QT connector that lets you plug & play any Stemma QT or Qwiic devices, sensors and displays. To use: make sure the I2C switch is set to ON to use the STEMMA QT connector.
This guide was first published on Sep 29, 2019. It was last updated on Sep 29, 2019.
This page (Pinout) was last updated on Jun 03, 2020.