Note: The pin order on the STEMMA QT version of the board is not the same as the original version. The pins are the same otherwise.

Power Pins

• VIN: 3.3-5.0V power supply input
• 3VO: 3.3V output from the on-board linear voltage regulator, you can grab up to about 50mA as necessary
• GND: The common/GND pin for power and logic

I2C Pins

• SCL - I2C clock pin, connect to your microcontrollers I2C clock line. This pin can be used with 3V or 5V logic, and there's a 10K pullup on this pin.
• SDA - I2C data pin, connect to your microcontrollers I2C data line. This pin can be used with 3V or 5V logic, and there's a 10K pullup on this pin.

STEMMA QT version

• STEMMA QT - These connectors allow you to connectors to dev boards with STEMMA QT connectors or to other things with various associated accessories

Other Pins

• RST: Hardware reset pin.  Set this pin low then high to cause a reset on the sensor. This pin is 5V safe.
• INT: The HW interrupt output pin, which can be configured to generate an interrupt signal when certain events occur like movement detected by the accelerometer, etc. (not currently supported in the Adafruit library, but the chip and HW is capable of generating this signal). The voltage level out is 3V
• ADR: Set this pin high to change the default I2C address for the BNO055 if you need to connect two ICs on the same I2C bus. 

• PS0 and PS1: These pins can be used to change the mode of the device (it can also do HID-I2C and UART) and also are provided in case Bosch provides a firmware update at some point for the ARM Cortex M0 MCU inside the sensor. They should normally be left unconnected.