Python & CircuitPython

It's easy to use the BNO055 sensor with Python and CircuitPython, and the Adafruit CircuitPython BNO055 library.  This library allows you to easily write Python code that reads the acceleration and orientation of the sensor.

You can use this sensor with any CircuitPython microcontroller board or with a computer that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.

CircuitPython Microcontroller Wiring

First wire up a BNO055 to your board exactly as shown on the previous pages for Arduino using the I2C interface.  Here's an example of wiring a Feather M0 to the sensor with I2C:

  • Board 3V to sensor VIN
  • Board GND to sensor GND
  • Board SCL to sensor SCL
  • Board SDA to sensor SDA

Python Computer Wiring

Since there's dozens of Linux computers/boards you can use we will show wiring for Raspberry Pi. For other platforms, please visit the guide for CircuitPython on Linux to see whether your platform is supported

Here's the Raspberry Pi wired with I2C:

  • Pi 3V3 to sensor VIN
  • Pi GND to sensor GND
  • Pi SCL to sensor SCL
  • Pi SDA to sensor SDA
Raspberry Pi computers do not have I2C clock stretching support so they don't work well with the BNO055 - there's hacky workarounds, but it's not recommended!

CircuitPython Installation of BNO055 Library

Next you'll need to install the Adafruit CircuitPython BNO055 library on your CircuitPython board.

First make sure you are running the latest version of Adafruit CircuitPython for your board.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle.  For example the Circuit Playground Express guide has a great page on how to install the library bundle for both express and non-express boards.

Remember for non-express boards like the Trinket M0, Gemma M0, and Feather/Metro M0 basic you'll need to manually install the necessary libraries from the bundle:

  • adafruit_bno055.mpy
  • adafruit_bus_device
  • adafruit_register

Before continuing make sure your board's lib folder or root filesystem has the adafruit_bno055.mpy, adafruit_bus_device, and adafruit_register files and folders copied over.

Next connect to the board's serial REPL so you are at the CircuitPython >>> prompt.

Python Installation of BNO055 Library

You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling I2C on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready!

Once that's done, from your command line run the following command:

  • sudo pip3 install adafruit-circuitpython-bno055

If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!

Raspberry Pi computers do not have I2C clock stretching support so they don't work well with the BNO055 - you can try slowing down I2C

To use this sensor, you must enable i2c slowdown on the Raspberry Pi device tree overlay. Check out this guide for instructions!

CircuitPython & Python Usage

To demonstrate the usage of the sensor we'll initialize it and read the acceleration, orientation (in Euler angles), and more from the board's Python REPL.  First initialize the I2C bus and create an instance of the sensor by running:

Download: file
import board
import busio
import adafruit_bno055
i2c = busio.I2C(board.SCL, board.SDA)
sensor = adafruit_bno055.BNO055(i2c)

Now you're ready to read values from the sensor using any of these properties:

  • temperature - The sensor temperature in degrees Celsius.
  • acceleration - This is a 3-tuple of X, Y, Z axis accelerometer values in meters per second squared.
  • magnetic - This is a 3-tuple of X, Y, Z axis magnetometer values in microteslas.
  • gyro - This is a 3-tuple of X, Y, Z axis gyroscope values in degrees per second.
  • euler - This is a 3-tuple of orientation Euler angle values.
  • quaternion - This is a 4-tuple of orientation quaternion values.
  • linear_acceleration - This is a 3-tuple of X, Y, Z linear acceleration values (i.e. without effect of gravity) in meters per second squared.
  • gravity - This is a 3-tuple of X, Y, Z gravity acceleration values (i.e. without the effect of linear acceleration) in meters per second squared.
Download: file

That's all there is to using the BNO055 sensor with CircuitPython!

Here's a complete example that prints each of the properties every second. Save this as on your board and look for the output in the serial REPL.

Full Example Code

import time
import board
import busio
import adafruit_bno055

i2c = busio.I2C(board.SCL, board.SDA)
sensor = adafruit_bno055.BNO055(i2c)

while True:
    print('Temperature: {} degrees C'.format(sensor.temperature))
    print('Accelerometer (m/s^2): {}'.format(sensor.acceleration))
    print('Magnetometer (microteslas): {}'.format(sensor.magnetic))
    print('Gyroscope (rad/sec): {}'.format(sensor.gyro))
    print('Euler angle: {}'.format(sensor.euler))
    print('Quaternion: {}'.format(sensor.quaternion))
    print('Linear acceleration (m/s^2): {}'.format(sensor.linear_acceleration))
    print('Gravity (m/s^2): {}'.format(sensor.gravity))

This guide was first published on Apr 22, 2015. It was last updated on Apr 22, 2015. This page (Python & CircuitPython) was last updated on Nov 11, 2019.