BNO055 USB Stick Python driver

TL;DR: "Swiss army knife" for using BNO055 USB Stick under Linux from python3.

BNO055 USB Stick comes with Development Desktop 2.0 software package, which is available for Windows only.

If you have a BNO055 USB Stick and want to use it on a Linux platform (e.g. Ubuntu, Raspbian, Yocto, Suse, etc.) this repo provides you with a python 3 driver, capable of reading / writing registers / burst read, and stream data read.

OS Prerequisites

1. When plugged in on a Linux system, the BNO055 USB Stick should appear as /dev/ttyACM* device. This device is a so-called cdc_acm (communication device class), but let us leave these details for now.

2. Your Linux user must be a member of the dialout group (e.g. see this thread) to be able to read/write ttyACM* devices without root privileges.

3. udev is installed on the system. We do autodetect the USB stick by relying on information from udev.

Installation

pip install bno055_usb_stick_py

Supported Python version

python v3.6+

Python dependencies

TL;DR: install (i) pyserial, (ii) pyudev, (iii) dataclasses (if using python3.6), and (iv) optionally: pyquaternion and matplotlib, or use environment.yml to create conda environment with dependencies resolved.

For further details regarding creating conda senvironment read this guide.

Quick start

Read BNO register:

from bno055_usb_stick_py import BnoUsbStick
bno_usb_stick = BnoUsbStick()
reg_addr = 0x00
reg_val = bno_usb_stick.read_register(reg_addr)
print(f"bno chip id addr: 0x{reg_addr:02X}, value: 0x{reg_val:02X}")

Write register:

from bno055_usb_stick_py import BnoUsbStick
bno_usb_stick = BnoUsbStick()
reg_addr = 0x3F
reg_value = 0x01
bno_usb_stick.write_register(reg_addr, reg_value)
print(f"bno self test started!")

Burst register read:

from bno055_usb_stick_py import BnoUsbStick
bno_usb_stick = BnoUsbStick()
reg_start_addr = 0x08
num_registers = 0x12
burst_read_result = bno_usb_stick.burst_read(reg_start_addr, num_registers)
print(f"bno burst read result: {burst_read_result}")

Get 10 packets in streaming mode (using generator):

from bno055_usb_stick_py import BnoUsbStick

bno_usb_stick = BnoUsbStick()
bno_usb_stick.activate_streaming()
for packet in bno_usb_stick.recv_streaming_generator(num_packets=10):
    print(f"bno data: {packet}")

Get 100 packets in streaming mode (by receiving single packets):

from bno055_usb_stick_py import BnoUsbStick
bno_usb_stick = BnoUsbStick()
bno_usb_stick.activate_streaming()
for _ in range(100):
    packet = bno_usb_stick.recv_streaming_packet()
    print(f"{packet}")

Receive infinite number of packets (in case you wait infinite time :wink: ):

from bno055_usb_stick_py import BnoUsbStick
bno_usb_stick = BnoUsbStick()
bno_usb_stick.activate_streaming()
for packet in bno_usb_stick.recv_streaming_generator():
    print(f"{packet}")

Bno USB Stick Data Packet

When receiving data in streaming mode, the result is an object of BNO055 data class (from bno055.py) file.

BNO055 data class has the following fields:

from bno055_usb_stick_py import BNO055
bno_data = BNO055()
bno_data.a_raw  # raw accelerometer data (a_raw_x, a_raw_y, a_raw_z)
bno_data.g_raw  # raw gyro data (g_raw_x, g_raw_y, g_raw_z)
bno_data.m_raw  # raw magnetometer data (m_raw_x, m_raw_y, m_raw_z)
bno_data.euler_raw  # raw euler angles (heading, roll, pitch)
bno_data.quaternion_raw  # raw quaternion data (q_raw_w, q_raw_x, q_raw_y, q_raw_z)
bno_data.lin_a_raw  # raw linear acceleration data (lin_a_raw_x, lin_a_raw_y, lin_a_raw_z)
bno_data.gravity_raw  # raw gravity vector (gravity_raw_x, gravity_raw_y, gravity_raw_z)
bno_data.a  # accelerometer (a_x, a_y, a_z)
bno_data.g  # gyroscope (g_x, g_y, g_z)
bno_data.m  # magnetometer (m_x, m_y, m_z)
bno_data.euler  # euler angler (heading, roll, pitch)
bno_data.quaternion  # quaternion values (q_w, q_x, q_y, q_z)
bno_data.lin_a  # linear acceleration (lin_a_x, lin_a_y, lin_a_z)
bno_data.gravity  # gravity vector (gravity_x, gravity_y, gravity_z)
bno_data.temp  # temperature register
bno_data.calib_stat  # calibration status (addr 0x35) register
bno_data.st_result  # status result (addr 0x36) register
bno_data.int_sta  # interrupt status (addr 0x37) register
bno_data.sys_clk_status  # system clock status (addr 0x38) register
bno_data.sys_status  # system status (addr 0x39) register

Prevent modem manager to capture serial device

When plugging bno_usb_stick on Ubuntu, the device is unavailable for the first 10-15 seconds, due to the fact that ModemManager process takes over and tries to use the device.

To avoid this Ubuntu-specific behavior, add an exception to the udev rules, s.t. the ModemManager ignores the bno_usb_stick. Run the script:

python disable_modem_manager_bno_usb_stick.py

The script requires root privileges. Essentially it copies the 97-ttyacm.rules file to /etc/udev/rules.d and reloads the udev rules.

Maintainer

Dr. Konstantin Selyunin, for suggestions / questions / comments please contact: selyunin [dot] k [dot] v [at] gmail [dot] com