Source code for adafruit_bno055

# The MIT License (MIT)
#
# Copyright (c) 2017 Radomir Dopieralski for Adafruit Industries.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.


"""
``adafruit_bno055``
===================

This is a CircuitPython driver for the Bosch BNO055 nine degree of freedom
inertial measurement unit module with sensor fusion.

* Author(s): Radomir Dopieralski
"""
import time

from micropython import const
from adafruit_bus_device.i2c_device import I2CDevice
from adafruit_register.i2c_struct import Struct, UnaryStruct

__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_BNO055.git"

_CHIP_ID = const(0xa0)

CONFIG_MODE = const(0x00)
ACCONLY_MODE = const(0x01)
MAGONLY_MODE = const(0x02)
GYRONLY_MODE = const(0x03)
ACCMAG_MODE = const(0x04)
ACCGYRO_MODE = const(0x05)
MAGGYRO_MODE = const(0x06)
AMG_MODE = const(0x07)
IMUPLUS_MODE = const(0x08)
COMPASS_MODE = const(0x09)
M4G_MODE = const(0x0a)
NDOF_FMC_OFF_MODE = const(0x0b)
NDOF_MODE = const(0x0c)

_POWER_NORMAL = const(0x00)
_POWER_LOW = const(0x01)
_POWER_SUSPEND = const(0x02)

_MODE_REGISTER = const(0x3d)
_PAGE_REGISTER = const(0x07)
_TRIGGER_REGISTER = const(0x3f)
_POWER_REGISTER = const(0x3e)
_ID_REGISTER = const(0x00)


class _ScaledReadOnlyStruct(Struct): # pylint: disable=too-few-public-methods
    def __init__(self, register_address, struct_format, scale):
        super(_ScaledReadOnlyStruct, self).__init__(
            register_address, struct_format)
        self.scale = scale

    def __get__(self, obj, objtype=None):
        result = super(_ScaledReadOnlyStruct, self).__get__(obj, objtype)
        return tuple(self.scale * v for v in result)

    def __set__(self, obj, value):
        raise NotImplementedError()


class _ReadOnlyUnaryStruct(UnaryStruct): # pylint: disable=too-few-public-methods
    def __set__(self, obj, value):
        raise NotImplementedError()


[docs]class BNO055: """ Driver for the BNO055 9DOF IMU sensor. """ temperature = _ReadOnlyUnaryStruct(0x34, 'B') """Measures the temperature of the chip in degrees Celsius.""" accelerometer = _ScaledReadOnlyStruct(0x08, '<hhh', 1/100) """Gives the raw accelerometer readings, in m/s. .. warning:: This is deprecated. Use `acceleration` instead. It'll work with other drivers too.""" acceleration = _ScaledReadOnlyStruct(0x08, '<hhh', 1/100) """Gives the raw accelerometer readings, in m/s.""" magnetometer = _ScaledReadOnlyStruct(0x0e, '<hhh', 1/16) """Gives the raw magnetometer readings in microteslas. .. warning:: This is deprecated. Use `magnetic` instead. It'll work with other drivers too.""" magnetic = _ScaledReadOnlyStruct(0x0e, '<hhh', 1/16) """Gives the raw magnetometer readings in microteslas.""" gyroscope = _ScaledReadOnlyStruct(0x14, '<hhh', 1/900) """Gives the raw gyroscope reading in degrees per second.""" euler = _ScaledReadOnlyStruct(0x1a, '<hhh', 1/16) """Gives the calculated orientation angles, in degrees.""" quaternion = _ScaledReadOnlyStruct(0x20, '<hhhh', 1/(1<<14)) """Gives the calculated orientation as a quaternion.""" linear_acceleration = _ScaledReadOnlyStruct(0x28, '<hhh', 1/100) """Returns the linear acceleration, without gravity, in m/s.""" gravity = _ScaledReadOnlyStruct(0x2e, '<hhh', 1/100) """Returns the gravity vector, without acceleration in m/s.""" def __init__(self, i2c, address=0x28): self.i2c_device = I2CDevice(i2c, address) self.buffer = bytearray(2) chip_id = self._read_register(_ID_REGISTER) if chip_id != _CHIP_ID: raise RuntimeError("bad chip id (%x != %x)" % (chip_id, _CHIP_ID)) self.reset() self._write_register(_POWER_REGISTER, _POWER_NORMAL) self._write_register(_PAGE_REGISTER, 0x00) self._write_register(_TRIGGER_REGISTER, 0x00) time.sleep(0.01) self.mode = NDOF_MODE time.sleep(0.01) def _write_register(self, register, value): self.buffer[0] = register self.buffer[1] = value with self.i2c_device as i2c: i2c.write(self.buffer) def _read_register(self, register): self.buffer[0] = register with self.i2c_device as i2c: i2c.write(self.buffer, end=1, stop=False) i2c.readinto(self.buffer, start=1) return self.buffer[1]
[docs] def reset(self): """Resets the sensor to default settings.""" self.mode = CONFIG_MODE try: self._write_register(_TRIGGER_REGISTER, 0x20) except OSError: # error due to the chip resetting pass while True: # wait for the chip to reset time.sleep(0.01) try: chip_id = self._read_register(_ID_REGISTER) except OSError: chip_id = 0 if chip_id == _CHIP_ID: break
@property def mode(self): """ Switch the mode of operation and return the previous mode. Mode of operation defines which sensors are enabled and whether the measurements are absolute or relative: +------------------+-------+---------+------+----------+ | Mode | Accel | Compass | Gyro | Absolute | +==================+=======+=========+======+==========+ | CONFIG_MODE | - | - | - | - | +------------------+-------+---------+------+----------+ | ACCONLY_MODE | X | - | - | - | +------------------+-------+---------+------+----------+ | MAGONLY_MODE | - | X | - | - | +------------------+-------+---------+------+----------+ | GYRONLY_MODE | - | - | X | - | +------------------+-------+---------+------+----------+ | ACCMAG_MODE | X | X | - | - | +------------------+-------+---------+------+----------+ | ACCGYRO_MODE | X | - | X | - | +------------------+-------+---------+------+----------+ | MAGGYRO_MODE | - | X | X | - | +------------------+-------+---------+------+----------+ | AMG_MODE | X | X | X | - | +------------------+-------+---------+------+----------+ | IMUPLUS_MODE | X | - | X | - | +------------------+-------+---------+------+----------+ | COMPASS_MODE | X | X | - | X | +------------------+-------+---------+------+----------+ | M4G_MODE | X | X | - | - | +------------------+-------+---------+------+----------+ | NDOF_FMC_OFF_MODE| X | X | X | X | +------------------+-------+---------+------+----------+ | NDOF_MODE | X | X | X | X | +------------------+-------+---------+------+----------+ The default mode is ``NDOF_MODE``. """ return self._read_register(_MODE_REGISTER) @mode.setter def mode(self, new_mode): self._write_register(_MODE_REGISTER, new_mode) @property def external_crystal(self): """Switches the use of external crystal on or off.""" last_mode = self.mode self.mode = CONFIG_MODE self._write_register(_PAGE_REGISTER, 0x00) value = self._read_register(_TRIGGER_REGISTER) self.mode = last_mode return value == 0x80 @external_crystal.setter def use_external_crystal(self, value): last_mode = self.mode self.mode = CONFIG_MODE self._write_register(_PAGE_REGISTER, 0x00) self._write_register(_TRIGGER_REGISTER, 0x80 if value else 0x00) self.mode = last_mode time.sleep(0.01)