drivers/lsm9ds1: Add LSM9DS1 IMU driver.
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iabdalkader
Damien George
parent
fc6d989f8c
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6c07e9eb27
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"""
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The MIT License (MIT)
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Copyright (c) 2013, 2014 Damien P. George
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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LSM9DS1 - 9DOF inertial sensor of STMicro driver for MicroPython.
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The sensor contains an accelerometer / gyroscope / magnetometer
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Uses the internal FIFO to store up to 16 gyro/accel data, use the iter_accel_gyro generator to access it.
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Example usage:
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import time
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from lsm9ds1 import LSM9DS1
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from machine import Pin, I2C
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lsm = LSM9DS1(I2C(1, scl=Pin(15), sda=Pin(14)))
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while (True):
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#for g,a in lsm.iter_accel_gyro(): print(g,a) # using fifo
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print('Accelerometer: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*lsm.accel()))
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print('Magnetometer: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*lsm.magnet()))
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print('Gyroscope: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*lsm.gyro()))
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print("")
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time.sleep_ms(100)
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"""
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import array
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_WHO_AM_I = const(0xF)
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_CTRL_REG1_G = const(0x10)
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_INT_GEN_SRC_G = const(0x14)
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_OUT_TEMP = const(0x15)
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_OUT_G = const(0x18)
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_CTRL_REG4_G = const(0x1E)
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_STATUS_REG = const(0x27)
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_OUT_XL = const(0x28)
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_FIFO_CTRL_REG = const(0x2E)
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_FIFO_SRC = const(0x2F)
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_OFFSET_REG_X_M = const(0x05)
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_CTRL_REG1_M = const(0x20)
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_OUT_M = const(0x28)
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_SCALE_GYRO = const(((245, 0), (500, 1), (2000, 3)))
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_SCALE_ACCEL = const(((2, 0), (4, 2), (8, 3), (16, 1)))
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class LSM9DS1:
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def __init__(self, i2c, address_gyro=0x6B, address_magnet=0x1E):
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self.i2c = i2c
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self.address_gyro = address_gyro
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self.address_magnet = address_magnet
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# check id's of accelerometer/gyro and magnetometer
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if (self.magent_id() != b"=") or (self.gyro_id() != b"h"):
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raise OSError(
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"Invalid LSM9DS1 device, using address {}/{}".format(address_gyro, address_magnet)
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)
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# allocate scratch buffer for efficient conversions and memread op's
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self.scratch = array.array("B", [0, 0, 0, 0, 0, 0])
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self.scratch_int = array.array("h", [0, 0, 0])
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self.init_gyro_accel()
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self.init_magnetometer()
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def init_gyro_accel(self, sample_rate=6, scale_gyro=0, scale_accel=0):
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"""Initalizes Gyro and Accelerator.
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sample rate: 0-6 (off, 14.9Hz, 59.5Hz, 119Hz, 238Hz, 476Hz, 952Hz)
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scale_gyro: 0-2 (245dps, 500dps, 2000dps )
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scale_accel: 0-3 (+/-2g, +/-4g, +/-8g, +-16g)
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"""
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assert sample_rate <= 6, "invalid sampling rate: %d" % sample_rate
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assert scale_gyro <= 2, "invalid gyro scaling: %d" % scale_gyro
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assert scale_accel <= 3, "invalid accelerometer scaling: %d" % scale_accel
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i2c = self.i2c
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addr = self.address_gyro
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mv = memoryview(self.scratch)
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# angular control registers 1-3 / Orientation
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mv[0] = ((sample_rate & 0x07) << 5) | ((_SCALE_GYRO[scale_gyro][1] & 0x3) << 3)
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mv[1:4] = b"\x00\x00\x00"
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i2c.writeto_mem(addr, _CTRL_REG1_G, mv[:5])
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# ctrl4 - enable x,y,z, outputs, no irq latching, no 4D
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# ctrl5 - enable all axes, no decimation
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# ctrl6 - set scaling and sample rate of accel
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# ctrl7,8 - leave at default values
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# ctrl9 - FIFO enabled
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mv[0] = mv[1] = 0x38
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mv[2] = ((sample_rate & 7) << 5) | ((_SCALE_ACCEL[scale_accel][1] & 0x3) << 3)
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mv[3] = 0x00
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mv[4] = 0x4
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mv[5] = 0x2
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i2c.writeto_mem(addr, _CTRL_REG4_G, mv[:6])
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# fifo: use continous mode (overwrite old data if overflow)
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i2c.writeto_mem(addr, _FIFO_CTRL_REG, b"\x00")
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i2c.writeto_mem(addr, _FIFO_CTRL_REG, b"\xc0")
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self.scale_gyro = 32768 / _SCALE_GYRO[scale_gyro][0]
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self.scale_accel = 32768 / _SCALE_ACCEL[scale_accel][0]
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def init_magnetometer(self, sample_rate=7, scale_magnet=0):
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"""
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sample rates = 0-7 (0.625, 1.25, 2.5, 5, 10, 20, 40, 80Hz)
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scaling = 0-3 (+/-4, +/-8, +/-12, +/-16 Gauss)
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"""
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assert sample_rate < 8, "invalid sample rate: %d (0-7)" % sample_rate
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assert scale_magnet < 4, "invalid scaling: %d (0-3)" % scale_magnet
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i2c = self.i2c
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addr = self.address_magnet
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mv = memoryview(self.scratch)
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mv[0] = 0x40 | (sample_rate << 2) # ctrl1: high performance mode
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mv[1] = scale_magnet << 5 # ctrl2: scale, normal mode, no reset
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mv[2] = 0x00 # ctrl3: continous conversion, no low power, I2C
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mv[3] = 0x08 # ctrl4: high performance z-axis
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mv[4] = 0x00 # ctr5: no fast read, no block update
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i2c.writeto_mem(addr, _CTRL_REG1_M, mv[:5])
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self.scale_factor_magnet = 32768 / ((scale_magnet + 1) * 4)
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def calibrate_magnet(self, offset):
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"""
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offset is a magnet vecor that will be substracted by the magnetometer
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for each measurement. It is written to the magnetometer's offset register
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"""
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offset = [int(i * self.scale_factor_magnet) for i in offset]
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mv = memoryview(self.scratch)
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mv[0] = offset[0] & 0xFF
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mv[1] = offset[0] >> 8
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mv[2] = offset[1] & 0xFF
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mv[3] = offset[1] >> 8
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mv[4] = offset[2] & 0xFF
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mv[5] = offset[2] >> 8
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self.i2c.writeto_mem(self.address_magnet, _OFFSET_REG_X_M, mv[:6])
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def gyro_id(self):
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return self.i2c.readfrom_mem(self.address_gyro, _WHO_AM_I, 1)
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def magent_id(self):
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return self.i2c.readfrom_mem(self.address_magnet, _WHO_AM_I, 1)
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def magnet(self):
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"""Returns magnetometer vector in gauss.
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raw_values: if True, the non-scaled adc values are returned
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"""
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mv = memoryview(self.scratch_int)
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f = self.scale_factor_magnet
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self.i2c.readfrom_mem_into(self.address_magnet, _OUT_M | 0x80, mv)
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return (mv[0] / f, mv[1] / f, mv[2] / f)
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def gyro(self):
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"""Returns gyroscope vector in degrees/sec."""
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mv = memoryview(self.scratch_int)
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f = self.scale_gyro
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self.i2c.readfrom_mem_into(self.address_gyro, _OUT_G | 0x80, mv)
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return (mv[0] / f, mv[1] / f, mv[2] / f)
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def accel(self):
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"""Returns acceleration vector in gravity units (9.81m/s^2)."""
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mv = memoryview(self.scratch_int)
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f = self.scale_accel
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self.i2c.readfrom_mem_into(self.address_gyro, _OUT_XL | 0x80, mv)
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return (mv[0] / f, mv[1] / f, mv[2] / f)
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def iter_accel_gyro(self):
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"""A generator that returns tuples of (gyro,accelerometer) data from the fifo."""
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while True:
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fifo_state = int.from_bytes(
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self.i2c.readfrom_mem(self.address_gyro, _FIFO_SRC, 1), "big"
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)
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if fifo_state & 0x3F:
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# print("Available samples=%d" % (fifo_state & 0x1f))
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yield self.gyro(), self.accel()
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else:
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break
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