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| -rw-r--r-- | drivers/lsm9ds1/lsm9ds1.py | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/lsm9ds1/lsm9ds1.py b/drivers/lsm9ds1/lsm9ds1.py new file mode 100644 index 000000000..5d9942a7b --- /dev/null +++ b/drivers/lsm9ds1/lsm9ds1.py @@ -0,0 +1,189 @@ +""" +The MIT License (MIT) + +Copyright (c) 2013, 2014 Damien P. George + +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. + + +LSM9DS1 - 9DOF inertial sensor of STMicro driver for MicroPython. +The sensor contains an accelerometer / gyroscope / magnetometer +Uses the internal FIFO to store up to 16 gyro/accel data, use the iter_accel_gyro generator to access it. + +Example usage: + +import time +from lsm9ds1 import LSM9DS1 +from machine import Pin, I2C + +lsm = LSM9DS1(I2C(1, scl=Pin(15), sda=Pin(14))) + +while (True): + #for g,a in lsm.iter_accel_gyro(): print(g,a) # using fifo + print('Accelerometer: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*lsm.accel())) + print('Magnetometer: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*lsm.magnet())) + print('Gyroscope: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*lsm.gyro())) + print("") + time.sleep_ms(100) +""" +import array + + +_WHO_AM_I = const(0xF) +_CTRL_REG1_G = const(0x10) +_INT_GEN_SRC_G = const(0x14) +_OUT_TEMP = const(0x15) +_OUT_G = const(0x18) +_CTRL_REG4_G = const(0x1E) +_STATUS_REG = const(0x27) +_OUT_XL = const(0x28) +_FIFO_CTRL_REG = const(0x2E) +_FIFO_SRC = const(0x2F) +_OFFSET_REG_X_M = const(0x05) +_CTRL_REG1_M = const(0x20) +_OUT_M = const(0x28) +_SCALE_GYRO = const(((245, 0), (500, 1), (2000, 3))) +_SCALE_ACCEL = const(((2, 0), (4, 2), (8, 3), (16, 1))) + + +class LSM9DS1: + def __init__(self, i2c, address_gyro=0x6B, address_magnet=0x1E): + self.i2c = i2c + self.address_gyro = address_gyro + self.address_magnet = address_magnet + # check id's of accelerometer/gyro and magnetometer + if (self.magent_id() != b"=") or (self.gyro_id() != b"h"): + raise OSError( + "Invalid LSM9DS1 device, using address {}/{}".format(address_gyro, address_magnet) + ) + # allocate scratch buffer for efficient conversions and memread op's + self.scratch = array.array("B", [0, 0, 0, 0, 0, 0]) + self.scratch_int = array.array("h", [0, 0, 0]) + self.init_gyro_accel() + self.init_magnetometer() + + def init_gyro_accel(self, sample_rate=6, scale_gyro=0, scale_accel=0): + """Initalizes Gyro and Accelerator. + sample rate: 0-6 (off, 14.9Hz, 59.5Hz, 119Hz, 238Hz, 476Hz, 952Hz) + scale_gyro: 0-2 (245dps, 500dps, 2000dps ) + scale_accel: 0-3 (+/-2g, +/-4g, +/-8g, +-16g) + """ + assert sample_rate <= 6, "invalid sampling rate: %d" % sample_rate + assert scale_gyro <= 2, "invalid gyro scaling: %d" % scale_gyro + assert scale_accel <= 3, "invalid accelerometer scaling: %d" % scale_accel + + i2c = self.i2c + addr = self.address_gyro + mv = memoryview(self.scratch) + # angular control registers 1-3 / Orientation + mv[0] = ((sample_rate & 0x07) << 5) | ((_SCALE_GYRO[scale_gyro][1] & 0x3) << 3) + mv[1:4] = b"\x00\x00\x00" + i2c.writeto_mem(addr, _CTRL_REG1_G, mv[:5]) + # ctrl4 - enable x,y,z, outputs, no irq latching, no 4D + # ctrl5 - enable all axes, no decimation + # ctrl6 - set scaling and sample rate of accel + # ctrl7,8 - leave at default values + # ctrl9 - FIFO enabled + mv[0] = mv[1] = 0x38 + mv[2] = ((sample_rate & 7) << 5) | ((_SCALE_ACCEL[scale_accel][1] & 0x3) << 3) + mv[3] = 0x00 + mv[4] = 0x4 + mv[5] = 0x2 + i2c.writeto_mem(addr, _CTRL_REG4_G, mv[:6]) + + # fifo: use continous mode (overwrite old data if overflow) + i2c.writeto_mem(addr, _FIFO_CTRL_REG, b"\x00") + i2c.writeto_mem(addr, _FIFO_CTRL_REG, b"\xc0") + + self.scale_gyro = 32768 / _SCALE_GYRO[scale_gyro][0] + self.scale_accel = 32768 / _SCALE_ACCEL[scale_accel][0] + + def init_magnetometer(self, sample_rate=7, scale_magnet=0): + """ + sample rates = 0-7 (0.625, 1.25, 2.5, 5, 10, 20, 40, 80Hz) + scaling = 0-3 (+/-4, +/-8, +/-12, +/-16 Gauss) + """ + assert sample_rate < 8, "invalid sample rate: %d (0-7)" % sample_rate + assert scale_magnet < 4, "invalid scaling: %d (0-3)" % scale_magnet + i2c = self.i2c + addr = self.address_magnet + mv = memoryview(self.scratch) + mv[0] = 0x40 | (sample_rate << 2) # ctrl1: high performance mode + mv[1] = scale_magnet << 5 # ctrl2: scale, normal mode, no reset + mv[2] = 0x00 # ctrl3: continous conversion, no low power, I2C + mv[3] = 0x08 # ctrl4: high performance z-axis + mv[4] = 0x00 # ctr5: no fast read, no block update + i2c.writeto_mem(addr, _CTRL_REG1_M, mv[:5]) + self.scale_factor_magnet = 32768 / ((scale_magnet + 1) * 4) + + def calibrate_magnet(self, offset): + """ + offset is a magnet vecor that will be substracted by the magnetometer + for each measurement. It is written to the magnetometer's offset register + """ + offset = [int(i * self.scale_factor_magnet) for i in offset] + mv = memoryview(self.scratch) + mv[0] = offset[0] & 0xFF + mv[1] = offset[0] >> 8 + mv[2] = offset[1] & 0xFF + mv[3] = offset[1] >> 8 + mv[4] = offset[2] & 0xFF + mv[5] = offset[2] >> 8 + self.i2c.writeto_mem(self.address_magnet, _OFFSET_REG_X_M, mv[:6]) + + def gyro_id(self): + return self.i2c.readfrom_mem(self.address_gyro, _WHO_AM_I, 1) + + def magent_id(self): + return self.i2c.readfrom_mem(self.address_magnet, _WHO_AM_I, 1) + + def magnet(self): + """Returns magnetometer vector in gauss. + raw_values: if True, the non-scaled adc values are returned + """ + mv = memoryview(self.scratch_int) + f = self.scale_factor_magnet + self.i2c.readfrom_mem_into(self.address_magnet, _OUT_M | 0x80, mv) + return (mv[0] / f, mv[1] / f, mv[2] / f) + + def gyro(self): + """Returns gyroscope vector in degrees/sec.""" + mv = memoryview(self.scratch_int) + f = self.scale_gyro + self.i2c.readfrom_mem_into(self.address_gyro, _OUT_G | 0x80, mv) + return (mv[0] / f, mv[1] / f, mv[2] / f) + + def accel(self): + """Returns acceleration vector in gravity units (9.81m/s^2).""" + mv = memoryview(self.scratch_int) + f = self.scale_accel + self.i2c.readfrom_mem_into(self.address_gyro, _OUT_XL | 0x80, mv) + return (mv[0] / f, mv[1] / f, mv[2] / f) + + def iter_accel_gyro(self): + """A generator that returns tuples of (gyro,accelerometer) data from the fifo.""" + while True: + fifo_state = int.from_bytes( + self.i2c.readfrom_mem(self.address_gyro, _FIFO_SRC, 1), "big" + ) + if fifo_state & 0x3F: + # print("Available samples=%d" % (fifo_state & 0x1f)) + yield self.gyro(), self.accel() + else: + break |