mirror of
https://github.com/supleed2/ELEC60013-ES-CW1.git
synced 2024-09-19 20:06:17 +00:00
106 lines
3.9 KiB
Python
106 lines
3.9 KiB
Python
"""Library for interacting with LIS3DH triple-axis accelerometer."""
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from importlib.resources import read_text
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from re import S
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from tabnanny import check
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import smbus2
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from time import sleep
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# Register addresses
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_CTRL_REG1 = bytes([0x20])
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_CTRL_REG2 = bytes([0x21])
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_CTRL_REG3 = bytes([0x22])
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_CTRL_REG4 = bytes([0x23])
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_CTRL_REG5 = bytes([0x24])
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_CTRL_REG6 = bytes([0x25])
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_REF_REG = bytes([0x26])
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_STATUS_REG = bytes([0x27])
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_OUT_X_L = bytes([0x28])
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_OUT_X_H = bytes([0x29])
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_OUT_Y_L = bytes([0x2A])
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_OUT_Y_H = bytes([0x2B])
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_OUT_Z_L = bytes([0x2C])
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_OUT_Z_H = bytes([0x2D])
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_INT1_CFG = bytes([0x30])
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_INT1_SRC = bytes([0x31])
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_INT1_THS = bytes([0x32])
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_INT1_DURATION = bytes([0x33])
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_INT2_CFG = bytes([0x34])
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_INT2_SRC = bytes([0x35])
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_INT2_THS = bytes([0x36])
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_INT2_DURATION = bytes([0x37])
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_CLICK_CFG = bytes([0x38])
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# Config flags
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SAMPLERATE_1HZ = bytes([0x17])
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SAMPLERATE_10HZ = bytes([0x27])
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SAMPLERATE_25HZ = bytes([0x37])
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HP_DISABLE = bytes([0x00])
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CTRL_REG3_V = bytes([0x40])
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CTRL_REG4_V = bytes([0x00]) # sensitivity set to 2g
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CTRL_REG5_V = bytes([0x08])
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INT1_THS_V = bytes([0x16]) # free-fall threshold at 350 mg
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INT1_DURATION_V = bytes([0x03])
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INT1_CFG_V = bytes([0x95])
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EMPTY = bytes([0x00])
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class lis3dh:
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def __init__(self, i2cBus, resolution=2, samplerate=10, i2cAddress=0x18):
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sleep(0.005)
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self.i2c = i2cBus
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self.addr = i2cAddress
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self.samplerate = samplerate
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i2cBus.pec = True # enable smbus2 Packet Error Checking
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res_modes = {
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2: 0b00, 4: 0b01,
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8: 0b10, 16: 0b11
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}
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sample_modes = {
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0:0x0, 1:0x1, 10:0x2, 25:0x3, 50:0x4,
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100:0x5, 200:0x6, 400:0x7
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}
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# Check if user-entered values are correct
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if resolution in res_modes:
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self.resolution = resolution
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else:
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raise Exception("Invalid resolution.")
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if samplerate in sample_modes:
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self.samplerate = sample_modes[samplerate]
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else:
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raise Exception("Invalid sample rate.")
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# First try; configure beginning from 0x20
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config0 = smbus2.i2c_msg.write(self.addr, [0x20,(sample_modes[samplerate]<<4)|0xF]) # Initialise in low power mode
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config1 = smbus2.i2c_msg.write(self.addr, [0xC1,0x00,0x00,0x00|self.resolution,0x00,0x00,0x00])
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config2 = smbus2.i2c_msg.write(self.addr, [0xB2,0x00,0x00]) # Configure 0x32 with MSB = 1 to increment
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config3 = smbus2.i2c_msg.write(self.addr, [0x30,0x00]) # Configure 0x30
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config4 = smbus2.i2c_msg.write(self.addr, [0x24,0x00]) # Configure 0x24 again
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self.i2c.i2c_rdwr(config0, config1, config2, config3, config4)
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def readAll(self) -> list:
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'''Read acceleration data from all axes. Returns values as a list [X,Y,Z].'''
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check_status = smbus2.i2c_msg.write(self.addr, [0x27])
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x = smbus2.i2c_msg.read(self.addr, 1)
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y = smbus2.i2c_msg.read(self.addr, 1)
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z = smbus2.i2c_msg.read(self.addr, 1)
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prepare_x = smbus2.i2c_msg.write(self.addr, [0x29])
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prepare_y = smbus2.i2c_msg.write(self.addr, [0x2B])
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prepare_z = smbus2.i2c_msg.write(self.addr, [0x2D])
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status = smbus2.i2c_msg.read(self.addr, 1)
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self.i2c.i2c_rdwr(check_status, status)
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while status.buf[0][0] & 0b1111 != 0b1111: # Wait for data to be available
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sleep(0.001)
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self.i2c.i2c_rdwr(check_status, status)
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if status.buf[0][0] & 0b1111 == 0b1111: # If data is available, read
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self.i2c.i2c_rdwr(prepare_x, x)
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self.i2c.i2c_rdwr(prepare_y, y)
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self.i2c.i2c_rdwr(prepare_z, z)
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X = int.from_bytes(x.buf[0],"big")
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Y = int.from_bytes(y.buf[0],"big")
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Z = int.from_bytes(z.buf[0],"big")
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# TODO: Need to format this so that it returns values in g
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return [X,Y,Z]
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else:
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return None # Should never get here lol |