Merge pull request #1 from LEG-Industries/kacper

Pull LIS3DH Lib into testing branch

lis3dh.py

@@ -0,0 +1,136 @@
+"""Library for interacting with LIS3DH triple-axis accelerometer."""
+
+from importlib.resources import read_text
+from re import S
+from tabnanny import check
+import smbus2
+from time import sleep
+
+# Register addresses
+_CTRL_REG1 = bytes([0x20])
+_CTRL_REG2 = bytes([0x21])
+_CTRL_REG3 = bytes([0x22])
+_CTRL_REG4 = bytes([0x23])
+_CTRL_REG5 = bytes([0x24])
+_CTRL_REG6 = bytes([0x25])
+_REF_REG = bytes([0x26])
+_STATUS_REG = bytes([0x27])
+_OUT_X_L = bytes([0x28])
+_OUT_X_H = bytes([0x29])
+_OUT_Y_L = bytes([0x2A])
+_OUT_Y_H = bytes([0x2B])
+_OUT_Z_L = bytes([0x2C])
+_OUT_Z_H = bytes([0x2D])
+_INT1_CFG = bytes([0x30])
+_INT1_SRC = bytes([0x31])
+_INT1_THS = bytes([0x32])
+_INT1_DURATION = bytes([0x33])
+_INT2_CFG = bytes([0x34])
+_INT2_SRC = bytes([0x35])
+_INT2_THS = bytes([0x36])
+_INT2_DURATION = bytes([0x37])
+_CLICK_CFG = bytes([0x38])
+# Config flags
+SAMPLERATE_1HZ  = bytes([0x17])
+SAMPLERATE_10HZ = bytes([0x27])
+SAMPLERATE_25HZ = bytes([0x37])
+HP_DISABLE = bytes([0x00])
+CTRL_REG3_V = bytes([0x40])
+CTRL_REG4_V = bytes([0x00]) # sensitivity set to 2g
+CTRL_REG5_V = bytes([0x08])
+INT1_THS_V = bytes([0x16]) # free-fall threshold at 350 mg
+INT1_DURATION_V = bytes([0x03])
+INT1_CFG_V = bytes([0x95])
+EMPTY = bytes([0x00])
+
+class lis3dh:
+    def __init__(self, i2cBus, samplerate=10, i2cAddress=0x18):
+        sleep(0.005)
+        self.i2c = i2cBus
+        self.addr = i2cAddress
+        self.samplerate = samplerate
+        i2cBus.pec = True  # enable smbus2 Packet Error Checking
+        sample_modes = {
+            0:0x0, 1:0x1, 10:0x2, 25:0x3, 50:0x4,
+            100:0x5, 200:0x6, 400:0x7
+        }
+
+        # Check if user-entered values are correct
+        if samplerate in sample_modes:
+            self.samplerate = sample_modes[samplerate]
+        else:
+            raise Exception("Invalid sample rate.")
+
+        # Configure all registers in +-2g mode
+        c0 = smbus2.i2c_msg.write(self.addr, [0x20,(sample_modes[samplerate]<<4)|0xF]) # Initialise in low power mode
+        c1 = smbus2.i2c_msg.write(self.addr, [0x21,0x0A])
+        c2 = smbus2.i2c_msg.write(self.addr, [0x22,0x40])
+        c3 = smbus2.i2c_msg.write(self.addr, [0x23,0x00])
+        c4 = smbus2.i2c_msg.write(self.addr, [0x24,0x0A])
+        c5 = smbus2.i2c_msg.write(self.addr, [0x25,0x20])
+        c6 = smbus2.i2c_msg.write(self.addr, [0x2E,0x00])
+        c7 = smbus2.i2c_msg.write(self.addr, [0x30,0x95])
+        c8 = smbus2.i2c_msg.write(self.addr, [0x32,0x16])
+        c9 = smbus2.i2c_msg.write(self.addr, [0x33,0x03])
+        c10 = smbus2.i2c_msg.write(self.addr, [0x34,0x3F])
+        c11 = smbus2.i2c_msg.write(self.addr, [0x36,0x4A])
+        c12 = smbus2.i2c_msg.write(self.addr, [0x24,0x0A]) # Configure 0x24 again
+        self.i2c.i2c_rdwr(c0,c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12)
+
+    def resetint1(self) -> bool:
+        '''Read INT1_SRC to reset it after an interrupt event.'''
+        int1_src_loc = smbus2.i2c_msg.write(self.addr, [0x31])
+        read_int1_src = smbus2.i2c_msg.read(self.addr, 1)
+        self.i2c.i2c_rdwr(int1_src_loc,read_int1_src)
+        if read_int1_src.bug[0] != None:
+            return True
+        else:
+            return False
+        
+    def resetint2(self) -> bool:
+        '''Read INT2_SRC to reset it after an interrupt event.'''
+        int2_src_loc = smbus2.i2c_msg.write(self.addr, [0x35])
+        read_int2_src = smbus2.i2c_msg.read(self.addr, 1)
+        self.i2c.i2c_rdwr(int2_src_loc,read_int2_src)
+        if read_int2_src.bug[0] != None:
+            return True
+        else:
+            return False
+
+    def readAll(self) -> list:
+        '''Read acceleration data from all axes. Returns values as a list [X,Y,Z].'''
+        check_status = smbus2.i2c_msg.write(self.addr, [0x27])
+        x = smbus2.i2c_msg.read(self.addr, 1)
+        y = smbus2.i2c_msg.read(self.addr, 1)
+        z = smbus2.i2c_msg.read(self.addr, 1)
+        prepare_x = smbus2.i2c_msg.write(self.addr, [0x29])
+        prepare_y = smbus2.i2c_msg.write(self.addr, [0x2B])
+        prepare_z = smbus2.i2c_msg.write(self.addr, [0x2D])
+        status = smbus2.i2c_msg.read(self.addr, 1)
+        self.i2c.i2c_rdwr(check_status, status)
+
+        while status.buf[0][0] & 0b1111 != 0b1111: # Wait for data to be available
+            sleep(0.001)
+            self.i2c.i2c_rdwr(check_status, status)
+
+        if status.buf[0][0] & 0b1111 == 0b1111: # If data is available, read
+            self.i2c.i2c_rdwr(prepare_x, x)
+            self.i2c.i2c_rdwr(prepare_y, y)
+            self.i2c.i2c_rdwr(prepare_z, z)
+            X = int.from_bytes(x.buf[0],"big")
+            Y = int.from_bytes(y.buf[0],"big")
+            Z = int.from_bytes(z.buf[0],"big")
+
+            # Convert from binary 2s complement to useful data
+            new_values = []
+            for D in [X,Y,Z]:
+                MSB = D >> 7
+                if MSB == 1:
+                    res = (-128 + (D - 128))*self.resolution/128
+                else:
+                    res = (D*self.resolution)/128
+                new_values.append(res)
+
+            return new_values
+        else:
+            return None # Should never get here lol