Updated LTR329ALS01.py for value corrections

Author: Alex Bucknall

pysense/lib/LTR329ALS01.py

@@ -1,20 +1,24 @@
 import time
+from machine import I2C
 
 class LTR329ALS01:
+    ALS_I2CADDR = const(0x29) # The device's I2C address
 
-    ALS_I2CADDR = const(0x29)
     ALS_CONTR_REG = const(0x80)
-    ALS_MEAS_REG = const(0x85)
-    ALS_DATA_CH0_LOW = const(0x8A)
-    ALS_DATA_CH0_HIGH = const(0x8B)
+    ALS_MEAS_RATE_REG = const(0x85)
+
     ALS_DATA_CH1_LOW = const(0x88)
     ALS_DATA_CH1_HIGH = const(0x89)
-    ALS_GAIN_1X = const(0x01)
-    ALS_GAIN_2X = const(0x05)
-    ALS_GAIN_4X = const(0x09)
-    ALS_GAIN_8X = const(0x0D)
-    ALS_GAIN_48X = const(0x19)
-    ALS_GAIN_96X = const(0x1D)
+    ALS_DATA_CH0_LOW = const(0x8A)
+    ALS_DATA_CH0_HIGH = const(0x8B)
+
+    ALS_GAIN_1X = const(0x00)
+    ALS_GAIN_2X = const(0x01)
+    ALS_GAIN_4X = const(0x02)
+    ALS_GAIN_8X = const(0x03)
+    ALS_GAIN_48X = const(0x06)
+    ALS_GAIN_96X = const(0x07)
+
     ALS_INT_50 = const(0x01)
     ALS_INT_100 = const(0x00)
     ALS_INT_150 = const(0x04)
@@ -23,37 +27,44 @@ class LTR329ALS01:
     ALS_INT_300 = const(0x06)
     ALS_INT_350 = const(0x07)
     ALS_INT_400 = const(0x03)
+
     ALS_RATE_50 = const(0x00)
     ALS_RATE_100 = const(0x01)
     ALS_RATE_200 = const(0x02)
     ALS_RATE_500 = const(0x03)
     ALS_RATE_1000 = const(0x04)
     ALS_RATE_2000 = const(0x05)
 
-    def __init__(self, pysense=None, sda='P22', scl='P21', gain=ALS_GAIN_1X, integration=ALS_INT_100, rate=ALS_RATE_500):
+    def __init__(self, pysense = None, sda = 'P22', scl = 'P21', gain = ALS_GAIN_1X, integration = ALS_INT_100, rate = ALS_RATE_500):
         if pysense is not None:
             self.i2c = pysense.i2c
         else:
-            from machine import I2C
             self.i2c = I2C(0, mode=I2C.MASTER, pins=(sda, scl))
 
-        self.i2c.writeto_mem(ALS_I2CADDR, ALS_CONTR_REG, bytearray([gain]))
-        meas = self._concat_hex(integration, rate)
-        self.i2c.writeto_mem(ALS_I2CADDR, ALS_MEAS_REG, bytearray([meas]))
+        contr = self._getContr(gain)
+        self.i2c.writeto_mem(ALS_I2CADDR, ALS_CONTR_REG, bytearray([contr]))
+
+        measrate = self._getMeasRate(integration, rate)
+        self.i2c.writeto_mem(ALS_I2CADDR, ALS_MEAS_RATE_REG, bytearray([measrate]))
+
         time.sleep(0.01)
 
-    def _concat_hex(self, a, b):
-        sizeof_b = 0
-        while((b >> sizeof_b) > 0):
-            sizeof_b += 1
-        sizeof_b += sizeof_b % 4
-        return (a << sizeof_b) | b
-
-    def lux(self):
-        data0 = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH1_LOW, 1)
-        data1 = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH1_HIGH, 1)
-        data2 = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH0_LOW, 1)
-        data3 = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH0_HIGH, 1)
-        data_reg_CH1 = self._concat_hex(data1[0], data0[0])
-        data_reg_CH0 = self._concat_hex(data2[0], data3[0])
-        return(data_reg_CH0, data_reg_CH1)
+    def _getContr(self, gain):
+        return ((gain & 0x07) << 2) + 0x01
+
+    def _getMeasRate(self, integration, rate):
+        return ((integration & 0x07) << 3) + (rate & 0x07)
+
+    def _getWord(self, high, low):
+        return ((high & 0xFF) << 8) + (low & 0xFF)
+
+    def light(self):
+        ch1low = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH1_LOW, 1)
+        ch1high = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH1_HIGH, 1)
+        data1 = int(self._getWord(ch1high[0], ch1low[0]))
+
+        ch0low = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH0_LOW, 1)
+        ch0high = self.i2c.readfrom_mem(ALS_I2CADDR , ALS_DATA_CH0_HIGH, 1)
+        data0 = int(self._getWord(ch0high[0], ch0low[0]))
+
+        return (data0, data1)