Updated LIS2HH12 for scale

Author: Alex Bucknall

pysense/lib/LIS2HH12.py

@@ -15,7 +15,9 @@ class LIS2HH12:
     ACC_Z_L_REG = const(0x2C)
     ACC_Z_H_REG = const(0x2D)
 
-    def __init__(self, pysense=None, sda='P22', scl='P21'):
+    SCALE = const(8192)
+
+    def __init__(self, pysense = None, sda = 'P22', scl = 'P21'):
         if pysense is not None:
             self.i2c = pysense.i2c
         else:
@@ -30,27 +32,31 @@ def __init__(self, pysense=None, sda='P22', scl='P21'):
 
         whoami = self.i2c.readfrom_mem(ACC_I2CADDR , PRODUCTID_REG, 1)
         if (whoami[0] != 0x41):
-            raise ValueError("Incorrect product ID")
+            raise ValueError("Incorrect Product ID")
+
         # enable acceleration readings
         self.i2c.readfrom_mem_into(ACC_I2CADDR , CTRL1_REG, self.reg)
-        self.reg[0] &= ~0x70
-        self.reg[0] |= 0x30
+        self.reg[0] &= ~0b01110000
+        self.reg[0] |= 0b00110000
         self.i2c.writeto_mem(ACC_I2CADDR , CTRL1_REG, self.reg)
+
         # change the full-scale to 4g
         self.i2c.readfrom_mem_into(ACC_I2CADDR , CTRL4_REG, self.reg)
         self.reg[0] &= ~0b00110000
         self.reg[0] |= 0b00100000
         self.i2c.writeto_mem(ACC_I2CADDR , CTRL4_REG, self.reg)
-        self.read()
 
-    def read(self):
+        # make a first read
+        self.acceleration()
+
+    def acceleration(self):
         x = self.i2c.readfrom_mem(ACC_I2CADDR , ACC_X_L_REG, 2)
         self.x = struct.unpack('<h', x)
         y = self.i2c.readfrom_mem(ACC_I2CADDR , ACC_Y_L_REG, 2)
         self.y = struct.unpack('<h', y)
         z = self.i2c.readfrom_mem(ACC_I2CADDR , ACC_Z_L_REG, 2)
         self.z = struct.unpack('<h', z)
-        return (self.x[0], self.y[0], self.z[0])
+        return (self.x[0] / SCALE, self.y[0] / SCALE, self.z[0] / SCALE)
 
     def roll(self):
         div = math.sqrt(math.pow(self.y[0], 2) + math.pow(self.z[0], 2))