bthome.py simplify packing by using functions

Author: DavesCodeMusings

bthome.py

@@ -17,26 +17,20 @@
 # See "Sensor Data" table at https://bthome.io/format/ for details.
 BATTERY_UINT8 = const(0x01)
 TEMPERATURE_SINT16 = const(0x02)
-_TEMPERATURE_SINT16_SCALING = const(100)
 HUMIDITY_UINT16 = const(0x03)
-_HUMIDITY_UINT16_SCALING = const(100)
 PRESSURE_UINT24 = const(0x04)
-_PRESSURE_UINT24_SCALING = const(100)
 ILLUMINANCE_UINT24 = const(0x05)
-_ILLUMINANCE_UINT24_SCALING = const(100)
 MASS_KG_UINT16 = const(0x06)
-_MASS_KG_UINT16_SCALING = const(100)
 MASS_LB_UINT16 = const(0x07)
-_MASS_LB_UINT16_SCALING = const(100)
 
-# Default value decimal places indicate precision
-device_name = "BTHome-MPY"
-battery = 0         # percent
-temperature = 0.00  # degrees Celsius
-humidity = 0.00     # percent (relative humidity)
-pressure = 0.00     # hectoPascals (millibars)
-illuminance = 0.0   # Lux
-mass = 0.00         # kg or lb
+# Default value decimal places hint at precision
+battery = 0                 # percent
+temperature = 0.00          # degrees Celsius
+humidity = 0.00             # percent (relative humidity)
+pressure = 0.00             # hectoPascals (millibars)
+illuminance = 0.00          # Lux
+mass = 0.00                 # kg or lb
+device_name = "BTHome-MPY"  # Limit to 10 characters
 
 def _pack_device_name():
     assert len(device_name) > 0
@@ -46,22 +40,38 @@ def _pack_device_name():
     device_name_bytes = bytes([len(device_name_bytes)]) + device_name_bytes
     return device_name_bytes
 
+# 8-bit unsigned integer with scaling of 1 (no scaling, 0 decimal places)
+def _pack_uint8_x1(object_id, value):
+    return pack('BB', object_id, value)
+
+# 16-bit signed integer with scalling of 100 (2 decimal places)
+def _pack_sint16_x100(object_id, value):
+    return pack('<Bh', object_id, round(value * 100))
+
+# 16-bit unsigned integer with scalling of 100 (2 decimal places)
+def _pack_uint16_x100(object_id, value):
+    return pack('<BH', object_id, round(value * 100))
+
+# 24-bit unsigned integer with scaling of 100 (2 decimal places)
+def _pack_uint24_x100(object_id, value):
+    return pack('<BL', object_id, round(value * 100))[:-1]
+
 # The BTHome object ID determines the number of bytes and fixed point decimal multiplier.
 def _pack_bthome_data(object_id):
     if object_id == BATTERY_UINT8:
-        bthome_bytes = pack('BB', BATTERY_UINT8, battery)
+        bthome_bytes = _pack_uint8_x1(BATTERY_UINT8, battery)
     elif object_id == TEMPERATURE_SINT16:
-        bthome_bytes = pack('<Bh', TEMPERATURE_SINT16, round(temperature * _TEMPERATURE_SINT16_SCALING))
+        bthome_bytes = _pack_sint16_x100(TEMPERATURE_SINT16, temperature)
     elif object_id == HUMIDITY_UINT16:
-        bthome_bytes = pack('<Bh', HUMIDITY_UINT16, round(humidity * _HUMIDITY_UINT16_SCALING))
+        bthome_bytes = _pack_uint16_x100(HUMIDITY_UINT16, humidity)
     elif object_id == PRESSURE_UINT24:
-        bthome_bytes = pack('<BL', PRESSURE_UINT24, round(pressure * _PRESSURE_UINT24_SCALING))[:-1]
+        bthome_bytes = _pack_uint24_x100(PRESSURE_UINT24, pressure)
     elif object_id == ILLUMINANCE_UINT24:
-        bthome_bytes = pack('<BL', ILLUMINANCE_UINT24, round(illuminance * _ILLUMINANCE_UINT24_SCALING))[:-1]
+        bthome_bytes = _pack_uint24_x100(ILLUMINANCE_UINT24, illuminance)
     elif object_id == MASS_KG_UINT16:
-        bthome_bytes = pack('<Bh', MASS_KG_UINT16, round(mass * _MASS_KG_UINT16_SCALING))
+        bthome_bytes = _pack_uint24_x100(MASS_KG_UINT16, mass)
     elif object_id == MASS_LB_UINT16:
-        bthome_bytes = pack('<Bh', MASS_LB_UINT16, round(mass * _MASS_LB_UINT16_SCALING))
+        bthome_bytes = _pack_uint24_x100(MASS_LB_UINT16, mass)
     else:
         bthome_bytes = bytes()
     print("Packing with data:", bthome_bytes.hex().upper())