Negative Temperatures are not read correctly

[schmiegelt]

Negative Temepratures are read as a very high positive temperature.

[add30417]

#3 I found a solution, maybe you can accept my Pull requests.

[erwinm9m]

convert as follows

def int_from_bytes(b):
if not b: # special-case 0 to avoid b[0] raising
return 0
n = b[0] & 0x7f # skip sign bit
for by in b[1:]:
n = n * 256 + by
if b[0] & 0x80: # if sign bit is set, 2's complement
bits = 8*len(b)
offset = 2**(bits-1)
return n - offset
else:
return n

def getTemperature(lowByte, highByte):
return 0.1*int_from_bytes(bytearray([highByte,lowByte]))