I am using a dht11 sensor and get the raw bits, where the first 8 Bits are the integral of humidity and following 8 bit the decimals of the humidity. The next 8 Bits are the the integral of temperature, followed by 8 bit decimals of the temperature. In the end there is a 8 bit checksum.
I read some datasheets, but could not find any information about how the decimals have to be read.
Does anyone know if it is a simple fixed-point 8 Bit decimals or do I have to do it differently?
Any help is appreciated
From the dht11 datasheet, only positive values for humidity and temperature can be returned, so no bit reserved for the sign. This is a Q8.8 fixed point representation (see also https://en.wikipedia.org/wiki/Q_(number_format)). To translate from the representation to the physical value you have to divide by 2^8, where 8 is the number of fractional bits. So for example:
0000 0010 1000 0000 = 640 decimal
640/256 = 2.5 decimal