[Solution found with the major help of Riva See page 3]
If someone is willing to join the battle: I am trying to decode the signals from an old temp/humidity sensor that was bought with a Bresser 7002000 "4cast LX" weather station that ceased to work.
The sensor is sending on 433MHz, the encoding seems to be
Long-short: 0
Short-long: 1
With that, I get the following data:
16:15:41 PWM 0000000000000001100010000101101100111000101111001011010101011000 20,0 53
16:17:10 PWM 0000000000000001100010000100001000010100101111110011010110001000 20,3 52
16:18:39 PWM 0000000000000001100010000111001000010100101111010011010111001000 20,6 51
16:20:08 PWM 0000000000000001100010000101101000010100101111100011010110101000 20,8 50
16:21:37 PWM 0000000000000001100010000100011000010100101111000011010101011000 21,1 49
16:23:06 PWM 0000000000000001100010000110001100010100101111100110010101011000 21,3 48
16:24:35 PWM 0000000000000001100010000111001100010100101111000110010110011000 21,5 48
16:26:04 PWM 0000000000000001100010000110101100010100101111000110010111111000 21,7 47
16:27:33 PWM 0000000000000001100010000111101100010100101111111010010101001000 21,9 47
16:32:00 PWM 0000000000000001100010000110001010010100101111101010010110101000 22,2 44
16:33:29 PWM 0000000000000001100010000101001010010100101111001010010111101000 22,3 44
16:34:58 PWM 0000000000000001100010000111001010010100101111001010010101101000 22,4 43
16:36:27 PWM 0000000000000001100010000100101010010100101111110010010101101000 22,4 43
16:37:56 PWM 0000000000000001100010000100101010010100101111110010010101101000 22,5 42
16:39:25 PWM 0000000000000001100010000110101010010100101111010010010101101000 22,6 42
16:40:54 PWM 0000000000000001100010000101101010010100101111010010010110101000 22,6 41
16:42:23 PWM 0000000000000001100010000101101010010100101111100010010101101000 22,6 41
16:43:52 PWM 0000000000000001100010000101101010010100101111100010010101101000 22,7 41
16:45:21 PWM 0000000000000001100010000111101010010100101111100010010111101000 22,8 40
The digits at the end give the temperature in °C and relative humidity in % that the sensor displayed at the time the data was captured.
I would think the leading "00000..." sequence may be a lead-in, the data proper seems to start after the "11000100001" sequence.
Some parts seem to be constant throughout all messages:
0000000000000001100010000111101010010100101111100010010111101000
There are some more bits in between that do not change, but that may be caused by the sensor data being in a narrow temperature and humidity range at the time.
I dug the Internet for hours to find any clue, but none of my findings seem to match.
Neither BCD nor binary patterns are to be found that would even come close to the readable sensor data. I am at a loss currently, I am afraid.