This weather station is sold with one remote sensor and a base station capable of monitoring airpressure. It also have a radio controlled clock.
The remote sensor is capable of measuring temperature and pressure and broadcast this information on the 433 MHz band.
Using a 433 MHz receiver together with a logic analyzer several things could be learned:
The sensor transmit 20 bits of information starting with a 1.45 ms pulse followed by 1.50 ms silence. Pulses 2.16 ms long followed by 0.77 ms silence is '1', and 0.70 ms pulses followed by 2.23 ms silence is representing '0'.
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| Channel 2, -16.6C, 20% humidity |
Several different measurements obtained with varying temperatures and constant humidity (36% (0b100100)) showed that the sensor transmitted the humidity in the seven last bits of the transmission.
The last seven bits is arranged in the following fashion: bit 1, 0 , 6, 5, 4, 3 and 2.
Yeah, and after some googling I found that the decoded signals were presented at telldus.com.
In the following table this decoding is used with the exception of me rotating the bitorder.
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