Help in interpreting the signal from OBH Oven Thermometer

[OleStauning]

I am trying to figure out how to read the temperature sent by my OBH oven thermometer (see http://www.obhnordica.se/Files/Filer/Userguides/4775.pdf).

Could you please help me in interpreting the output (http://pastie.org/9098436) that I get when running the command "./rtl_433 -f 433892400 -a -l 3000"? - the receiver says the temperature is constant; 24 degrees celcius.

Your feedback is greatly appreciated.

[merbanan]

You have to get several readings and vary the temperature. Then we can try to figure out how the temperature is encoded.

[OleStauning]

Thanks for your answer.

I have done several measurements:

1. Moving temperature in the interval 17-54 degrees celcius (http://pastie.org/9115662),
2. Pressing reset button on sender while keeping the temperature constant (http://pastie.org/9115666),
3. Pressing reset button on sender while the sensor is unplugged (http://pastie.org/9115668).

A transmission always starts with "ff ff 49 6d 64 f3" followed by 18 nibbles, ABCDEFGHIJKLMNOPQR. All nibbles, except R, contains at least one "1". A transmission is always repeated.

AB changes every time "reset" on the sender is pressed. It seems that CDEFGHIJKLMN contains data which is somehow scrambled with AB. By keeping the temperature constant or taking out the sensor I can see that several AB values map to the same data bytes. Example; AB=10010101, 01101001, 00101011 maps to the same value CD=00111100 when the sensor is not plugged in.

OPQR seems to loop through some sequence.

I'm sure the scrambling can be easily broken and the temperature can be decoded. Just need more time - or some help.

[cmadsen]

I got a few readings from the same sensor here
28
[00] {114} ff ff 49 6d 64 f3 37 be ad 9f f3 24 d7 ff 40 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111110 10101101 10011111 11110011 00100100 11010111 11111111 01000000
[01] {114} ff ff 49 6d 64 f3 37 be ad 9f f3 24 d7 ff 40 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111110 10101101 10011111 11110011 00100100 11010111 11111111 01000000
27
[00] {116} ff ff 49 6d 64 f3 37 bd 6d 9f 93 93 2b fe 60 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111101 01101101 10011111 10010011 10010011 00101011 11111110 01100000
[01] {116} ff ff 49 6d 64 f3 37 bd 6d 9f 93 93 2b fe 60 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111101 01101101 10011111 10010011 10010011 00101011 11111110 01100000
26
[00] {115} ff ff 49 6d 64 f3 37 bf 35 9f 93 9b ab fc e0 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111111 00110101 10011111 10010011 10011011 10101011 11111100 11100000
[01] {115} ff ff 49 6d 64 f3 37 bf 35 9f 93 9b ab fc e0 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111111 00110101 10011111 10010011 10011011 10101011 11111100 11100000
26
[00] {112} ff ff 49 6d 64 f3 37 bd 75 9f e7 3b df fb 00 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111101 01110101 10011111 11100111 00111011 11011111 11111011 00000000
[01] {112} ff ff 49 6d 64 f3 37 bd 75 9f e7 3b df fb 00 : 11111111 11111111 01001001 01101101 01100100 11110011 00110111 10111101 01110101 10011111 11100111 00111011 11011111 11111011 00000000

[merbanan]

Long time no answer, can some one of you send the resulting files when running with rtl_433 -a -t ?

[merbanan]

Without any sample signals and matching temperatures nothing more can be done. Closing issue,