Decoding Altronics X7064 temp/hum sensor

[TomW1605]

hi

i have several saved signal files from a temp sensor i bought. it has next to no markings on it and i can't tell if it is a rebrand of a standard chinese model.

i honestly have no idea where to start with processing them. it looks like they are detected reliably and consistently so the files should be clean.

i have viewed the samples in waveform analysers but i don't know where to go from there. i have attached the samples if someone can help or if you can point me in the right direction.

samples.zip
waveform of one of the samples:

[zuckschwerdt]

The spectrogram looks like heavy aliasing, but the demod actually works fine and results in nice pulses.
Write the files to .ook (works for FSK too): rtl_433 -w g016_433.92M_250k.ook g016_433.92M_250k.cu8
Then throw those pulse files onto https://triq.org/pdv/ and figure out the coding. The intro at https://triq.org/rtl_433/PULSE_FORMATS.html might be some help.

[zuckschwerdt]

Looks like each transmission has 3 repeats (e.g. g017 has two transmissions). The coding is not something I recognize.
With a PCM slicing of 90 µs you can get the raw pulse data, but that looks too regular and too much data for a temperature sensor. Symbols must be wider that 90 µs.
Then maybe copy a good code of each transmission out of pdv (break the three apart roughly and compare), put the codes in a BitBench and see if you spot a pattern in the changes of codes.

[TomW1605]

it does do humidity as well so there is more than temp data but probably not much more.

i have gotten the 2 from g17 into BitBench and played around a bit but im not realy sure what i am aiming for. i also stuck them in a text comparison and there are only a few (7) pairs that are diffrent. i do thing there was an extra 1 between the 2 signals though. not sure what thats about but i had to remove it for them to line up with the preamble stuff.

[TomW1605]

ok so i have worked with 5 samples and i think i know what part is the humidity. i think the 18th pair is the humidity (2A, 2B, 3B, 3A and 3A in the samples below).

in the below samples the top 2 i recorded and noted the reading from the sensor. they were 42% and 43% respectively. that makes the other 3 have around 50% humidity and that matches pretty well with my home assistant records from the time.

what im not sure about is how to now get this info out of the signal and into a format that is usable. i also havnet worked out where the temp is but i assum that is because it is a decimal so it will be more complex.

FF FF AA AA AA AA AA CA CA 54 AA A1 6E 91 A6 8A AC 2A AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA 96 AA 00 03 FF FF F5 55 55 55 55 59 59 4A 95 54 2D D2 34 D1 55 85 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 52 D5 40 00 7F FF FE AA AA AA AA AB 2B 29 52 AA 85 BA 46 9A 2A B0 AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA 5A A8 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0
FF FF AA AA AA AA AA CA CA 54 AA A1 6E 95 A6 9A AF 2B AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AE AA 00 03 FF FF F5 55 55 55 55 59 59 4A 95 54 2D D2 B4 D3 55 E5 75 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 D5 40 00 7F FF FE AA AA AA AA AB 2B 29 52 AA 85 BA 56 9A 6A BC AE AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA BA A8 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0
FF FF AA AA AA AA AA CA CA 54 AA A1 AA 55 A6 BA A5 3B AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA D0 AA 00 03 FF FF F5 55 55 55 55 59 59 4A 95 54 35 4A B4 D7 54 A7 75 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 5A 15 40 00 7F FF FE AA AA AA AA AB 2B 29 52 AA 86 A9 56 9A EA 94 EE AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AB 42 A8 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0
FF FF AA AA AA AA AA CA CA 54 AA A1 AA 55 A6 CA A0 3A AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA DA AA 00 03 FF FF F5 55 55 55 55 59 59 4A 95 54 35 4A B4 D9 54 07 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 5B 55 40 00 7F FF FE AA AA AA AA AB 2B 29 52 AA 86 A9 56 9B 2A 80 EA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AB 6A A8 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1
FF FF AA AA AA AA AA CA CA 54 AA A1 AA 51 A6 CA A0 3A AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA D6 AA 00 03 FF FF F5 55 55 55 55 59 59 4A 95 54 35 4A 34 D9 54 07 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 5A D5 40 00 7F FF FE AA AA AA AA AB 2B 29 52 AA 86 A9 46 9B 2A 80 EA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AB 5A A8 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0

[zuckschwerdt]

If you use something like ffffaaaaaaaaaacaca as a preamble match and break the lines at the 00 runs you get this BitBench.

That's already gives a good idea about the format.

Since we don't see long runs of 0's we can limit the allowed gap to break automatically and also find and align on the (assumed) preamble:
rtl_433 -X 'n=name,m=FSK_PCM,s=90,l=90,g=800,r=9000,preamble=ffffaaaaaaaaaacaca'

Can you use that to grab a range of codes with a known progression of values (e.g. a slow warm up or cool down)?

[zuckschwerdt]

Oh, I see. the preamble is actually ffffaaaaaaaaaacaca54 (or some rightmost part of it). That then leaves the remaining 31 bytes to add to byte 32, see this BitBench.

[TomW1605]

i think you are at least right about the aaa1 being the id. when i switch the "channel" switch that changes to aaa2 and aaa3 for "channel" 2 and 3 respectively

[TomW1605]

ok got 1 more reading for a diffrent humidity and it matches in the signal. so im pretty confident with that part too.

[TomW1605]

im going to turn on the AC and try and cool the room a bit to get some more temp readings

[TomW1605]

ok got 20 data points. also i think this temp sensor is a bit inacurate, my other temp sensor says it is about 23°C not the 25°C this says it is

temp	humidity	code
27.6	42	ffffaaaaaaaaaacaca54aaa16e91a6baa62aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac0aa0003fffff55555555559594a95542dd234d754c55555555555555555555555555555555555555555555555581540007ffffeaaaaaaaaab2b2952aa85ba469aea98aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab02a80000000000000000000000000
27.7	42	ffffaaaaaaaaaacaca54aaa16e91a6baa82aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac2aa0003fffff55555555559594a95542dd234d755055555555555555555555555555555555555555555555555585540007ffffeaaaaaaaaab2b2952aa85ba469aeaa0aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab0aa80000000000000000000000000
27.8	41	ffffaaaaaaaaaacaca54aaa16e91a6baa929aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac2aa0003fffff55555555559594a95542dd234d755253555555555555555555555555555555555555555555555585540007ffffeaaaaaaaaab2b2952aa85ba469aeaa4a6aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab0aa80000000000000000000000000
27.8	41	ffffaaaaaaaaaacaca54aaa16e91a6baaa29aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac3aa0003fffff55555555559594a95542dd234d755453555555555555555555555555555555555555555555555587540007ffffeaaaaaaaaab2b2952aa85ba469aeaa8a6aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab0ea80000000000000000000000000
27.7	41	ffffaaaaaaaaaacaca54aaa16e91a6baa829aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac1aa0003fffff55555555559594a95542dd234d755053555555555555555555555555555555555555555555555583540007ffffeaaaaaaaaab2b2952aa85ba469aeaa0a6aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab06a80000000000000000000000000
27.6	40	ffffaaaaaaaaaacaca54aaa16e91a6baa528aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabdaa0003fffff55555555559594a95542dd234d754a5155555555555555555555555555555555555555555555557b540007ffffeaaaaaaaaab2b2952aa85ba469aea94a2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaf6a80000000000000000000000000
27.4	40	ffffaaaaaaaaaacaca54aaa16e91a6baa228aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabaaa0003fffff55555555559594a95542dd234d754451555555555555555555555555555555555555555555555575540007ffffeaaaaaaaaab2b2952aa85ba469aea88a2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaeaa80000000000000000000000000
27.2	40	ffffaaaaaaaaaacaca54aaa16e91a6aaaf28aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab7aa0003fffff55555555559594a95542dd234d555e5155555555555555555555555555555555555555555555556f540007ffffeaaaaaaaaab2b2952aa85ba469aaabca2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaadea80000000000000000000000000
27	40	ffffaaaaaaaaaacaca54aaa16e91a6aaab28aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab3aa0003fffff55555555559594a95542dd234d555651555555555555555555555555555555555555555555555567540007ffffeaaaaaaaaab2b2952aa85ba469aaaaca2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaacea80000000000000000000000000
26.8	41	ffffaaaaaaaaaacaca54aaa16e91a6aaa829aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab1aa0003fffff55555555559594a95542dd234d555053555555555555555555555555555555555555555555555563540007ffffeaaaaaaaaab2b2952aa85ba469aaaa0a6aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac6a80000000000000000000000000
26.7	40	ffff2aaaaaaaaacaca54aaa16e91a6aaa528aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaadaa0003fffff55555555559594a95542dd234d554a5155555555555555555555555555555555555555555555555b540007ffffeaaaaaaaaab2b2952aa85ba469aaa94a2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab6a80000000000000000000000000
26.5	40	ffffaaaaaaaaaacaca54aaa16e91a6aaa228aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa0003fffff55555555559594a95542dd234d554451555555555555555555555555555555555555555555555555540007ffffeaaaaaaaaab2b2952aa85ba469aaa88a2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa80000000000000000000000000
26.3	40	ffff2aaaaaaaaacaca54aaa16e91a69aaf28aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa7aa0003fffff55555555559594a95542dd234d355e5155555555555555555555555555555555555555555555554f540007ffffeaaaaaaaaab2b2952aa85ba469a6abca2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa9ea80000000000000000000000000
26.3	40	ffff2aaaaaaaaacaca54aaa16e91a69aae28aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa6aa0003fffff55555555559594a95542dd234d355c5155555555555555555555555555555555555555555555554d540007ffffeaaaaaaaaab2b2952aa85ba469a6ab8a2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa9aa80000000000000000000000000
26.2	40	ffffaaaaaaaaaacaca54aaa16e91a69aac28aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4aa0003fffff55555555559594a95542dd234d355851555555555555555555555555555555555555555555555549540007ffffeaaaaaaaaab2b2952aa85ba469a6ab0a2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa92a80000000000000000000000000
26.1	40	ffffaaaaaaaaaacaca54aaa16e91a69aab28aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa3aa0003fffff55555555559594a95542dd234d355651555555555555555555555555555555555555555555555547540007ffffeaaaaaaaaab2b2952aa85ba469a6aaca2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa8ea80000000000000000000000000
25.9	40	ffffaaaaaaaaaacaca54aaa16e91a69aa728aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa9faa0003fffff55555555559594a95542dd234d354e5155555555555555555555555555555555555555555555553f540007ffffeaaaaaaaaab2b2952aa85ba469a6a9ca2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa7ea80000000000000000000000000
25.9	40	ffffaaaaaaaaaacaca54aaa16e91a69aa728aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa9faa0003fffff55555555559594a95542dd234d354e5155555555555555555555555555555555555555555555553f540007ffffeaaaaaaaaab2b2952aa85ba469a6a9ca2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa7ea80000000000000000000000000
25.8	41	ffff2aaaaaaaaacaca54aaa16e95a69aa629aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa3aa0003fffff55555555559594a95542dd2b4d354c53555555555555555555555555555555555555555555555547540007ffffeaaaaaaaaab2b2952aa85ba569a6a98a6aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa8ea80000000000000000000000000
25.8	41	ffffaaaaaaaaaacaca54aaa16e91a69aa629aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa9faa0003fffff55555555559594a95542dd234d354c5355555555555555555555555555555555555555555555553f540007ffffeaaaaaaaaab2b2952aa85ba469a6a98a6aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa7ea80000000000000000000000000

BitBench Link

[TomW1605]

some of them have an error in the first repeat. i assume that is why they send it all 3 times

[zuckschwerdt]

So with some cleanup and removing dups we get this BitBench. The layout is strange but the temp seems to be a hex value with 0.1 C resolution. But there must be more bits for very high and low temperatures.

[TomW1605]

that dosnt look right. many of the signals with the same display temp have a temp signal that is 1 off from each other
eg the last 2 are both 27.8°C but one has TEMP?b9 and the other has TEMP?ba

also i assume you are only looking at 1 of the repeats per signal here right?

[zuckschwerdt]

What you see are rounding errors in the display. Do a regression. It's C = 0.056 x T + 17.4, which works nicely but looks odd. This points to F as unit, where F = 0.1 x T + 63. Just add 630 to the raw value and you get deci-F.

The repeats are all identical.

[TomW1605]

so take the b9, convert it to decimal, add 630, divide by 10 then convert to Celsius?

am i understanding that right?

also why b9? that is the first and last digit of the data section. seams like an odd way to do it. how did you pick up on that?