Remote signals not found on any frequency/modulation

Sub-GHz
#1

I have an old remote controlled ceiling fan of the brand “Casafan”.

I cannot find any specific model name. Also the model isn’t produced anymore and it’s impossible to find any information (or even mentions) online. But it’s not so much about the specific device and more about explaining my findings.

I wanted to scan the remote with the sub-GHz scanner and flipper d.id not show any signal. I’ve the tested every possible combination of frequency and modulation offered by the 0.86.2 firmware, which is 300-915MHz and the modulations AM270, AM650, FM238 and FM476, but still nothing. The frequency analyzer also yielded no result.

What does it mean if you don’t find anything at all? Is it possible that the remote uses a completely different technique. I don’t think there are too many possible technology choices here, are there? Or are there different frequencies and modulations in other parts of the world (my Region is DE).

#2

If the Frequency Analyzer isn’t show anything during key press on the remote, there are three possibilities:

a. not SubGHz, maybe 2,4GHz?
b. not SubGHz, maybe below 300MHz?
c. Not RF?

It would be helpful to have anything more than a brand name. Maybe a photo or the text that it is printed on the remote or behind the battery.

#3

Google for Casafan shows a lot of 433 based remotes that might overlap yours, did you try it in rawrecording and/or frequency analyzer to see if it is on 443 ? from there finding out if it is a rolling code or not should give some answers.

#4

This is the exact issue I had with a device. After wasting too much time I managed to pull up the documentation.

#5

I think, I figured it out.
I took the remote apart to post a picture of the inside, and noticed an IC wit the caption “A7105”. According to online documentations, this is a 2.4 GHz transciever. So, mistery solved, the frequency was simply outside flipper’s range.
I didn’t know that remotes (which don’t communicate over wifi) use such high frequencies. Are there any advantages over sub-GHz frequencies for them?

#6

I don’t see any significant advantage for remote controls like these. A higher frequency let’s you send data more quickly but for sending single button presses it’s the equivalent of mailing a postcard in a shoe box. Lower frequencies can travel farther so there is an advantage to low frequencies. I think it’s just an unusual manufacturing decision.

#7

I tend to regard it as an attempt to use cutting edge technology - even when there is no good reason. Magstripe to iButton to RFID to NFC, 30MHz to 433 to 2.4GHz to 5, plastic cards to mobile apps, etc.

Now you have 15 competing standards

as we all know…

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