What is the modulation used in a Honda Civic keyfob? And how can you find this out?
I'm using a Flipper Zero which and I want to decode my unlock signal which is rolling. The FCC ID of the keyfob is N5F-A05TAA. I had calculated independently and later confirmed that the keyfob transmits on 313.85 mhz. How do I demodulate that signal? How do I find the modulation used? Many people seem to claim it's in the database at fccid.io, but as linked above I don't see it.
I've brute forced all the modulations available on the Flipper Zero, and I don't see a successful demodulation of a single signal under "Read". I'm using the Flipper Unleashed firmware.
According to one datasheet the modulation seems to be FSK (which Wikipedia says is Frequency-shift keying). But that's not available on the Flipper Zero, it just has HND, Pagers, FM{15k, 95, 476, 238,}, AM{650, 270},
- It seems Flipper Unleashed "custom presets" for FM95, FM15K, Pagers, and HND. defined in subghz.c. None of these presets worked.
- The expanded names of the other modulations can also be found in
subghz.c. This makes me think the "FM" means FSK. But having tested it none of the FM modulations worked.
I found the rtl 433 project, which claims it can decode Honda Keys, it seems it's using a preset called FSK_PULSE_PWM.
