Understanding FM modulated .sub files

Hello, I just joined the community.

After reading trough the forum I understand AM modulated READ RAW .sub files fine… I think.

The file essentially represents a square wave. Peaks = transmit carrier frequency, dips = no transmission. (Although I don’t know how it could determine between OOK and ASK if it’s from READ RAW, without saving the actual waveform.)

However, with an FM modulated signal (saved via READ RAW), how does the .sub contents differentiate between a 10hz increase in carrier signal frequency, 20hz, 50hz, etc. Doesn’t there have to be a way to convey that information in a .sub file for retransmitting?

Am I understanding this wrong? Any insight is appreciated. I tried searching around for answers on this and couldn’t find much, so if this has been answered already please point me in the right direction.

Thanks!

All the RF modulation/demodulation is done by CC1101, so you should look up its datasheet.

1 Like

Thank you.