I believe this question is on topic for this site under
Algorithm debugging questions, but if not, I would appreciate a suggestion about where to post this question.
I have been messing around with detecting a car key fob that was given to me from a room mate. This key fob goes to a broken car in a junk yard and he got it for free from there. I have managed to figure out how to sort out a car key signal from background noise by filtering based on the decibel level. I am very, very, new to signal processing and I want to learn more. The problem is, I cannot figure out how to make my program tell the difference between button presses and and different car keys.
I have written this program in Python 3 and I use a RTL SDR to detect the key fob. The key, while it is supposed to operate on 315 MHz, it appears to operate on 314,873 MHz. I figured this much out using Gqrx. The Key Fob is a Ford 2S4T-15K601-AA.
I hear some keys use rolling codes and I do not know if this key does. I am not interested in actually cracking any cryptography on this key unless it is necessary to detect which key buttons are pressed.
How would I differentiate between key presses and key fobs?
This is an example of the program receiving the lock button being pressed.
➜ remote git:(master) python3 remote.py Devices: ['00000001'] Found Rafael Micro R820T tuner [R82XX] PLL not locked! Wanted Frequency: 315000000.0 Hz! Actual Frequency: 314873000.0 Hz! Offset: -127000 and Squelch: -10.0 Signal!!! Decibel: -4.172264183610216 Signal:  Signal!!! Decibel: -7.696191692271029 Signal: [1, 1] Signal!!! Decibel: -3.3640835791737893 Signal: [1, 1, 1] Signal!!! Decibel: -4.760667362463348 Signal: [1, 1, 1, 1] Signal!!! Decibel: -7.167746085106671 Signal: [1, 1, 1, 1, 1] Signal!!! Decibel: -3.007769020399573 Signal: [1, 1, 1, 1, 1, 1]