I am working on determining the format of an OOK transmitted sensor. I have captured the transmission on an oscilloscope and now need to convert it to binary to determine the format of the packet.
I want to make sure I am doing this right. I have captured 10 transmissions, and none of them are identical. I don't expect them to be identical, but they should be close.
The picture below I read as : 11001111110110
My thinking is that for each cycle of the clock would be one bit.
I think this puts me pretty close. The FCC documents state that the transmission is roughly 9ms and 76 bits long. The 10 packets I have "decoded" are very close to that, 72-78 bits long. They should all be the same length, but I am thinking that maybe the CC1101 might have some wakeup lag on the preamble part. Here are the 10 decoded binary packets using the above method. (Non-inverted, so when data goes high, = binary 1)
1111 1001 0101 0000 0101 0100 1000 1000 0001 0001 0100 0001 1001 1110 0000 0010 0100 0100 01
1100 0000 0000 1100 0010 1010 0100 0100 0000 0000 0000 0000 0010 0100 1010 1000 0000 1000 0011
1110 0001 0101 0000 0101 0100 1100 1100 0011 0010 0000 0011 0101 1000 1011 1110 1100 1001 00
1100 0001 0101 0011 1101 0110 1100 1100 0011 1110 0110 1101 1011 1110 1100 1101 0110 1101 101
1100 1111 0101 1011 1101 0110 1100 1100 1111 1110 1100 1101 1011 0101 0110 1101 0110 1010 11
1100 0011 1010 1101 1110 1011 0110 0110 0011 1110 1101 0111 1011 0100 0111 1111 1010 1110 001
1111 1001 1011 0011 1101 0110 1101 1101 1111 1111 1110 0001 1011 0110 0101 0111 1101 0110 11101
1111 1111 0101 1011 0101 1001 1011 1010 0000 1011 1111 1101 1011 1101 1111 1101 0110 1101 1
1111 1111 1010 1101 1110 1011 0110 1100 1111 1110 1011 1111 1101 0110 1101 1111 1101 0101 1111
1111 1111 0101 1011 1101 0110 1101 1100 1111 1101 0111 1111 0111 1011 1111 0110 1101 1101 11
So, Any ideas on why I am seeing this much variance in the Serial Output? Am I decoding it right?
