I don't get it, maybe I am missing something. Can you give an example?
What I have tried is below:
11000011 11100010 00000111 00000001 00000101 00000000 00000001 00000000 00000000 00001100 00000000 10000000 11011101
195 226 7 1 5 0 1 0 0 12 0 128 221
575 % 256 = 63 00111111
11000000
11000011 11110010 00000111 00000001 00000101 00000000 00000001 00000000 00000000 00001100 00000000 10000000 11000011
195 242 7 1 5 0 1 0 0 12 0 128 195
591 % 256 = 79 01001111
I tried to sum the different bytes and then mod the sum with 256 with no luck.
I also tried to inverse the payload or/and the checksum still no luck.