i am struggling since a long time to determine the checksum of the following sequences. I have two examples.  Ex1: Have the same checksum and one have a payload incrementation  by 0x0Aat the same position (Byte 8).Ex2: This one have the same checksum (9.byte).I am sure this are the checksum and is always 1 Byte.What I noticed is that the values of checksum is not bigger than 0x7F.I have many expamples but i see that it never grows up to 0x80.It can also not 0xFF because 0xFF marks the sequenze as the end.Example with paylod increment of 0x0A on the 8.Byte.01: ED  0   1   0   1   0   0   00  2902: ED  0   1   0   1   0   0   0A  1903: ED  0   1   0   1   0   0   14  4904: ED  0   1   0   1   0   0   1E  7905: ED  0   1   0   1   0   0   28  4A06: ED  0   1   0   1   0   0   32  44This examples has the same checksum (0x53):01: E4  09  01  02  26  50  00  5302: E4  10  01  01  00  0F  00  5303: E4  14  01  09  42  09  41  5304: E4  15  01  14  48  08  03  5305: E4  01  02  21  02  50  00  5305: E4  01  02  22  22  52  00  5306: E4  01  02  22  31  05  00  5307: E4  02  02  02  10  0D  05  53I have tested various algorythms.Fletcher, Adler32, BSD 8Bit are one of them.Xor8 an some tests with shiftet bits and various modulus.I have xored the values but nothing of worth comes out.Reveng gave me some results but not for all sequences.I am also sure that it is not a CRC but only a simple checksum.I have read many threads if there was a hint how i can reverse the checksum.But i see nothing wich handles 7bit. I also look at the bits but i dont know on how to begin.I see some participations but dont see the relation.In the first block I see that the checksum is ending in 0x09. (Set 1 - 4)If the payload increases by 0x0A the checksum also increments by 0x30 (Set 2-4)until a specific point (Set 5).I am sure it is very simple. In german i would say ich sehe den Wald vor lauter Bumem nicht.Don't know the correct translation in english. ;-)It would very appreciate if someone can point me the right direction.With best regardsChrisEdit:- replaced the word crc in the text by checksum for better understanding.  Tnx to JimmyB for the hint.
Need help for an unknown 7-bit checksum
crc