Today John Lee sent me a nice link to a scooter hacking forum. The short of it is I got a nice hint to how the data structure is built. The last byte of the data packet is CRC-8 Maxim. So to alter any packet to test other configs on the scooter you have to calculate the CRC byte for the end.
Here are some test examples I made from the know packets that I have.
Polynomial Calculator
Data input: A612021014
Results
Algorithm |
Result |
Check |
Poly |
Init |
RefIn |
RefOut |
XorOut |
CRC-8/MAXIM |
0xCF |
0xA1 |
0x31 |
0x00 |
True |
True |
0x00 |
Data input: A612021514
Results:
Algorithm |
Result |
Check |
Poly |
Init |
RefIn |
RefOut |
XorOut |
CRC-8/MAXIM |
0x30 |
0xA1 |
0x31 |
0x00 |
True |
True |
0x00 |
Data input: A612021114
Results:
Algorithm |
Result |
Check |
Poly |
Init |
RefIn |
RefOut |
XorOut |
CRC-8/MAXIM |
0x0B |
0xA1 |
0x31 |
0x00 |
True |
True |
0x00 |
So I can now build a CRC calculation function and create new packets to test there different Hex numbers and there functions.
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