bastian/mywhoosh2garmin
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat: add FIT CRC calculation

Browse Source
This commit is contained in:
Bastian Wagner
2026-08-15 10:21:09 +02:00
parent 49aba8efb4
commit 4599b2b71c
4 changed files with 29 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

0
app/fit/__init__.py Normal file
View File

18
app/fit/crc.py Normal file
View File

@@ -0,0 +1,18 @@
CRC_TABLE = (
0x0000, 0xCC01, 0xD801, 0x1400,
0xF001, 0x3C00, 0x2800, 0xE401,
0xA001, 0x6C00, 0x7800, 0xB401,
0x5000, 0x9C01, 0x8801, 0x4400,
)
def fit_crc(data: bytes | bytearray | memoryview) -> int:
crc = 0
for byte in data:
tmp = CRC_TABLE[crc & 0xF]
crc = (crc >> 4) & 0x0FFF
crc ^= tmp ^ CRC_TABLE[byte & 0xF]
tmp = CRC_TABLE[crc & 0xF]
crc = (crc >> 4) & 0x0FFF
crc ^= tmp ^ CRC_TABLE[(byte >> 4) & 0xF]
return crc & 0xFFFF