Repo of no-std crates for my personal embedded projects
sachy.dev
1/// Calculate the CRC8 checksum.
2///
3/// Implementation based on the reference implementation by Sensirion.
4#[inline]
5pub(crate) const fn crc8(data: &[u8]) -> u8 {
6 const CRC8_POLYNOMIAL: u8 = 0x31;
7 let mut crc: u8 = u8::MAX;
8 let mut i = 0;
9
10 while i < data.len() {
11 crc ^= data[i];
12 i += 1;
13
14 let mut c = 0;
15 while c < 8 {
16 c += 1;
17 if (crc & 0x80) > 0 {
18 crc = (crc << 1) ^ CRC8_POLYNOMIAL;
19 } else {
20 crc <<= 1;
21 }
22 }
23 }
24
25 crc
26}
27
28#[cfg(test)]
29mod tests {
30 use super::*;
31
32 /// Test the crc8 function against the test value provided in the
33 /// SHTC3 datasheet (section 5.10).
34 #[test]
35 fn crc8_test_value() {
36 assert_eq!(crc8(&[0x00]), 0xac);
37 assert_eq!(crc8(&[0xbe, 0xef]), 0x92);
38 }
39}