eculocate

commit 2715d452324c72cd8f0e60a82e0d27e3d09bef7e
parent db3535f2ebf8fc42592bc14f5d88ffbc8545acbc
Author: Daniel Barlow <dan@telent.net>
Date:   Sat, 22 Nov 2025 15:11:16 +0000

simplify checksum calc

0 - (a + b + c ...) == 0 - a - b - c ...

Diffstat:
M
src/ecu.rs
 | 
3
+--

1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/src/ecu.rs b/src/ecu.rs
@@ -35,9 +35,8 @@ impl Ecu<'_> {
 	let last = bytes.len() - 1;
 	let mut sum : u8 = 0;
 	for b in &bytes[0..last] {
-	    sum = sum.wrapping_add(*b);
+	    sum = sum.wrapping_sub(*b);
 	}
-	sum = 0u8 - sum;
 	let is_correct = sum == bytes[last];
 	bytes[last] = sum;
 	is_correct