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Checksum should not be calculated with STX #1

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jkirk opened this issue May 13, 2023 · 0 comments · Fixed by #2
Closed

Checksum should not be calculated with STX #1

jkirk opened this issue May 13, 2023 · 0 comments · Fixed by #2
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jkirk commented May 13, 2023

We agreed to calculate the checksum using only the Gauge Code and Gauge Value (and
without STX (0x02)). Currently c172hc-fsmaster still uses STX to calculate the
checksum. I believe this is the code in question:

c172hc-fsmaster/Checksum_SerIn_SOT_EOT_LCD_TOut/Checksum_SerIn_SOT_EOT_LCD_TOut.ino

Lines 283 to 286 in b8b101e

for (int i = 0; i < numReceived - 2; i++)
{
sum += receivedBytes[i]; // add all bytes in Array
}

The sum should start with i = 1. I can provide a PR.
@jkirk jkirk self-assigned this May 13, 2023
@jkirk jkirk added the bug Something isn't working label May 13, 2023
jkirk added a commit that referenced this issue May 13, 2023
@jkirk
Correct Checksum calculation, again
bb7922f 
We have agreed to calculate the checksum using only the Gauge Code and
Gauge Value which basically means that the first byte should be omitted
when calculating the sum.

The checksum is then the 2's complement of the sum of bytes.

Closes: #1
@jkirk jkirk mentioned this issue May 13, 2023
Merged
jkirk added a commit that referenced this issue May 13, 2023
@jkirk
Sum + Checksum should not be calculated with STX
6516b88 
We have agreed to calculate the checksum using only the Gauge Code and
Gauge Value which basically means that the first byte should be omitted
when calculating the sum.

The checksum is then the 2's complement of the sum of bytes.

Closes: #1
SimPilot47 pushed a commit that referenced this issue May 14, 2023
@jkirk
Sum + Checksum should not be calculated with STX
df86c4b 
We have agreed to calculate the checksum using only the Gauge Code and
Gauge Value which basically means that the first byte should be omitted
when calculating the sum.

The checksum is then the 2's complement of the sum of bytes.

Also updated the version string.

Closes: #1
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Sum + Checksum should not be calculated with STX jkirk/c172hc-fsmaster
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