Temp gauge re-code

[Overboost]

Originally Posted by oldskewel

Pardon my ignorance here. Just trying to learn, and am interested in this...

How can it be that you are not changing the checksum when you change other values. I thought maybe if the multiple changes were symmetric they might offset and the checksum would remain unchanged, but that does not appear to be the case with the new temperatures you chose. What obvious feature am I not understanding? Thanks.

We aren't changing any of the arrangement of the bytes in the lines of code, just the temperature values the angles of the gauge uses. We are simply changing the hexadecimal values that relate to temperature according to the gauge angle. The first byte dictates how many bytes in the line. The second byte is the first angle of the gauge, the third byte is the temp value for the first angle, the 4th byte is the second angle, the 5th is that temp value displayed on the second angle, etc.

So for 15ºC and below, the gauge is at the bottom. From 15ºC - 50ºC, it moves from ø0º to 31º; from 50 to 75ºC, it moves towards ø90º. From 75º-115ºC it stays at that angle. From 115 to 124ºC it gets to ø148º, and then 125ºC onward it jumps to ø164º.

15ºC - ø0; 60ºC - ø31; 85ºC - ø90; 95ºC - ø90; 110ºC - ø148; 115ºC - ø164

The 22 page thread I posted from E46F is a good read that explains everything in detail.