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Questions
Since my engine is air cooled, I need the CLT cooleant temperature sensor to measure oil temperatures up to about 120°C. As i was calibrating the NTC resistors for sensors, i was running EasyTherm4.exe .
The generated thermfactor.inc file look like seen below, where ADC values below 17 or temperatures above 215°F (101.7°C)is not represented.
- How do i change the coleant temperature range, so Tbin = Temp in °F , without subtracting 40°F.
- The byte value for the temperature is Tbin = temp in deg. farenhet - 40 this gives maximum temperature Tmax = 255 = 0xFF = 215°F or 101.7°C
- So i thought of changing the Tbin representation to a 1 to 1 representation of temperatures from 0x00 - 0xFF giving 0°F - 255°F or -17.78°C - 123.9°C range.
- So is there an easy way to alter this in the firmware .c files or by config.txt or in my_make ?
- Also thermfactor.inc and matfactor.inc sems to use different failure value, Why ? Is the binary representation the same °F + 40 ?
This is an unfortunate inheritance from megasquirt / megatune. It is a problem for watercooled engines too. The only easy way I can think of is to define your own engine.coolant resolution,
(-40 .. 150C should be enough) and adjust your inc files and coolant related config parameters accordingly. Readings in megatune and LCD will be wrong, although it might not be hard to fix them.
Part of thermfactor.inc file\n
; Generated using EasyTherm4.exe ; ; Citroen Xantia IAT Sensor ; ; File generated for use with stock 2490 ohm resistor at R7 ; ; Steinhart-Hart coefficients: A= 1,533831E-03 B=1,99258E-04 C= 6,960201E-07 ; ; Input Data Temp, degC Resistance ; 0 5000 ; 25 2000 ; 100 190 ; THERMFACTOR: ; ADC Temp, degF DB 210T ; 0 Sensor Failure - use 170 degF as default DB 255T ; 1 442,07 DB 255T ; 2 379,44 DB 255T ; 3 345,56 DB 255T ; 4 322,57 DB 255T ; 5 305,26 DB 255T ; 6 291,43 DB 255T ; 7 279,93 DB 255T ; 8 270,10 DB 255T ; 9 261,54 DB 255T ; 10 253,94 DB 255T ; 11 247,13 DB 255T ; 12 240,95 DB 255T ; 13 235,29 DB 255T ; 14 230,08 DB 255T ; 15 225,25 DB 255T ; 16 220,75 DB 255T ; 17 216,54 DB 253T ; 18 212,57 DB 249T ; 19 208,83 DB 245T ; 20 205,29 DB 242T ; 21 201,92
Part of matfactor.inc file\n
; Generated using EasyTherm4.exe, ; ; NTC from Web Shop ; ; File generated for use with stock 2490 ohm resistor at R4 ; ; Steinhart-Hart coefficients: A= 1,765869E-03 B=1,611974E-04 C= 8,451341E-07 ; ; Input Data Temp, degC Resistance ; 0 5000 ; 24 2020 ; 100 150 ; MATFACTOR: ; ADC Temp, degF DB 100T ; 0 Sensor Failure - 100% applied DB 255T ; 1 379,93 DB 255T ; 2 333,78 DB 255T ; 3 307,89 DB 255T ; 4 289,90 DB 255T ; 5 276,14 DB 255T ; 6 265,00 DB 255T ; 7 255,65 DB 255T ; 8 247,59 DB 255T ; 9 240,50 DB 255T ; 10 234,18 DB 255T ; 11 228,47 DB 255T ; 12 223,26 DB 255T ; 13 218,48 DB 254T ; 14 214,05 DB 250T ; 15 209,93 DB 246T ; 16 206,07 DB 242T ; 17 202,44 DB 239T ; 18 199,02 DB 236T ; 19 195,78 DB 233T ; 20 192,71 DB 230T ; 21 189,78 DB 227T ; 22 186,98 DB 224T ; 23 184,30
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