Need guidance with custom pid

[JOHNBOY]

I have never had good results with logging EGTs. So I decided to scrap the old approach. I bought an AEM 30-5131 gage. It out puts a 5v signal that can be easily logged with external inputs on the V2. So far it is working great! My question is how do I write a custom pid to change the volts to Degrees F on my dash?
The scale is 0* = .5v and 1800* = 4.5v.

More info here. http://aemelectronics.com/files/instructions/30-5131%20Analog%20EGT%20SAE%20Gauge.pdf

Thanks

[5.7ute]

Should be simple since it is a linear output.
( EXT.ADn-0.5)*450

[darcy]

See page 5 of the manual that you've posted for the formulae.

For Temp in F* : {EXT.AD1} * 450 -225
For Temp in C* : {EXT.AD1} * 250 -143

[JOHNBOY]

Thanks guys!

It was right there in front of me. LOL

[joecar]

You should be able to modify your current pid (with the above formulae) so that the one pid produces both *C and *F.

[JOHNBOY]

I have not had a chance to alter the pid yet. Just referencing the voltage to the chart. Working great. To pulls with flawless EGT monitoring!
Very please with the AEM hardware so far.

[JOHNBOY]

OK not having much luck with creating the pid

I keep getting error
Error code: ERR_DUPLICATE/109

Duplicate *UNITS: F.



What am missing?


# ================================================== ============================
# File details
# ------------
#
# This section defines various details about the file format.

*FILE

#Parameter Value Description
#---------- ---------------- ---------------------------------------------------
VERSION 7.1.1 File version
DECSEP . Decimal separator used in this file



# ================================================== ============================
# Units
# -------------------
# See sae_generic.txt for more information on the *UNITS section

*UNITS

#Code System Abbr Description
#-------- ---------- -------- -------------------------------------------------------------
F Imperial °F "Degrees Fahrenheit"



# ================================================== ============================
# Add slot definitions here
# --------------------------------
# See sae_generic.txt for more information on "SLOT" formats
#
#Units Low High Fmt Expression
#------------ ------------- ------------- ---- --------------------------------------------------------------
*CLC-00-002
F 0 1800 .1 "{EXT.AD1} * 450 -225"


# ================================================== ============================
*PRN - Parameter Reference Numbers
# --------------------------------
# See sae_generic.txt for more information on the *PRN section
#
#Code PRN SLOT Units System Description
#------------------------- ---- ------------ ---------------- ---------------- ------------------------------------
------

CALC.AEM_EGT F066 CLC-00-002 °F Temperature "AEM EGT"

[JOHNBOY]

16962

[darcy]

Try putting the °F in inverted commas in both locations. ie "°F"

[joecar]

°F units already exist (as F), so delete your definition of it.

[joecar]

*CLC-00-002
F 0 1800 .1 "{EXT.AD1} * 450 - 225"
C 0 1000 .1 "{EXT.AD1} * 250 - 142.8"




CALC.AEM_EGT F066 CLC-00-002 "F,C" Temperature "AEM EGT"

[JOHNBOY]

OK It works great now. I screwed something up in the Calc_pid file. So I started fresh and it works as long as I leave out the defintions.
Thanks for all the help!

Any way here it is16969

[joecar]

Also, make sure there are 2 blank lines at the end of the calc_pids.txt file (i.e. after all the text).

[JOHNBOY]

Thanks for your help Joe!

[joecar]

no worries :cheers: