LM1 Calculated AFR PID

[VetPet]

I was looking at the Wide Band AFR 1 LM1 pid calculation that shows AFR = (EXT.AD1*10) and would like to know how you go about changing this calculation if you want to output the AFR from the 1 to 5 volt range? The above calculation covers a narrow range of input voltage and I would think it would be better to cover a 1 to 5V range instead in order to be more precise. There's no problem in programming the LM1 to output AFR based on the 1 to 5V scale. If anyone has done this I'd like to hear from you.

Thanks,

:cheers: :beer:

[Dirk Diggler]

You can define a new LM1 Pid in the calc_pids.txt file with a new name to use with your new voltages.

The calc pids file is located in MY Documents/EFILive/V7/User Configration

for an example on making calc check the
C:\Program Files\EFILive\V7\Configuration and look through the sae_generic.txt file for some examples

[SSpdDmon]

I made my changes directly to this file:

C:\Program Files\EFILive\V7\Configuration\sae_generic.txt

Open the text file and hit Ctrl+F to bring up the search window.
Type LM1 and find the equation "{EXT.AD1}*10" just above the highlighted text you just found.
Make your changes to this equation and the one for the EXT.AD2 just below.
Save the text file and close it.

That's it. You're done.

If you program the LM1 to read a little more in depth, I would set it the same as the LC1. That way, 7.35AFR=0V and 22.35AFR=5V. Then your equation would be "({EXT.AD1}*3)+7.35" in that case.

[Dirk Diggler]

If yu make changes to that file the next time you install the software from the installer it will get overwritten. It is best to put them in the calc_pids.txt file

[joecar]

Say you programmed your WB like this:
AFR10==0V and AFR20==5V

Then your WB AFR pid would look like either of these:
(20-10)/(5-0) * (V - 0) + 10
(20-10)/(5-0) * (V - 5) + 20

Both of these reduce to 2 * V + 10

[VetPet]

My thanks to all of you for your responses.
:cheers:

[dfe1]

I don't know about the set-up joecar posted (I've never tried those values), but in order to get my LM-1 logged data to match that in the unit display, I use the following--

# Innovate LM-1 WBO2
# ========================
*CLC-00-928
V 0.0 5.0 .1 "{EXT.AD1}"
AFR 10.0 20.0 .1 "({EXT.AD1}*1.9936)+ 9.9832"
*CLC-00-929
factor 0.0 2.0 .1 "{CALC.AFR_LM11.AFR}/{GM.AFR}
*CLC-00-930
V 0.0 5.0 .1 "{EXT.AD2}"
AFR 10.0 20.0 .1 "({EXT.AD2}*1.9936)+ 9.9832
*CLC-00-931
factor 0.0 2.0 .1 "{CALC.AFR_LM12.AFR}/{GM.AFR}

You can find more info about this at http://forum.efilive.com/showthread.php?t=1786&highlight=LM-1