Using the AnalogX preset in CAN Mapping

[PS14]

i've added two 1600psi brake press sensors( and a 0-5v fuel level sender) to my AnalogX, aND can mapped it using the preset. should i leave the min max at 0/5000 mv? or do i set them to 0-1600? i have data, but the gauges flutter around 500psi with no fluid in the system (havent bleed it out yet) so i would expect to see 0psi. or maybe i need to adjust the formula? Dave

heres a snapshot of the sniffer results:
[935444.0]: 251.0, 5.0, 6.0, 0.0, 227.0, 1.0, 9.0, 2.0,
[935444.0]: 57.0, 6.0, 6.0, 0.0, 37.0, 2.0, 24.0, 2.0,
[935444.0]: 63.0, 6.0, 8.0, 0.0, 46.0, 2.0, 231.0, 1.0,
[935444.0]: 248.0, 5.0, 3.0, 0.0, 221.0, 1.0, 233.0, 1.0,
[935444.0]: 249.0, 5.0, 4.0, 0.0, 222.0, 1.0, 242.0, 1.0,
[935444.0]: 9.0, 6.0, 12.0, 0.0, 9.0, 2.0, 28.0, 2.0,
[935444.0]: 23.0, 6.0, 17.0, 0.0, 18.0, 2.0, 38.0, 2.0,
[935444.0]: 5.0, 6.0, 9.0, 0.0, 9.0, 2.0, 19.0, 2.0,
[935444.0]: 9.0, 6.0, 9.0, 0.0, 6.0, 2.0, 20.0, 2.0,
[935444.0]: 254.0, 5.0, 8.0, 0.0, 239.0, 1.0, 13.0, 2.0,
[935444.0]: 26.0, 6.0, 11.0, 0.0, 17.0, 2.0, 39.0, 2.0,
[935444.0]: 60.0, 6.0, 9.0, 0.0, 29.0, 2.0, 50.0, 2.0,

MK2 1.12.1

[brentp]

Hi,

Configuring the CAN mapping formula is the key for calibrating the sensor. What do you have as the formula?

[PS14]

I did not change anything other than the units (0-1600) and channel name after choosing the AnalogX preset. so the formula is 1.0 / 1.0 + 0. my list of channels looks like this;

AnalogX_1
FuelLvl
FRBRK
RRBRK

does the dump look like three sensors are providing data? I don't need to use virtual channels, do I?

[PS14]

I noticed in the AIM integration guide it mentions most AIM 5v press sensors use a multiplier of 0.01, so I'm assuming this should be changed. I'm going to bleed it out this weekend so I have press to work with, then i'll know for sure if the values displayed on the gauge are correct.

Couple of things I noticed last night:
1. I got a line in my dump with a diff CANID, weird. looked like this,
[935444.0]: 60.0, 6.0, 9.0, 0.0, 29.0, 2.0, 50.0, 2.0,
[935424.0]: 60.0, 6.0, 9.0, 0.0, 29.0, 2.0, 50.0, 2.0,
[935444.0]: 60.0, 6.0, 9.0, 0.0, 29.0, 2.0, 50.0, 2.0,

2. on my win10 running 1.12.1, I cannot see the unit conversion section in the "add can channel mapping" dialog box. tab or right arrows wont choose it and I cant grab it with the mouse. just me or an issue?

3. I'm guessing it doesn't matter what range 5v press sensor you attach (100psi or 1600psi) AnalogX adapts to the range? since the formula wouldn't change?

[brentp]

Hi,

1) AnalogX outputs different CAN messages. To see the different message types, see the CAN API here: https://wiki.autosportlabs.com/AnalogX

2) On the CAN channel editor, try clicking / dragging the blue header on that popup dialog. That should get you to the units conversion tab.

3) So long as it's a linear output sensor, you can use the formula to scale the 0-5v to a real world value.

For example, 0.5v = 0PSI, 4.5v = 150 PSI

formula would be:

RAW * 37.5 - 18.75

Hope this helps!

[PS14]

unfortunately, that didn't work. brake gauges read 215650 and fuel level reads 9285. so here is what i got and what i did. i am mapping 3 channels thru AnaologX. a linear 0-5v fuel level gauge and a pair of 1600 psi brake pressure transducers. i took your formula example and thought these formulas would work:
Fuel level - raw*25/1.0+(-12.5) (to show 0-100% on gauge)
Brake - raw*400/1.0+(-200) (to show 0-1600psi)

i also tried your formula but obviously somethings not right.

[PS14]

If I understand the sample broadcast is in mV, so would these formulas work? assuming the RAW at 0.5v is 500, and RAW at 4.5v is 4500?

for the 0-100 gauge: RAW * 1.0 / 40 + (-12.50)
for the 0-1600 gauge: RAW * 16 / 40 + (-200)

[PS14]

followup: these formulas appear to work correctly.

[brentp]

Sorry for the late reply; glad you figured it out!