Modify logger Defs for Oil Pressure Sensor

Cam_Haug · **Joined:** Sun Aug 20, 2017 9:16 am **Posts:** 63

Hey all,

Trying to mod the logger defs to use a TGV for oil pressure, it is all working and wired and I can get it to work with BTSSM, however, I am having issues with the expression needed in romraider.

It is a 150psi sensor that outputs .5V at 0PSI and 4.5V at 150psi. does anyone know what I need in the expr= section?

Thanks in advance

Cam

dschultz · **Posted:** Mon Mar 04, 2019 9:17 pm

Try:

Code:

<conversion units="psi" expr="(x-25)/1.333333" format="0.00" gauge_min="0" gauge_max="200" gauge_step="25" />

Cam_Haug · **Joined:** Sun Aug 20, 2017 9:16 am **Posts:** 63

Awesome thanks, that works great

now how did you get to that?

dschultz · **Posted:** Tue Mar 05, 2019 5:46 pm

The default conversion for TGV voltage is x/50.
x is in the range 0 to 255 (for a byte).
Each x value is therefore worth (1/50), or 0.02 VDC
If 0 psi = 0.5VDC, then x at 0 psi = 0.5/0.02, or 25.
That gives the x-25 part of the expr.

150 psi is = 4.5 VDC, so x at 150 psi = 4.5/0.02, or 225
The x range for 0 - 150 psi is 25 to 225.
This means that each x value is = (225-25)/150, or 1.3333333333333333333333333333333333...
Therefore expr = (x-25)/1.333333

nitros · **Joined:** Sat Sep 17, 2011 11:20 pm **Posts:** 51

If anyone is interested in this.

https://www.bmotorsports.com/shop/produ ... ts_id/4236
https://www.bmotorsports.com/shop/produ ... ts_id/2220

https://www.bmotorsports.com/shop/produ ... ts_id/4080
OR
https://www.amazon.com/AUTEX-Pressure-T ... B00NIK98O8

BCush83 · **Posted:** Fri Oct 02, 2020 3:32 pm

Im assuming this wont work if I deleted TGV and run AVCS (v7 207)..do I have another similar option to log oil pressure?

Cam_Haug · **Joined:** Sun Aug 20, 2017 9:16 am **Posts:** 63

You would need a spare 0-5v input doesnt matter what it is from.

Cam

05Pzev · **Joined:** Sun Jan 03, 2016 10:05 am **Posts:** 217

Sorry to dig this one up but does it matter if I use P39 or P40? Are they effectively the same?

P39 is the "Tumble Valve Position Sensor Right" sensor and P40 is the left one?

It seems like to me that (on my car) the driver side connector controls the motor, and the passenger side is a just sensor. The motor from the right hand side controls the left hand side through physical linkage. I would think the left side would be better, but for some reason when I open up romraider logger, I only get the right hand sensor sensor listed.

Cam_Haug · **Joined:** Sun Aug 20, 2017 9:16 am **Posts:** 63

They are the same, on my 07 Liberty/Legacy they are both 5 pin plugs for the tgvs.
There is a black 2 pin on the left hand side as well. It is not that one.

Cam

05Pzev · **Joined:** Sun Jan 03, 2016 10:05 am **Posts:** 217

Interestingly the plug on my right hand side is a 2 wire, and the left side is a 3 wire. I think the 2 wire is a motor and the other is a sensor maybe?

I think I need the 3 wire one right?

05Pzev · **Joined:** Sun Jan 03, 2016 10:05 am **Posts:** 217

Why would I only see P39 but not P40 in romraider logger?

It looks like I would need to log P40 because it is a 3 wire connector, while P39 is a 2 wire. I'll check my definitions but I think they are relatively new.

05Pzev · **Joined:** Sun Jan 03, 2016 10:05 am **Posts:** 217

dschultz wrote:

The default conversion for TGV voltage is x/50.
x is in the range 0 to 255 (for a byte).
Each x value is therefore worth (1/50), or 0.02 VDC
If 0 psi = 0.5VDC, then x at 0 psi = 0.5/0.02, or 25.
That gives the x-25 part of the expr.

150 psi is = 4.5 VDC, so x at 150 psi = 4.5/0.02, or 225
The x range for 0 - 150 psi is 25 to 225.
This means that each x value is = (225-25)/150, or 1.3333333333333333333333333333333333...
Therefore expr = (x-25)/1.333333

If I am using the same sensor, but on a "front o2 sensor" circuit, which uses x/200 then is this correct?

1/200 = .005 vdc
x at 0 psi = 0.5/.005 or 100 so use "x-100"

x at 150 psi = 4.5/.005 or 900
range for 0-150 psi is 100 - 900 so (900-100)/ 150 = 5.333333

Code:

<conversion units="psi" expr="(x-100/5.333333333333333)" format="0.00" gauge_min="0" gauge_max="200" gauge_step="25" />

Does that look right?

05Pzev · **Joined:** Sun Jan 03, 2016 10:05 am **Posts:** 217

05Pzev wrote:

Interestingly the plug on my right hand side is a 2 wire, and the left side is a 3 wire. I think the 2 wire is a motor and the other is a sensor maybe?

I think I need the 3 wire one right?

Ok I get it now, I am slow. It is mis-identified in RomRaider logger or perhaps simply backwards on my weirdo California emission scar . It says "Tumble Valve Position Sensor Right" but it is really on the left hand side of the car. The left hand is the sensor, and the right hand is the motor on my car. P39 is physically located on the left hand side of the car but is described as right. So this input will work perfectly.,

I finally figured it out by hooking the old TGV sensor up to it, with logger laptop , and a screwdriver to move the TGV sensor physical input , watched logger to see if P39 was the one I was looking at.

So when in doubt, validate what you are looking at.

05Pzev · **Joined:** Sun Jan 03, 2016 10:05 am **Posts:** 217

Does anyone know if I can log 0-5v do rear o2 sensor or does that need to be 0-1v only?

gnabo · **Joined:** Mon Mar 13, 2017 11:10 pm **Posts:** 82

Rear o2 sensor can read 0-5V.
I use it with wideband o2 sensor.

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