Powerlogger, Scanmaster-G, ALDLDroid, and Pressure sensor

[Turbo6inKY]

So, I added an oil pressure sensor and tied it into my Powerlogger, and wanted it to register correctly in ALDLDroid. The default for the analog inputs just spits out the voltage coming from the sensor.

I bounced some emails back and forth with Sebastian (the guy that wrote ALDLDroid) and this is how I got it to work.

In the SCMG_BT_ALDL_001.adx file you get from Bob, there are blocks for the analog inputs. Here's what the block for Analog Input 4 looks like:

<ADXVALUE id="Analog4" idhash="0x9840CBD8" title="Analog Input 4">
    <packetoffset>0x0E</packetoffset>
    <sizeinbits>16</sizeinbits>
    <range low="0.000000" high="255.000000" />
    <alarms low="0.000000" high="255.000000" />
    <digcount>2</digcount>
    <outputtype>3</outputtype>
    <unittype>32</unittype>
    <MATH equation="X*5/65535">
      <VAR varID="X" type="native" />
    </MATH>
  </ADXVALUE>

The parts we care about are the title in the first line, and the MATH equation. The Title changes the display name for whatever gauge you assign on the dashboard, and also changes the name of the field in your data logs.

The Equation part is where you tell the software how to take the value coming from the sensor and turn it into something that relates to what you care about. In this case, (X*5/65535) is how the software takes the sensor value and turns it into voltage (0-5v).

The 100psi pressure sensor I got for my car reads 0psi at 0.5v, and 100psi at 4.5v. So, the conversion is ((X*5/65535)-0.5)*25 = psi.

So, the completed block is:

  <ADXVALUE id="Analog4" idhash="0x9840CBD8" title="Oil Pressure">
    <packetoffset>0x0E</packetoffset>
    <sizeinbits>16</sizeinbits>
    <range low="0.000000" high="255.000000" />
    <alarms low="0.000000" high="255.000000" />
    <digcount>2</digcount>
    <outputtype>3</outputtype>
    <unittype>32</unittype>
    <MATH equation="((X*5/65535)-0.5)*25">
      <VAR varID="X" type="native" />
    </MATH>
  </ADXVALUE>

So, change this block in the ADX file and save to a new name, then upload it on your tablet and tell ALDLDroid to use it, and viola, you'll have a pressure reading in PSI instead of volts!

 

[Evaddave 87gn]

sub'd

 

[TurboBob]

you can also edit the adx file with tunerproRT. but great job. I will be adding the additional sensor definitions to the Scanmaster G and will expand on the adx file at the same time.

Sebastian has been very helpful to me also.

Bob

 

[Turbo6inKY]

you can also edit the adx file with tunerproRT. but great job. I will be adding the additional sensor definitions to the Scanmaster G and will expand on the adx file at the same time.

Sebastian has been very helpful to me also.

Bob

That would be awesome! Being able to see the oil pressure on the Scanmaster G would be fantastic. Right now I'm having to pull the logs off the phone and run them through MegaLogViewer to actually see the results (or have PLC running).

 

[Evaddave 87gn]

That would be awesome! Being able to see the oil pressure on the Scanmaster G would be fantastic. Right now I'm having to pull the logs off the phone and run them through MegaLogViewer to actually see the results (or have PLC running).

Just curious why you are logging oil pressure? Are you just trending the data to look for wear?

Dave

 

[Turbo6inKY]

Just curious why you are logging oil pressure? Are you just trending the data to look for wear?

Dave

Initially, I wanted to see if the car was starving for oil when pulling 1+ lateral G on autocross and road courses. It's not. The stock oil pan and baffle are perfectly adequate. Which means you don't need a fancy oil pan on this engine.

Then, I switched to 5w20 weight oil. I built the engine on the tight side, so the lighter oil means a tad more power and a lot less heat in the engine when I'm running it at WOT for twenty seconds down a 2200' front straight, but I needed to be sure that it maintains pressure with the lighter oil. And it does.

And now that I have a lot of good baseline data, I can review it periodically and yes - I'll be able to see the pressures start to decline as/if the bearings wear. Combine that data with periodic oil analysis, and I'll be able to tell way ahead of time when to pull the motor and refresh it again.

 

[Evaddave 87gn]

Wow, very cool. Thought about autocross. That might be in the books for the second revision of this car in a few YEARS....LOL

 

[Sixxpack2go]

Hate to re-hash an older post... But this is AWESOME!! I would like to set it up for FP also- I like to monitor EVERYTHING if I can. Makes diagnostics a snap(and I always am chasing gremlins of some sort). Thank you Turbo6inKY