Analog to Digital Dash conversion (STE/ICE - help)

[JAG]

Looking to create a arduino setup that reads analog inputs such as:
Oil Pressure
Coolant Temp
Fuel Level
etc
Displaying them on a TFT LCD screen

Instead of putting in some VDO sending units, I was thinking of using the STE/ICE port, since all signal wires are going to it.

I looked through the TM-9-6625-2301-10 and I cannot find any wiring diagram / pin output. Was hoping to not have to do a deep dive with the multimeter.

Came across this thread where they set up and used the Diagnostic Kit - which is converting the analog signal to digital. I don't see why i couldn't install a mini computer to do the same thing.

MSD-ICE Kit Diagnostics

People sell these disks, that’s what it depends on. Benjamin People may sell them, but that's theft. These are copyrighted materials.

www.steelsoldiers.com

Any thoughts on how to find the pin outputs and thoughts on a digital gauges display through an LCD dashboard ?

 

[Agelai]

I’d be very interested to see how you do this.
so your plan is to keep the original harness and send it to a unit that converts it to a digital read out?
Do you plan on using like a tablet to display the data?

 

[JAG]

I’d be very interested to see how you do this.
so your plan is to keep the original harness and send it to a unit that converts it to a digital read out?
Do you plan on using like a tablet to display the data?

That’s the thought process,yes. I was hoping to hear from some others, in the group, that may have more electrical knowledge. But from what I understand you have to use sending units that are less than 5v to use in conjunction with the Arduino computer. I would presume that the 5v sending units would take place of the existing. However, I was indeed hoping that the existing wiring would be beneficial to “tap” into and run that wire to the computer. I have yet to determine that.
sending unit aside, the Arduino would be used to convert voltage or pressure, for the oil pressure gauge, to a value that is represented on a digital display (lcd screen).
ie temp gauge at 180 degrees equals 3.2v. That would then be converted to the display. Same for rpms, battery voltage, etc etc.
it’s assuming the sending unit goes from 0v to 5v and those voltages outputs converted into a reading on the display (a gauge).
The programming code is one thing. Getting the sending units is another.
I thought MAYBE there was a way to tap into the STE/ICE port sense all of those signals are going there anyways. But I can’t find a pin out diagram for it anywhere.
the diagnostic machine that you connect to it is simply a mini computer as well, converting the analog signal to a digital one, running tests that you’re wanting to check.

 

[Mogman]

All the sending units are based on resistance and would be a real challenge to convert to 0-5V this would take some time with a variable pressure source.
I have never actually measured the voltage on say the oil pressure sending unit but would assume that it can go above 5V which would be bad news for the Arduino inputs.
The best suggestion I would have would be to add additional 0-5V dedicated sending units, this would surly give you much more accurate readings, battery voltage can be monitored by using a simple voltage dividing resistor network.
Unfortunately you probably will not get much technical information about the military test sets, that kind of information is not very common.
The pin-out for the STE is in the vehicle schematics


Actually it looks like very little of what you want to monitor goes to the STE, no oil pressure or temp!
It looks like it is mostly for starter current and charging voltage

 

[Mogman]

For the tach, depending on whether you have a turbo truck or not, just about all but the turbo truck simply use a reed switch attached to the top of the oil pump drive,
it switches 2 times per revolution and as it is being driven at 1/2 crank speed so the output is 1 "pulse" per crank revolution, that would be simple enough to use as unless you have a factory tach it is only used as a diag connection, I used this for an input to the TCM for my 6L80 conversion.

 

[JAG]

All the sending units are based on resistance and would be a real challenge to convert to 0-5V this would take some time with a variable pressure source.
I have never actually measured the voltage on say the oil pressure sending unit but would assume that it can go above 5V which would be bad news for the Arduino inputs.
The best suggestion I would have would be to add additional 0-5V dedicated sending units, this would surly give you much more accurate readings, battery voltage can be monitored by using a simple voltage dividing resistor network.
Unfortunately you probably will not get much technical information about the military test sets, that kind of information is not very common.
The pin-out for the STE is in the vehicle schematics
View attachment 859609
View attachment 859610
Actually it looks like very little of what you want to monitor goes to the STE, no oil pressure or temp!
It looks like it is mostly for starter current and charging voltage

Those diagrams are unfortunate- I thought for sure there would be more information going to the STE port. And two, still trying to understand what pin goes to what is still unclear. I really appreciate you locating those. What TM did you find it in?

You're probably correct about the factory signal wires being higher voltage. But when it comes to putting in another sending unit, Do you put it 'in place of' the current sending units with the 5v ones? I attached some pics of what I think would be needed.

I am not sure it would be too difficult to get the proper readings. If you could tap into the factory sending unit/signal wire and see what the multimeter says in relation to the current gauge.
i.e. 30psi oil pressure would equal 1.5 volts.

The real conundrum is probably going to be getting the programming code correct so that the gauge actually moves based on the input's voltage.

 

[JAG]

For the tach, depending on whether you have a turbo truck or not, just about all but the turbo truck simply use a reed switch attached to the top of the oil pump drive,
it switches 2 times per revolution and as it is being driven at 1/2 crank speed so the output is 1 "pulse" per crank revolution, that would be simple enough to use as unless you have a factory tach it is only used as a diag connection, I used this for an input to the TCM for my 6L80 conversion.

That's a really great point. Currently I have the 6.2 with the 4l80e. I wired up a digital tach to the generator, and used a Dakota Digital Signal Interface (SGI-100BT) to convert the signal.

I'm really wanting to try and do this. The hardest part , for me, is understanding how to get the info to the Arduino. i.e. sending units/transducers etc.

 

[Mogman]

You can simply add additional sending unit along with the stock ones, the oil and temp sending units are pipe thread, just add a T.
Seems like allot of work just to avoid looking at the stock gauges not much really going on anyway, you are going to have to find transducers that have the range and signal you need,, but best of luck to you!!

 

[JAG]

You can simply add additional sending unit along with the stock ones, the oil and temp sending units are pipe thread, just add a T.
Seems like allot of work just to avoid looking at the stock gauges not much really going on anyway, you are going to have to find transducers that have the range and signal you need,, but best of luck to you!!

It may be an exercise in futility however it’s more of a practical learning experience for me and perhaps a little cool factor to go along with it. Thanks for the tip on the sending units. That’s the info I was after.

 

[JAG]

You can simply add additional sending unit along with the stock ones, the oil and temp sending units are pipe thread, just add a T.
Seems like allot of work just to avoid looking at the stock gauges not much really going on anyway, you are going to have to find transducers that have the range and signal you need,, but best of luck to you!!

Sorry for my ignorance. You got a picture you can share of this “T” junction? I’m not able to find it.

 

[Mogman]

OK. I have a hard time believing anyone does not know what a pipe T looks like but here you go.
Mogman OUT!!