Designing Dash Gauges

[Beesme]

Where would you install sensor on rear diff ? Would you just strap thermocouple on pumpkin ? I lost rearend a few yrs ago .that would have saved a lot of cash and almost burned coach to the ground .. Thank God I had big fire extinguisher....

[Jim Eh.]

The sending unit goes into one of the threaded plug holes. There should be one below the full level plug so that the sensor is fully submersed in diff oil.

[akroyaleagle]

I'm using a program to draw out the electrical schematics for our bus.  I completed the easy page first and that was the exterior lights.  Next is the Instruments on the dash, like the oil pressure and water temp, etc.  So what do people have in their dash's?  What would you want and don't have, what do you have and don't want?  I'm going to have a gauge and a color changing LED for warning lights, such as low oil pressure, low voltage, etc.  So here's what I am thinking;

Gauge          -                warning light comes on when....

Charging volts gauge from engine - Warning at 11volts (is that about right?)
If the altenator is working properly, it should read over 14V (12v system)
Water temp gauge - what is too high? 200?
Optimum operating temp for best combustion in diesels is 195. The light should come on about 205, the alarmstat should shut the engine down about 210.
Trans temp gauge - what is too high?
Anything over 300 degrees is too hot.
Oil pressure gauge - What is too low?
Mine reads 65+ at operating speed. 45-50 at idle when warm. (Most don't read that high.)
Boost Gauge
You probably will be about 7 lbs at normal speeds around 2000rpm. Something over 20 when working the engine hard in a climb.
Speedometer
80mph speedometer is best. It and the tach should be the same size and in the center of the dash.
House Batt volt gauge - 11 volts again?
As someone pointed out, 11 volts is a dead battery. It normally should read over 12V. (12.7 is fully charged)
Inverter  - What do I need to monitor here?
You monitor the inverter if you monitor AC voltage.
GenSet Temp gauge - 200? it will probably be a diesel
190 is better.
Oil Temp gauge - What temp to high?
If you observe water temps, oil temp will take care of itself. I don't monitor it. If I did, I would figure out what it is normally and be concerned if it rose much.
Fuel pressure Gauge - What's too low?
If mine fell to 45 lbs I would change the filter. (Hasn't ever happened) It's about 65psi.
Air pressure 1 - 60 PSI
Air pressure 2 - 60 PSI
I would probably be concerned if I saw air pressure below 90 during normal operation.
Front air suspension pressure - Not sure what PSI yet, will have to weigh it, I want these just to be able to see it
Rear Left suspension pressure
Rear Right suspension pressure
I don't know much about air suspension, but why wouldn't they be the same?

Anything else? Exhaust temp?
See the other discussion topic about that.
I might install and inter-cooler but not sure yet.

It's a 4107 with a 77' DD8v71T with an auto, assuming allison

[lvmci]

hi daddy of ten, I would search for LED Bulbs in my instruments, instead of regular bulbs. no heat, no changing of bulbs. but I think I would get a two big screen tablets, load it with gauge software, put one on either side of the steering column, and arrange the software gauges any which way suited me best,including your gps, heck you could even insert your rear and side camera monitors on the screen,and zoom it out when your backing up! lvmci...
p.s. Phone could blue tooth thru it too!

[TedCalvert]

Moosemanusa, I like your idea! I've thought of doing the same myself, someday. 
Tell us more.

Ted

[expressbus]

Eric,
About a year ago I changed out my original factory gauges using the same panel layout. One big reason for changing them out was night visibility. The gauge background was black the indication levels were white. Now White on Black sounds like a good plan. This may have worked IF the bulbs were brighter. In the daytime it was less of a problem to read the gauges. I found a source for gauges where the background during the day was White with Black indicators and at night the background changed to a light blue (my choice, other colors were available). Now that the gauge face colors were sorted out the other original feature I did not like is the factory gauges were not full sweep.

I found that a full sweep of the indicator and positioning the gauge so that the normal indication is vertical (toward the top of the panel) made it easier to glance at the gauges and assess if any problems were emerging. The only gauge I did not change, because a new gauge was not available compatible with the new faces/background, was the Twin Pyrometer gauge in the dead center of the dash. So now I simply make repeated sweeps from lower left around the top of the panel to the lower right and finish at the one gauge that remains troublesome to read at night, the pyrometer.

[TomC]

Early on, I bought 5 different colored 50ft 3 wire extension cords, bundled them together, and ran them from the engine compartment to the driver's compartment. Now have 15 wires to add whatever. Have used 2 for tachometer, 2 for cruise control. Good Luck, TomC

[moosemanusa]

Sensors send Ohms, a sensor is just a range of "x" ohm to "x" ohm, the gauge is calibrated at the factory to translate send "x" ohms into a numerical numbers on your steam gauge (sorry aviation term there)

So using a tool like this:

http://www.mouser.com/ProductDetail/Advantech/ADAM-4150-AE/?qs=HSwFsqQPTVMtvXppLy%2Frtg%3D%3D&kpid=1209998227&gclid=Cj0KEQiAgMKmBRDMjo_F9OfUubABEiQAp8Ky15RkIpIE1Unyt5HJlWVjS8c9jMlH7lhxmrOUaZhavCMaApzX8P8HAQ

Then linking that to say a GPIO on a Raspberry PI to read those ohms from a pre-setup GPIO port/pin.

use a simply Python and PHP script to read that current value and translate into a graphical format.

I just did this project using relays, i did it in a day and found all the examples code online (i'm not a code person) but it was common logic to edit it how I wanted it..

Raspberry PI is $35 computer, they just released a new quad core version that will run Windows 10 (free)!

[moosemanusa]

Here is a complete page to how someone did it in the past!

https://learn.adafruit.com/downloads/pdf/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing.pdf

[luvrbus]

How do convert for it to read analog gauges ? the electronic engines are a snap Martin @ SilverLeaf has that covered

[moosemanusa]

how do the analogues read from the sensors?

I was under the impression it was still ohms to a guage. (since the 50's for sure)

or is it more old school than that?

[sledhead]

not in the dash but just to the right of it is my prosine invert er remote  control + the tri-metric 2025a to see how the eng. and  house batteries are doing . 

  <a href="http://s1280.photobucket.com/user/crane66/media/82e7e93e-0a3b-4666-a6c8-753894ecbcde_zpsbe0486ac.jpg.html" target="_blank"><img src="http://i1280.photobucket.com/albums/a484/crane66/82e7e93e-0a3b-4666-a6c8-753894ecbcde_zpsbe0486ac.jpg" border="0" alt=" photo 82e7e93e-0a3b-4666-a6c8-753894ecbcde_zpsbe0486ac.jpg"/></a> 

dave

[moosemanusa]

love it! semi glass cockpit there!

The Raspberry Pi's can also be made into a $100 portable camera system (think backup camera with a magnetic mount) that could be moved anywhere, simple wifi connection from your phone to view it. you can power it with a cell phone battery charger.

[daddyoften]

WOW, Thank you all for the great ideas and reply's.  I'm quite busy with work right now and will read more detail when I have time.  But thank you!

[RickBrown]

Go digital! The ability to resolve engine temperature to a degree will enable you to manage your hill climbs and the ability to resolve your oil pressure to a couple of psi will tell you when your oil level is getting low.
-RickBrown in Reno, NV