Who wants an Arduino-based Aux Instrument Panel?

[Nautamaran]

The “driving” screens are coming together, and I’m working on the code for alarm set points this week.
So I needed to calibrate my “red” dip stick against the oil sump level reported by my van’s sensor.
The stick’s MIN..MAX range corresponds to 45..70 mm on the oil level sensor, but that’s only part of the story.

Once warm, with an oil temp of 180’F a “middle stick” oil level settles in around 30 mm while cruising, climbs to about 38mm at idle, and to about 55mm after shutdown. At 115’F the same sump shrinks by 5mm.

So the oil level alarm logic is compensated for RPM and temperature, since it is perfectly normal to see these variations, but if the adjusted level moves quickly or drops out, a major alarm (screen flashing) will trigger.

After watching my oil temperature all summer I’ve settled on 225’F as “normal” and 240..245’F as first stage (yellow) alarm, 245’F as a Red alarm (I’ve only reached 240 on extended hill climbs after I’ve saturated the cooling system).

These alarm points are stored in EEPROM, with an interface for adjusting them in the works.

-dave

Alarm points:
RPM . . V.Low . Low . . Normal . . High . V.High (hot)
0 . . <40 mm . 45 mm . .50.65. . 70mm . 75 mm
700 . (drop by 10 mm)
>1500 . (drop by 25 mm)

Stopped sump level vs sensor temp
Temp . Level
170’F . 55mm
135’F . 53mm
120’F . 50mm
110’F . 47mm

[Midwestdrifter]

Very thorough. I appreciate the RPM compensation.

[Nautamaran]

Originally Posted by Midwestdrifter

Very thorough. I appreciate the RPM compensation.

Thank you.
Nuisance alarms are the worst...

[JHGould5607]

Very cool stuff. Count me in. Where/how does the deposit work?

[sipma02]

I've got a lead on a 3D scanner and CNC mill, where I MIGHT be able to mill the negative shape of the driver's A-frame trim piece from foam. Then, we could use the CNC to cut a negative shape of foam out and lay fiberglass over that. Kinda like the image i attached. The Arduino instrument panel would be mounted in there. Still discussing with an engineering friend about feasibility. Any interest?

[Midwestdrifter]

I would be interested. I think 3D printing from a higher temp plastic would be easier/cheaper for a small production run. Black or a similar gray would be easy enough colors to source.

[turbodave]

sipma02:
Interested!
Dave

[koenb]

So talking something similar to this? Dave, can you tell us the demension of the enclosure? I wonder if we could retrofit a mount from edge tuner products. https://www.etrailer.com/Performance...CABEgJiBPD_BwE

[Nautamaran]

Originally Posted by koenb

Dave, can you tell us the dimensions of the enclosure?

The enclosure is a Hammond Mfg “1591C” in grey (1591CGY)

Nominal size (inches) is 4.7 x 2.6 x 1.4 deep

Grabbing a random one and my calipers...
The side faces are all slightly trapezoidal, tapering to the back face (to ease mold release)

Front (cover) face: 4.717” x 2.556”
Depth: 1.565” (1.410” to box/cover seam)
Back (bottom) face: 4.701” x 2.538”

The MicroSD card slot is cut in 1.235” from the outside end, 0.150” from the outside bottom face, and is 0.08” x 0.45” and aligns with the SD/clock card I have glued inside the enclosure.

The OBDII cable (1/4” diam) can enter through a side or the back face, as long as it remains clear of the SD board. A rear lower left entry is likely best, hiding the cable from the driver’s view and making it easier to push the box straight back into a support without cable interference.

Accessing the SD card in its current placement is a challenge if you add a mounting bezel... it can be rotated to come out on the left or right end, or it fits upright on the right edge (see photo), but that conflicts with the OFF switch, which can be moved to the left end if I remove the power socket from the Mega (which points at the end wall so I’m not using it, and it conflicts with the case’s lower left screw post anyway, which I’m trimming back with a router) There isn’t clearance above or below the screen for the data logging board.

There are ventilation holes (to be) drilled through the back along the upper and lower edges, clear of the support posts. I haven’t measured heat load, but it’s likely 15-20 watts, higher in direct sunlight.
Much of this comes off the buck, which is there to reduce the heat load on the Mega’s voltage regulator.

The voltage buck and my K-line board are stuck flat against the back of the Mega, and the screen pins in on top, which together with wiring uses most of the 1.3” inside box depth.

-dave

[koenb]

What if the off switch is removed from the enclosure and it gets remote mounted onto to one of the blank switch covers on the dash left of the steering wheel. Then the SD slot could be positioned where the switch is now and allow front access.