★★★★George Graves★★★★ Project Blog for e30 Gizmos and Gadgets - 2025 UPDATE

[george graves]

QUESTIONS AND ANSWERS:

At least do a digital readout so you can have some degree of accuracy.

So - about the only "display" you can squeeze into a hazard switch is a LED bar graph. Perfect for a simple gauge - I don't need a numeric display - just something much smarter than a dummy light - and something less than a laptop riding co-polit.

I don't know how I could be more clear. Also - think about it for a second. When you are looking at a gauge such as your tach. You really are getting two pieces of information. One is what the current value is, and two, how *fast* or *slow* that value is changing over time. Digital displays are accurate, but unless they have some type of bar graph to go with them, they never really tell you how *fast* something is changing.

Keep in mind - this is just a small little project...

I think it's a great idea- you're not really concerned with the numbers usually as a driver for most engine parameters. You're really more concerned with whether something's inside parameters, getting close to being outside parameters, or outside of them.

EXACTLY!!! Plus the gauge is up fairly high - not down by the ash tray.

I want mine to be oil pressure. Or voltage, oil temperature or damn near anything that is actually useful!

Some possible gauges that could be installed inside of one of these:

Air/fuel ratio
Voltage
Oil Pressure
Oil Temp
Ammeter (how much current your battery/alt is delivering)
Boost
Nitrous Pressure (or pressure of anything)
Temperature (of about anything)
Exhaust gas temp
Parking distance
Air intake temp or degree of change before and after the inter-cooler.
ect, ect...

Sure, you would be a fool to try to "tune" with such a small gauge, but it would really provide a lot of feedback as to how a system is running. Like I said, sort of a "smart" idiot light.

+1 on the great idea! The VW crowd has something similar and they look great!

That guy is lucky that he mass produced the body of the gauge for cheap..

[TwoJ's]

Nice work. I was going to build a similar circuit, but my bar would not have been hidden so nicely.

[george graves]

Got a bit more done.

Once you have a working circuit and have tested it - it's time to start designing the PCB. Now, you remember the match stick games you would play as a kid? This is kinda like that but on crack. Your goal is to organize all the traces on the PCB so that the all parts connect to one another with out a single line over lapping - it's sick fun.

Here is the start - see all the "crossed" lines - that's no good.



Just when you move one component to fix something, it screws something else up. You do that till you are blue in the face. Some people "cheat" and send traces between the pins of components - I don't- if it's worth doing - it's worth doing it right.

After a few hours and lots of hair pulling, here is what it looks like. If it looks like I got "lucky" and everything just happen to fall into place - then I did my job.



A paper mock up - got it to just the right size to fit the "case" - no easy task



Kinda small hun? What ya think?

It still has room for improvement. So I'll do a mock up and see how everything fits. I can still tighten up alot of parts if need be.

Next up - build a one-off prototype.

[Erick]

some of us don't really care about the stereo - my music comes from a 7000rpm inline 6. ;)

Especially when an external wastegate fully opens past 4000rpms. :D

[Mike B.]

Very nice! For a some of the sensors it would be nice to have the LED's change from green to red as you reach a "danger" area.

[devonjordan]

Subscribed, not because I want one, just because its interesting...

[nando]

I'm interested actually - I'm not really into removing my vents for gauges, and I have the laptop if I want to do tuning. I do plan on doing something with my econometer, but that only takes care of one gauge out of two that I will need..

Especially when an external wastegate fully opens past 4000rpms. :D

eventually ;)

[xLibelle]

george, you can already count me in for one.
I support this kind of projects in full. :)

[Mtriple]

george, you can already count me in for one.
I support this kind of projects in full. :)

+1

[george graves]

+1 on the great idea! The VW crowd has something similar and they look great!

http://www.duostyling.com/frames.html

Anyone know what the printing method is to make those gauge faces? It looks like white is laid down first, the black with a transparent window - anyone know where I could find out more about that?

[UNHCLL]

Anyone know what the printing method is to make those gauge faces? It looks like white is laid down first, the black with a transparent window - anyone know where I could find out more about that?

You'll be hard pressed to find a printing company who can print the color white, at a reasonable price.
I'd wager that is a clear piece of very fine lexan, with white & black printing.
To have this done, you most often need to locate someone who can print on a "flatbed" printer.

HTH,
Chris

[Turf1600]

This is awesome. I want some for my 2002.

[xLibelle]

i dont care for the print under glass look.
I would rather it be like all the other prints in our cars, in raised form on the outside of the button surface.
Does vinyl come in different thicknesses? Find a thin one for laying down. It doesnt need a bunch of detail either IMO. Maybe just a "window" so you know the high/low limits.

George, how does the chip fit in the button cap? Can you post a picture of the two face to face to see the size or illuminate all bars behind the plastic... oh, is the rear defroster button just a section of yellow or is the entire button in color like the flashers? Another option of color if its whole.

[UNHCLL]

i dont care for the print under glass look.
I would rather it be like all the other prints in our cars, in raised form on the outside of the button surface.
Does vinyl come in different thicknesses? Find a thin one for laying down. It doesnt need a bunch of detail either IMO. Maybe just a "window" so you know the high/low limits.

Now you're getting into the realm of silk screening prints onto the material. Cost will go up even further, and clarity of the text/print will suffer.

-Chris

[george graves]

Yea, I hear you.

I'll post up some pics when I have more progress. The Hazard button is very RED, so the only LED's that are going to transmit any light is RED led's. The button will "filter out" green and yellow very effectively:( That and an LED produce almost a single color. Not a spectrum of light.



Not to mention it will be hard to find a brightness that is bright enough for day time, and not too bright for at night.

4 ideas:

- no printing at all (you'll just have to know what is what) LOWER COST
- a simple silk screen icon symbol BIT MORE COST
- build a "button" from scratch using heated plastic stretched over a mold, then trimmed. (lost of labor)
- tiny transparent sticker with white printing. (cheesy, almost rather have nothing)

What do you guys think?