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

[Mtriple]

gg, I replied to your post over on the tech.

[Jamil]

George I hope you have a very important high paying job because you're smarter than most of the very important highly payed people I work with.

I'd also be very interested in an oil-temp gauge. Good luck and thanks for the light dimmer thinga-magigee.

[Erick]

Hey George,

Is there any chance to make the LEDs color coded (Red/Green/Amber) based on where they sit? (low/high voltage)

[franco90]

OK - I now have two gauges completed.

One is a voltmeter, the other a Narrow band AFR. Both are "plug and play"

Voltmeter:
- Measures very accurately from 10.5 volts to 15 volts in 0.5 volt increments.
- Only will require two wires to hook up - power and ground.

LED 1 10.5 volts
LED 2 11 volts
LED 3 11.5 volts
LED 4 12 volts
LED 5 12.5 volts
LED 6 13 volts
LED 7 13.5 volts
LED 8 14 volts
LED 9 14.5 volts
LED 10 15 volts


AFR(air-to-fuel ratio) gauge:
- Gives you a ball park measurement on how your car is running. Will warn you about a dangerous lean or rich condition.
- requires Power and ground
- no need for a second O2 sensor, you can tap your existing sensor. (if you want to know why this is possible - it is because my unit has a huge impedance rating - in the +20 Mega-Ohm range
- AWFUL for tuning a turbo - so if that is what you are doing right now - please don't buy one.

LED 1 REALLY LEAN
LED 2 REALLY LEAN
LED 3 REALLY LEAN
LED 4 LEAN
LED 5 GOOD RANGE
LED 6 GOOD RANGE
LED 7 RICH
LED 8 REALLY RICH
LED 9 REALLY RICH
LED 10 REALLY RICH

(If you know narrow band AFR gauges - you'll understand why I listed the values as I did)

The only last one I'll will make with this design is a WIDEBAND air-fuel ratio display. It will require that you already have a wideband o2 and an LC-1 or the like. Other than that it will plug into the second output of the unit and only require power and ground.

The oil pressure, boost and others will require a slightly smarter design. So that's in the works as we speak - plus a few other surprises!

Please post up if you are interested in either the volt meter, or narrow band AFR gauge - I'll include that in my next parts order...

how much for the volt meter do you have a picture of it ....

[NC325iC]

im definitely interested in both the afr (wideband) and the voltmeter

[george graves]

George I hope you have a very important high paying job...

LOL - thanks...

Hey George,

Is there any chance to make the LEDs color coded (Red/Green/Amber) based on where they sit? (low/high voltage)

I'll play around with that. The thing is that the tint to the button acts as a light filter - it being so RED - it will filter out greens, blues, ect.

I MIGHT be able to get away with red-yellow-orange set up.

how much for the volt meter do you have a picture of it ....

I'm on the fence regarding pricing. It's more or less a custom circuit, with lots of labor to boot.

[franco90]

George
please Pm me your Price

[george graves]

GOOD NEWS!

New parts coming in tomorrow (finally!)

I sent an order in two weeks ago for all the parts for the OBC temp sensor replacements that seems to be a hit with everyone.

http://www.r3vlimited.com/board/showthread.php?t=110651

And I added to the order all sorts of fun parts to make this and a few other project work. I'll post up pics of the all the goodies when they come in...I'll let you see what $200 in parts for testing looks like.

[george graves]

Parts are in!

I'm almost giddy with excitement as one of the parts that is needed had a 3 month lead time. Meaning - I've been waiting for 3 months on this ONE part to get my grubby little hand on it. That's not fair....

I have OBC temp sensors to ship out on monday(tuesday), and then a new web design to wrap up that I'm excited about - after that, I'll have some updates.

[george graves]

Here is what $200 in electronic components looks like. Kinda sad hun? You'd think you get more for your money. Most bags have only 4-5 parts in them.




Here is the finished voltmeter board. (ohh clean fingernails FTW) The design is all finished and ready for production.



And the finished product minus the button/case.



Some of you requested different colored LED's. Here is why it won't work with the button.


Light just won't get through. I even tried yellow and a orange-ish red. The orangish red worked but the color difference isn't enough to be of much use.



The redness of the button just blocks/filters out all colors that is not on it's wavelength. Oh well. I really think the red matches the interior better anyways.

This is a little testing rig I built a while back for testing my interior light delay w/ auto dimming units. I test each one twice. Once it's been ruffly assembled and once when it is ready for shipping. Inside this case is a full mock up of a cars interior light circuit. On the sides are two interior lights. The switches let me simulate a door opening or the ignition being switch on or off. I'll have to make something like this for these gauges as well.



Well that is all for today.

I need to order one of these guys. It's a variable bench top power supply. I've been getting away with using a 12v 30amp power supply, but I really need something that is super accurate and controllable. I really need it if I am going to be making gauges and need to calibrate them accurately and quickly.



Next up is some teaser shots of what other things I've been working on - I'll try and get that up as soon as next week.


...

[Mtriple]

:pimp:

[devonjordan]

I would eat these up....

[alexw]

Count me in on a AFR at least. I'm not too sure i know why a voltage reader would be useful? maybe someone could explain?

[george graves]

If the gauge shows:

Low on start THEN good on running(or after getting a jump) = Healthy alternator, bad (or going bad) battery.

Low on start, AND stays low - Bad alternator.

The voltage your system provides changes ALL sorts of things. In modern fuel systems for example, they go so far as to compensate injector timing dependent on voltage.

It's also good for seeing what affect your lights/stereo/cold have on the battery.

[winfred]

useful info if something craps out like the battery or alternator, may keep you from getting stranded if you saw it wasn't charging and investigated the problem before the battery runs down

Count me in on a AFR at least. I'm not too sure i know why a voltage reader would be useful? maybe someone could explain?