Building a simple Fuel/Air mixture Meter?

Somewhere in the long past, I remember seeing instructions for building a simple LED display that would attach to the O2 Sensor and give a simplistic idea of where the air/fuel mixture level was at. I've since done a little searching, and can't find the same simple little system. I see lots of complicated systems, and ones for sale that are already put together.
In addition, I think this particular design was put together by a fellow bimmer owner, and perhaps was even set up specifically for an E30? I could be way off on that last bit :-)

Anyone remember seeing what I'm talking about, or better yet, have a link? :-)

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Earendil
Somewhere in the long past, I remember seeing instructions for building a simple LED display that would attach to the O2 Sensor and give a simplistic idea of where the air/fuel mixture level was at. I've since done a little searching, and can't find the same simple little system. I see lots of complicated systems, and ones for sale that are already put together.
In addition, I think this particular design was put together by a fellow bimmer owner, and perhaps was even set up specifically for an E30? I could be way off on that last bit :-)

Anyone remember seeing what I'm talking about, or better yet, have a link? :-)

Would a three LED display do the trick...lean ... lambda ... rich?
This shouldn't be too difficult to do.

I don't remember seeing such here though.

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Archeo-peteriX
Would a three LED display do the trick...lean ... lambda ... rich?
This shouldn't be too difficult to do.

I don't remember seeing such here though.

The one I'm thinking of had something like 12-16 LEDs, with 3 or 4 RED on either end to indicate extreme conditions.
I've looked around the standard BMW How-To articles at places like Pelican, and can't find it. This leads me to believe it was at least a topic of discussion at some point on BENN. But perhaps I really did come across it someplace further out in the mists of the internet.

As the wiring in my car becomes more and more fragile, and finding annoying little "once in a while" bugs that are hard to trace. A live system to help monitor parts of my car might be useful. Plus, I'm now taking an Electronics class, and this would make a nice side project.
By the end of the semester, if I haven't found it, I'll probably just design my own and post it here for you guys :-)



Edited 1 time(s). Last edit at 02/23/2009 01:40AM by daniel.

Sounds like a sensitive voltmeter whose output is slaved to an led array, no? Couldn't you just bypass the led stuff and get a voltmeter that is accurate to the hundreth place?

alan

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Earendil

Quote
Archeo-peteriX

Would a three LED display do the trick...lean ... lambda ... rich?
This shouldn't be too difficult to do.

I don't remember seeing such here though.

The one I'm thinking of had something like 12-16 LEDs, with 3 or 4 RED on either end to indicate extreme conditions.
I've looked around the standard BMW How-To articles at places like Pelican, and can't find it. This leads me to believe it was at least a topic of discussion at some point on BENN. But perhaps I really did come across it someplace further out in the mists of the internet.

As the wiring in my car becomes more and more fragile, and finding annoying little "once in a while" bugs that are hard to trace. A live system to help monitor parts of my car might be useful. Plus, I'm now taking an Electronics class, and this would make a nice side project.
By the end of the semester, if I haven't found it, I'll probably just design my own and post it here for you guys :-)[/quote]

We did discuss making a display that would show the condition of all the relays. This would be an invaluable aid in troubleshooting non start situations and other hard to isolate problems.

A 12 - 16 LED O2 read out that looks like a graphics equalizer output would be neat.

Found it!
It wasn't on Pelican's main list of articles.

[www.pelicanparts.com]

The article describes a 20 LED system for monitoring the air/fuel mixture, adjusted for the none linear functionality of the O2 sensor.

If I get this projected started, I'll make sure to make a more detailed how-to than the one that Pelican has posted. I should be able to take some pictures as well.



Edited 1 time(s). Last edit at 02/22/2009 05:28PM by Earendil.

Quote
Earendil
Found it!
It wasn't on Pelican's main list of articles.

[www.pelicanparts.com]

The article describes a 20 LED system for monitoring the air/fuel mixture, adjusted for the none linear functionality of the O2 sensor.

If I get this projected started, I'll make sure to make a more detailed how-to than the one that Pelican has posted. I should be able to take some pictures as well.

Looks like a fun project

check this out

[r3vlimited.com]

it is a long thread, but the guy is in the process of making the meter for all sorts of applications, so read through and see what you think. there is a video in there at some point also.