AFRuino?
 

I'm looking for something that will display the AFR on my LAF so I can see when i'm in lean burn mode and such.

Would this be possible with an arduino set up? DCB?

Thanks, :)

Probably, I don't know what a LAF is, but the arduino can do an analogRead of 0 to 5 volts pretty trivially, so it is well suited to a wideband. It could possibly be tuned to give a meaningful reading on a narrow band too, though that is pretty speculative. It can read the narrowband sensor turning on and off, just making sense of it is the hard part if you are not the computer controlling the mixture to begin with.

LAF = wideband.

Interesting. Perhaps after I get the MPGuino going I'll order a second set of stuff to make my AFRuino, :)

I think you just need another wire to one of the analog pins :)

Would it be that simple? It would be nice to have it on one gauge for thrift, but I'd want to see both at once...

In concept it is that simple. It would be good to double check how much current your LAF is handling with the car computer, how much it can handle total, and how much you will be adding with the guino pin. The chip is replaceable in comparison to the LAF.

There is of course some programming involved regardless. The quick and easy way is to hijack a screen with most of what you want on it and put the AFR in a corner. like on the instant/tank screen, display the AFR instead of the mph (I assume you have a speedometer)

Also you can map it to an actual AFR on the display but memory is a little tight at the moment, so if you just remember where stoic is and some target AFRs are in terms of 0 to 1023 then that'll get you there quicker, analogRead will return 0-1023. Multiply it by 1000 and pass it to format then to lcd.print() where we are currently printing instant.mph()

Or slap another guino together and go to town :) :
http://opengauge.org/diympggauge/dualguino1.JPG
http://opengauge.org/diympggauge/dualguino2.JPG