diy mpg gauge

[EvilToothpaste]

Sounds like a good school project. I like the C++, and would be interested to see the final. I know more about that than I do Java, but still not much. I am most familiar with Python.

I made a quick schematic of the circuit I used and attached it below. I have a 6.8 zener only because that's what I had laying around. This particular circuit requires at least 12 volts on its input which means it can only be used on the injectors (my injectors make a 14.7V square wave with a 48V spike at the end of each pulse). You might be able to use it on Vss, actually, but only if it has at least 12v peak to peak. I used the same opposing diode circuit that Skewbe used for my Vss because I was too lazy to drag my o-scope out again to measure it after I had finally found the wire. Worked for him so I just went with it.

I can give you my sound file, but I don't have any gallon values for you because I haven't calibrated my stuff yet. I know that I topped out at 35mph, but that's all the info I have. hope it helps.

...except it's way too large. I'll have to email it to you. message me your email address and I'll send it tomorrow.