diy mpg gauge

[sonyhome]

Aahh... I still have to do this project and spend some time learning Java. i want to use Eclipse to do the R&D, but need time and must make a decision as to which graphic library to use (there's like 3).

Like ItsJstAGame, I've been lazy to find out where that dang Vss wire is, and how to wire the injector wire through the firewall.
Maybe I can get those signals directly from the ECU (?) inside the car.
I have plenty of crappy old laptops to throw at the problem.

Well, first, gotta fix my alternator and change the timing belt and do brakes.

ItsJstAGame:
You're not making much sense in that last post.

i'll just pitch in generalities, maybe it will answer what you ask:
If you have an A/C signal, the longer the duty cycle, the higher the voltage read. If you have a square signal duty 50% and max Vcc 50V, then the voltage you'll read is 25V (1/2 on, 1/2 off).

If your foot is on the gas pedal, you should not DFCO... Idle is 700~1000rpms, so you can use that as a base and play it by ear. Maybe go to what feels like very sluggish in 5th gear... Will be likely 1500rpm 2000rpm, and record when accelerating: no DFCO for sure.
If you like math and know the gear ratios then you can tell what RPMs you do at a given speed, say in 5th gear.

You should be injecting 4x per rotation on a 4 cylinder, right? Then you need to fudge in the injector size (cc/min), and it's trigger delay (it likely has a latency between the start for oozing gas from when the electric signal is on).

Lastly, your pictures have either high amounts of noise making them unusable, or you're soomed out and are seeing 100's of cycles.
Zoom in to 1 "noise" element, and compute it's frequency looking at the time line displayed by soundforge.
Your connection might be crappy: not shielded well enough and drudging noise from random stuff like the alternator, too inductive or capacitive, preventing the injector signal from reaching the sound card.

@#!$ I got to get my *** in gear and try this project... :\