Good point, I'm sure we could change the code to work in this way possibly. Right now though the code just looks at each injection event. That is the 'pips' we see on the sound graph, it estimates that each pip corresponds to a certain amount of injected fuel and during a longer duty cycle would read as multiple 'pips' depending on how long is lasted. It samples at 44Khz (that's 44,000 times/ sec) and if the value is above a certain threshold it calls that a 'pip' and says fuel was injected.
For VSS is does the same thing, if it samples and sees a value below a certain treshold (like bottom of sine wave), then it knows one rev of the driveshaft (or whatever) has gone by and calculates the appropriate distance that that counts for (based on calibration and setup).
So at any given time we have a pretty fair estimate of injection events/length of injection time and number of VSS 'pulses' and can displaying anything we want based on this data.
I just joined this site...and in browsing around, I came across this thread.
Many of us (most?) who drive / want a MPG gauge but don't "speak the language" of electronics ... Jimmy Clark was a sheep rancher ... have a good way out of this dilemma : Buy a ScanGauge! It's a little pricy, but seems sound and bulletproof.
Go to <www.scanguage.com> for details. I've just gotten one, and am tickled with it! -Ted
P.S. While the "edit" button is still hot, let me just say - I went to the "gallery of pics" thread, just to check it out. When I saw the pic of the "Leaf blower", I went ROTFLMAO
Arg! Trying to do this on my 1990 Honda Accord (F22A1 engine, 5 speed), and I can't for the life of me find the VSS. It doesn't match any factory service manual I can find, and the diagram on the last page of this thread doesn't match the box under my passenger seat at all... totally different kind of connector.
Hello, everyone! Although I have just registered, I have been wanting to do my own realization of this kind of gauge for over a year now. And now I've finally started doing it.
The thing is - I don't really want to connect it to my car before it is at least partly ready.. So, I would really appreciate it if anyone could provide me with a stereo sound recording of VSS and injector signals. It would be even better if someone could also provide some values, like total distance covered and fuel spent for the duration of this recording, so I could do some testing with some with "real-life" calibrated values.. but if such data is not available, I would be happy with just a sound file
Thank you in advance!