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.

diy mpg gauge
 

hi,
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

Welcome to the site. As I recall that wasn't a leaf blower, it was "Ghetto Ram-air" Lots of people here have Scangauges. I even have one on my 4wd pickup truck.

-Jay

Software
 

Can anyone tell me where to get software to work for my ELM327 so I can read constant and instant MPG? miles per gallong.

I am having trouble, I have a 1994 Honda Civic EX. it has a Map Enhancer, I dont know if this makes a diff or not.

Need help

Thanks, Will

There's many free programs for the ELM327. Here's the names of a few, google for them to get their websites:

OBD-II ScanMaster
scantool.net
obd2crazy / wOBD
EasyOBDII
OBDII Logger

thanks, however I need something to display MPG for my ELM327 1.2a

i haven't tried it on another car, only thing I can think of is mine is a MAP sensor, so what program would do the trick as these don't display.

Oh, now I think I understand what you were saying about MAP in the other thread. In that case, I don't know what you can do. :(

Yup it sucks. I dont understand how it can't tell with a MAP sensor. as thousands of people must wanna know this.

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.

Anyone have a hint?

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!