Thread: Anyone knows how can I convert the mileage to digital values?

Are you interfacing to the ECU?

That's what I heard ... need to interface the ECU... but I have no idea on the schematics and converting it to digital.... Is there a way u could recommend?

I'd start off by seeing if anyone else has done the same - have a good google.

If that fails, see if your car has a standard OBDII interface as that might greatly simplify things by defining standards etc.

If your car was an Impreza, either I or a friend could give you guidance, but as it isn't then I'm sort of stabbing in the dark.

FWIW, I'm going to interface to my ECU through a serial port connected to the car's OBDII connector using a Max232 chip to convert TTL to RS232 levels. The hardware is simple, it's the interrogation of the ECU that will be fun.

Or you could put a webcam pointing at your odometer, then OCR the resulting picture

Cheers,
Nick.

Do you have a GPS? This is how mine calculates distance travelled (although I didn't write the code, so don't ask me *how* it works!)

C!

Originally posted by chiark
Or you could put a webcam pointing at your odometer, then OCR the resulting picture

lol
i like that one

go find a vehicle speed sensor off a older ford or otehr fuel injected beastie and a analog to digtal converter and use a rs 232 converter to run it into a comm port
i have some info on making a stand alone digispeedo but i don't think it would be too hard to adapt to computer .. but what do i know i just think up stuff i can't code to save my life

Might want to check out Vetronix.com (I think that's the spelling). They provided and ODBII interface called the "CarPort" with usb or com port interface (can't remember which) that connected to the Clarion AutoPC (Windows CE Radio), which was based on standard i/o ....

I don't know that they sell the device anymore, but you can sometimes pick them up on eBay, and they may have information on their website ...

GTC

OOh.. be careful. Any commercial hardware for interfacing with the computer will be severely protected from doing any damage to the ECU. Just because the scanner port is there doesn't mean you should be randomly hooking up your carputer to it. A glitch to the wrong pin could kill the computer. We've lost enough ECUs just trying to use them correctly at my local tuner shop, it would really suck to have it happen on the street instead of a track or garage.

I can't think of the name but...

You get a magnet, and a matching weight to put somewhere on the driveshaft, (or for you FWD cars on one of the axle shafts) then a simple reed relay (or other more sensitive sensor) closes every revolution.

Add up the revolutions, multiply by the distance traveled by the tire in one revolution...you have distance...

Not pretty but that is how the tachometer in my truck works...and the speedo on my bicycle.