OBD-II owners, how fast is your updates?

cproaudio · 09-21-2003, 08:27 PM

I know there are a lot of people on this forum who have obd-ii setup. For those who has the obd-ii setup would you please post a pic of your digital dash and what hardware and software are you using and how fast is your update speed.

bh76 · 09-22-2003, 12:31 PM

No digital dash here, just a character display. I'd take some pics, but I don't have a digital camera.

On my setup I have it display fuel sys status, engine load%, temperature, fuel trim, RPM, speed and timing. It updates about twice a second. To compensate for the slow update speed it helps to setup a priority system. For example, RPM needs to be updated more often than temperature.

For hardware, I'm using an ELMScan VPW board.

carabuser · 09-22-2003, 12:49 PM

Quote: Originally Posted by bh76

No digital dash here, just a character display. I'd take some pics, but I don't have a digital camera.

On my setup I have it display fuel sys status, engine load%, temperature, fuel trim, RPM, speed and timing. It updates about twice a second. To compensate for the slow update speed it helps to setup a priority system. For example, RPM needs to be updated more often than temperature.

For hardware, I'm using an ELMScan VPW board.

so again, why wouldnt this be appropriate to calculate lets say 1/4 mile time? maybe not exact, but if its +- .5 sec, works for me

(http://www.mp3car.com/vbulletin/showthread.php?t=16937)

DocBru · 09-22-2003, 01:29 PM

Well, if you only poll for a single value it should be even faster, shouldn't it?
Is there any spec that helps to clarify the maximum possible values? Is this vendor dependent?

I'd say 10 samples per second would be quite good for live dashboards / calculations.

Regards
Bruno

bh76 · 09-22-2003, 09:58 PM

Quote:

so again, why wouldnt this be appropriate to calculate lets say 1/4 mile time? maybe not exact, but if its +- .5 sec, works for me

If +- .5 sec is accurate enough, go for it. Just keep polling the speed as fast as the hardware interface will take it. In the other thread someone mentioned using interpolation. That'll help too.

One remaining issue: distance
I'm not aware of any way to have the OBD-II interface read the odometer. The next best thing would involve keeping track of the time, as well as the speed, then calculate a distance estimate based on that.

Quote:

Is there any spec that helps to clarify the maximum possible values? Is this vendor dependent?

Here's a link a thread on the Scantool.net forum. They explain it better than I can.
http://www.scantool.net/forum/index....ay;threadid=25