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Logging Rate / Channels

Posted: Thu May 14, 2015 12:31 pm
by mechanicalchris
Hi All,

I did a fairly decent length log recently, I noticed that only RPM and Vehicle Speed log at an acceptable rate (probably too quick for what the use is) but other channels such as ignition, engine load, throttle position, MAP, IAT and other basic but important parameters log too slow for it to be of any use. Some channels such as ignition timing actually stop recording after about 500 samples which completely baffles me.

I understand with a CAN system it works of a priority manner, rather than a constant stream of data, so if RPM has a high priority, it will always "jump the que" to ask to be logged.

I guess - is there a way of making the logging of channels more efficient or is this vehicle dependant? I've only tried this on one car so perhaps it's an issue with this particular vehicle.

Other people's experience with this would be great.

Cheers,

Re: Logging Rate / Channels

Posted: Fri May 15, 2015 9:31 pm
by stanley
This has nothing to do with CAN priority. Nevertheless CAN bus is not the only protocol the logger supports. Please take look at the sketch and you will know how the PIDs are logged at different rate. You can of course change it or only log PIDs you want.

Re: Logging Rate / Channels

Posted: Sat May 16, 2015 6:31 am
by FastZyx
I've resolved using a loop in logOBDData() to have all pids each time. In the latest sketch Stanley has modified logOBDData() in logOBDData(pid), so the loop must be in the loop() function