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Re: OBD data frequent freeze

Posted: Wed Mar 29, 2017 3:31 pm
by steved0x
Harry wrote:O.k., that’s the long story with all the background, here are the steps for the workaround:

In LapTimer ‣ Administration ‣ Settings ‣ Expert Settings ‣ OBD Tweaks / Exclude PIDs, enter

Code: Select all

	0900092009400902
...

- Harald
Hi Harry,

Can you share the string that excludes all PIDs except for RPM and Throttle Position?

I have been having trouble with slow OBDII update from my 2000 Boxster, but I have recently changed the video recording in HLT on my Android phone from HD to one of the lower resolutions and I want to see if that takes some of the load off the phone's CPU and frees it up to process the updates from the OBDLink Bluetooth device, and I also want to try excluding everything except RPM and TPS. And then if that is slow, I want to exclude everything but TPS.

Thank you,

Steve

Re: OBD data frequent freeze

Posted: Wed Mar 29, 2017 3:52 pm
by Harry
steved0x wrote: Hi Harry,

Can you share the string that excludes all PIDs except for RPM and Throttle Position?

I have been having trouble with slow OBDII update from my 2000 Boxster, but I have recently changed the video recording in HLT on my Android phone from HD to one of the lower resolutions and I want to see if that takes some of the load off the phone's CPU and frees it up to process the updates from the OBDLink Bluetooth device, and I also want to try excluding everything except RPM and TPS. And then if that is slow, I want to exclude everything but TPS.

Thank you,

Steve
We are off topic, for further questions, please open a new thread, or use one of the existing optimization threads (we had several discussions to improve update rates by excluding PIDs here on the forum).

The lever available to achieve higher update rates by tweaking PIDs is extremely "short". LapTimer request only a minimal set of PIDs at a high rate. PIDs requested at low rates have almost no impact on the rate. PIDs included in high update rate group are RPM, MAP, TPS, wheel-speed. MAP is not relevant for the Boxster (not available), so what remains is RPM and TPS and wheel-speed. RPM can't be removed and considered mandatory throughout the code. Removing it will bring you to 0 Hz. So what remains to optimize is wheel speed - it can be replaced by GPS speed in calculations. Wheel speed is 010D. For further information on PIDs, please check https://en.wikipedia.org/wiki/OBD-II_PIDs

The problem is, car buses were slow back in 2000. 2 Hz (8 to 9 PIDs/s) is the max you can expect. Lower rates are possible.

- Harry

Re: OBD data frequent freeze

Posted: Wed Mar 29, 2017 9:30 pm
by steved0x
Great, thank you Harry!