OBDLink stuck/lockup issue

I have been struggling with the occasional lockup problem of the OBDLink device. To be fair the device is probably not designed for continuous high speed operation as we do in PriiDash. I am copying info from this original thread:
https://www.scantool.net/forum/index.php?topic=5027.90

The symptom of the lockup issue is that the device stops responding to commands and keeps sending the same message to the PC. At this point the only cure is to disconnect both the USB and the OBD cables. Then reconnect them.

There is another, much less frequent issue, but I nevertheless noted it in the post below, that the device would reset itself. The reset undoes some of the initialization steps of PriiDash. In this case one has to click the Go/Stop button twice to stop and re-initialize the device.

 

Record of lockup events

My car is almost exclusively used for daily commute, about 40 ~ 60 minutes each way. Here is a (partial) list of the lockup events that I have experienced:

Locked up again this morning 2011-07-27.

Update: happened again this morning 2011-07-28.

Update: and again the same day afternoon 2011-07-28.

Update: Updated the FTDI drivers to the most recent version yesterday 2011-08-02. It went well for two trips yesterday but this morning it got stuck again 2011-08-03.

Today 2011-08-04 OBDLink decided to reset itself again during a trip. Very frustrating.

Update: got stuck again this morning 2011-08-05. And again this afternoon 2011-08-05.

And again this morning 2011-08-08.

Yet again this afternoon 2011-08-10. This is after removing one of the multi-frame queries from the program.

And again the next afternoon 2011-08-11.

Yet again afternoon 2011-08-16.

2011-08-17 afternoon.
2011-08-22 afternoon.
2011-08-24 afternoon.
2011-08-30 morning and afternoon.
2011-08-31 afternoon.


Just had two lockup in a row this afternoon 2011-09-15. I have changed the FTDI driver parameters packet size from default 4096 to 2048 and latency from default 16 ms to 2 ms since 2011-09-01 afternoon and haven't had a lockup event until today. I am changing to 1024 and 2 ms. Crossing my fingers ...

Update:
This afternoon 2011-09-20 OBDLink decided to reset itself again. At least in this case no cable disconnect/reconnect is needed.
This morning 2011-09-21 OBDLink locked up again.

2011-09-22 lockup again (512, 1ms)
2011-09-27 lockup again (1024, 1ms)
2011-09-30 lockup again (2048, 1ms) At this point I have exhausted the parameter space. Still no solution.
2011-10-03 lock up again.
2011-10-04 lock up again.
2011-10-06 lock up again. (1024, 1 ms) I will let it lock up three times before moving to the next setting to see if at least there is some combination of parameters that at least lock up less frequently.
2011-10-06 lock up 2nd time.
2011-10-07 lock up again. 3 strikes in 3 consecutive trips. This is the most frequent seen so far.
2011-10-11 lock up after 3 good trips. (512, 1 ms)
2011-10-13 lock up after 3 good trips (and a 4th very short one).
2011-10-14 lock up after 1 good trip. This ends the 512, 1ms combo.
2011-10-17 lock up after a few good trips. (256, 1 ms)
2011-10-24 lock up 2X in the same trip after quite a few good trips.
2011-10-27 lock up after 4 good trips.
2011-10-27 lock up again at a new setting. (384, 1 ms)
2011-11-01 lock up again after a few good trips.
2011-11-02 lock up.
2011-11-03 lock up.
2011-11-04 lock up. (192, 1ms)
2011-11-09 lock up in the morning after 4 good trips in previous days.
2011-11-09 lock up again in the afternoon.
2011-11-29 lock up when the weather got warmer after a period of cold weather and no lock ups. I start to suspect temperature again.
2011-12-02 lock up.
2011-12-05 lock up.
2011-12-05 lock up in another trip soon after changing to (256, 1ms).
2011-12-08 lock up.
2011-12-14 lock up.
2011-12-15 OBDLink resets itself.
2011-12-20 lock up.

2012-01-03 lock up.
2012-01-04 lock up.
2012-01-05 lock up.
2012-01-06 lock up. Hmmm... It's getting more frequent now. Don't know why.
2012-01-07 lock up.
2012-01-10 lock up.
2012-01-11 two lockups in one trip.

 

What has been tried to solve the issue

Fellow PriusChatter ccdisce kindly spent a lot of time debugging and modifying the device without much luck. I am truly grateful for his effort and generosity.

I have tried

• Swapping the device and cables
• Removing ScanGauge and Y cable
• Changing serial port timing settings

without any luck either.

The only clue I have is that the lockup seems to happen less frequently if I remove some multi-frame request(s).

 

The new firmware fixed the most frequent lockup issue but there are still less frequent issues such as the SX self-reset or keeps saying "OK" or "STOPPED".

 

Thanks for helping with this issue. For others who didn't know ccdisce has been spending a lot of time helping with this issue from the hardware side. I hope this "STOPPED" issue can be fixed by firmware like the lockup did.

 

I am testing beta firmware for OBDLink SX at 2M baud rate and so far it looks like they may have finally fixed the various issues I was experiencing. Give me a week or two to be sure of the result, but so far it looks very promising (no problem yet).

 

OBDLink guys fixed a few bugs in the firmware (including the lockup issue) and they should come up with an official release soon.