Problem: Using Bluetooth OBDII AND Bluetooth XGPS on Droid

[vincenzo]

Hey Harry -

Not sure if you want bugs reported elsewhere, but I was at Laguna Seca this past week and of course using Harrys Lap Timer for Android on my Moto X. (Thanks as always for a great product!) I noticed a couple of bugs, one major the others very minor.

#1
While driving with both the a bluetooth OBDII and a bluetooth XGPS connected to Harry's, my car's dashboard gauges randomly went to zero a bunch of times (both speedo and tachometer.) This was alarming, but the car was still functioning normally. I strongly suspect this has something to do with the OBDII because when I've used the app Torque to reset ECU error codes in the past, I've also noticed the gauges dropping to zero for a few seconds. (Normally, I'm parked while doing this, so it was never very concerning.) The car is a 2005 Lotus Elise and I'm using one of the generic ELM 327 OBDII bluetooth devices.

Because of the gauge issue, I only ran one session with both the OBD and XGPS connected. I can probably send you the data output if that's helpful to diagnose.

#2
When looking at data for a single lap, clicking the "breadcrumb" in the top left should take me back to the lap list, but instead takes me to the home screen. Very minor but thought you might want to know. The Android "back button" (near the home button) works as expected though so once I figured that out it was no big deal.

#3
You can't select multiple laps in the lap list. I forgot to set my car at the beginning so then I wanted to update about 50 laps all with the same vehicle profile but there wasn't a way to do it.

[Harry]

#1 I'd be alerted here and this is *not* a LapTimer issue: in case you get that effect with the OBD plugged in only, I'd assume there is an issue with the OBD gateway / the dongle. Although there are some write operations possible with OBD dongles (mainly reset errors), LapTimer is a read only application and will never do anything that changes car operation. This is one of the reasons I recommend genuine OBD dongles by the way, I really do not want to plug one of these Chinese copies without any certification into my car.
#2 Works as designed, this would be a duplication of the return key otherwise. It seems conventions for the return item are not consistent in Android, but throughout LapTimer, it will bring you back to the home / guide view.
#3 There is no multi-select option in LapTimer. But it is a smart app: just select any of the laps and change the car. In case the lap is part of a session or track day, LapTimer will ask you whether you want to switch cars for the whole session, the whole track day, or the lap only. Multi-select plus changing one of a lot of attributes is a cumbersome using pattern as does not guide you while doing individual changes (when changing the car, it will change the whole multi-selection, when recalculating acceleration it will do what?) in a huge dialog like Lap Details.

- Harry

[vincenzo]

Hey Harry -

Thanks for the detail, I figured it probably is an issue with my OBD reader. I'm going to look into an alternative and will check the lotus forums to see what people recommend. But it sounds like there shouldn't be any issues using two bluetooth devices at the same time with Harrys Lap Timer, right?

On #2, no problem. Once I figured it out I just used the return key.

For #3 though, it never did ask me after I changed it for one lap. I went in and did them all manually. Would have loved it to work as you described!

[Harry]

#3: You are right, I tested it using the iOS version but see I have it disabled in the current Android version (it is implemented, but there has been an issue with dialog handling). Will recheck that for v18.

- Harry

[vincenzo]

Hey Harry -

Just wanted to follow up on #1 because I was speaking to some other Lotus drivers at the track today and they said they too had this problem with various apps and dongles. It might be specific to the Lotus but they mentioned something that the dashboard is on the CAN-BUS, rather than the OBD2 BUS and that this might have something to do with it.

I'm looking into it further because I'm worried that even if I buy a certified OBD2 dongle that I might still have this problem.

Thread here on Lotus Talk if you're interested at all:
http://www.lotustalk.com/forums/f3/plug ... er-119283/

[Harry]

Hi,

There is no such thing like an OBD bus,.. Instead, an OBD dongle will send requests to whatever bus is available (CAN bus in you case) and receive its information from it. So if you disconnect the CAN pin, you will not receive information any more.

Given the bandwidth a CAN bus provides, an OBD dongle requesting information should not be able to disturb the system like it in your case. In case the OBD dongle, or dashboard, or CAN implementations are crappy, there might be a mutual dependency like described.

I would not take this easy. While OBD is not a mission critical component in you car, the CAN bus is. The dropping dashboard speed is an indicator the bus operation gets handicapped!

See my first reply and either try another dongle or don't use OBD currently.

Harry

[vincenzo]

Hi Harry -

Just wanted to follow up on this. I got the OBDLink MX and tried it the other day at a trackday. During the first session, I still at one point had the gauges drop to zero, but then it never did it again all day and everything was fine. So I still am not 100% sure what is caused it but hopefully it's no longer an issue.

Thanks again for the great product!