[SOLVED] OBD WLAN dropping. Using w/Jailbroken ...

[ben]

Doing a fresh wipe of my iPhone didn't help. I figured it was worth a shot.

OBDKEY doesn't work well at all no matter if I try it on my iPad or iPhone. Update rate is through the roof (10-13hz) but it just drops too much.

PLX Kiwi is supremely stable on the iPad. No drops at all. Update rate seems to be 6-7hz which is fine.

[Harry]

And the same PLX Kiwi has drops with your iPhone? Then it is clearly a hardware issue, and / or a compatibility problem...

- Harry

[ben]

I'll be doing more testing when I'm out of town and away from any other wifi noise. I am comfortable using the iPad for all my logging, so I'm happy I have something that works well.

People on the PLX forums reported similar problems - 30 seconds of data with several seconds of drops. They released a firmware update but it is no longer available on their site and it was apparently only for older models (pre-2010).

[ben]

So after making a trip through the middle of nowhere to a town that is almost in the middle of nowhere, I was able to confirm a few things.

Using my lap timer that came with my car (Sport Chrono option), I was able to see that I was losing OBDII data at almost exactly 60 second intervals -- on either the iPhone or iPad . Every 60 seconds, it drops for about 10 seconds, then reconnects. The iPhone seems to have more frequent disconnects so for me I'm still sticking with the iPad.

I have no idea how I once got the PLX Kiwi to get data without drops in the first place.

I've read about wifi issues in general with iPhones/iPads. They are bizarre and apparently even changing the brightness level of the phone can "fix" a problem - that's an official Apple fix too, I'm not kidding. That could serve to explain why it's been so difficult to try and track down why one time I was able to get a great consistent stream of OBDII/GPS data and I haven't had any luck since.

[KrisS]

I have exactly the same issues with OBDLINK Wifi (5-10 sec drops of connection every 40 to 50 seconds).

- changing brightnes and turning the automatic brightness off
- turning off and on wifi
- forgeting the network defined
- resetting network values

did not work. Any clues ?

[ben]

I've tried it all Kriss, no luck.

[KrisS]

I did further tests.

- Connected to OBDLINK with Hyperterminal and disable all power saving features in the OBDLINK itself (Voltage change, Voltage for sleep, wake up, etc).
- Updated ios version to iOs5 (final one not the developer beta)
- tested the OBDLINK with other car (Skoda Octavia 1.8 TFSI and Focus RS MKII) and still the connection is lost, it reconects and so on....

The OBD Update rate is high 8,3 HZ and that is fine assuming the OBD is connected
HW version is 4.7
Firmware - latest available 2.2.2

As for adding the connection to iphone before starting apps I tried adding the WiFi connection to OBD (id: ScanTool.net) either with DHCP or manual address and still the WiFi is not stable.

The WiFi works just fine when logging with SCANXL on Notebook so it seems that it is iPhone HW or iOS realted issue. Any solutions for this ? Maybe some timeouts to be changed on OBDLINK side ?

Harry- any hints ?

[Harry]

Hi,

Unfortunately not. I talked to the OBDLink people - they are not aware of an issue with OBDLink and iPhones... Only point I took with me is they use the same wifi setup (chip) like the Kiwi people. I understand iOS5 does not solve the problem, we will see if we get changes with the iPhone4GS to further track this down.

- Harry

[KrisS]

Based on discussion of OBDLINK forum they are aware. Their position (quite logical) is they do not support issues with the 3RD part applications/systems. On the other hand on their site and Marketing materials it is said it works with few iPhone apps including your Lap Timer. I would say that does not works fully as communication breaks every 40 to 60 seconds. Not looking to bash here anybody , rather looking for solution.

Their regular route is : check if it works with PC - works - then it is not HW isue on the side of the OBDLINK. Then it is considered as iPhone HW, IOS or iPhoine app issue.

Is there any way to log the network communication between the iPhone and OBDLINK ?
Maybe that is a kind of timeout or different communication speed of OBD interface and WiFi on iPhone ?
Maybe iphone looks for the new networks all the time and breaks communication for a moment in defined intervals and it is visible in situations where constant data flow is required ?

K

[ben]

I did some testing like you Kriss and used the obdkey software on a laptop to connect to the obdkey and it didn't drop the connection at all. It is consistently monitoring a lot of inputs and I'd setup one to stream more continuously (RPM). No drops at all.

I also tried something else - I connected my iPad to an ad-hoc network I created by my laptop and ran ping tests to the iPad's IP. No packet loss at all even pinging for 10 minutes.

Something seems off between the iPhone/iPad and the ad-hoc network created by the obd wifi device. Perhaps it is an issue with 802.11b vs 802.11g or the channel used. Maybe it has to do with other more advanced wifi settings (beacon interval, fragmentation threshold, etc) though I'm not sure if those apply to ad-hoc networks.

I'm trying to get the obdkey guys to tell me how to change the wireless settings of the obdkey.

I wouldn't mind trying to run Harry's Laptimer in the iPhone Simulator (I have the latest xcode and iphone simulator) to further ensure the problem is truly with the ipad/iphone wifi