Harry's GPS Suite Forum

Hi Harry,

I would like to run both a Kiwi3 plus a PACE Link (http://www.pace.car) on an OBD splitter/Y-cable with iOS. I use PACE mainly as Fahrtenbuch, while the Kiwi3 is for HLT. I have two questions:

1) Is it likely or not so likely to experience any interference between the two dongles (e.g. by disturbing each other on the Bluetooth wireless band)? I am sort of lazy to physically disconnect and connect each time...

2) Do you see a chance to have the PACE dongle supported? I mean, it is another German company that might be interested in selling more dongles through support for your GPS suite (i.e. HLT). Also there are currently very limited options for OBD via Bluetooth (because of camera via Wifi) under iOS. Maybe they will provide you with an API?

Thanks for considering,
TS

I doubt this will work, but maybe someone can report on his/her real life experience.

The PACE adapter will not get support by LapTimer. I have tried this with the Automatic adapter (similar to PACE). It has been complex to integrate and the performance is poor for track purpose. The reason is simple. These adapters run their own program (like logging or economics) consuming performance and bandwidth.

Harry

Harry wrote:I doubt this will work, but maybe someone can report on his/her real life experience.

...

Doubt because of overall Bluetooth bandwidth available? Or what would be the bottleneck in your opinion?

So far I thought these Y cables can handle one device at a time only (two plugged in but only one active).
But I may be wrong. I will probably order one to understand operation.

- Harry

Harry wrote:So far I thought these Y cables can handle one device at a time only (two plugged in but only one active).
But I may be wrong. I will probably order one to understand operation.

- Harry

I’ve run a naive test already and both OBD devices are definitely functional. The question is how stable the connection is under track day conditions. Is there a way to sort of “stress test” HLT wrt the OBD connection without being on the actual track?

I do understand that the reasoning why support for the PACE Link does not make sense. Still do you know more about the theoretical bandwidth of the total Bluetooth frequency band vs the portion used by one single device? So, if one device utilizes its own full bandwidth, how much is left for the remaining devices?

Thanks,
TS

I can't answer this precisely but know that the CAN bus will not be the limiting factor. When looking into ELM-based parameter requests, components on the path from smartphone / BT / adapter / OBD gateway / CAN bus / ECU and back sit and wait most of the time. You need to find someone with a *lot* of knowledge for communication on technical layer to answer this question in theory. I have ordered a cable and will report once I had a look into the effects.

- Harry

Hi again,

I got a Y cable and ran some tests connecting a Kiwi3 and a TONWON BTLE at the same time. I have experienced several issues and have never been able to get both working at the same time (using two smartphones). This is a slightly different scenario than yours (BTLE connections involved for both), but it looks at least like not all adapters work together.

Observations:

the Kiwi3 does not start advertising its GATTs (BTLE) while the TONWON BTLE is active already
the TONWON has problems with protocol negotiations while the Kiwi3 is active already

- Harry

Harry wrote:Hi again,

I got a Y cable and ran some tests connecting a Kiwi3 and a TONWON BTLE at the same time. I have experienced several issues and have never been able to get both working at the same time (using two smartphones). This is a slightly different scenario than yours (BTLE connections involved for both), but it looks at least like not all adapters work together.

Observations:

the Kiwi3 does not start advertising its GATTs (BTLE) while the TONWON BTLE is active already
the TONWON has problems with protocol negotiations while the Kiwi3 is active already

- Harry

Sounds quite a bit odd as this seems to be rather erratic behavior of both dongles. Maybe there is not enough juice (Amps) delivered to power both at the same time, which in turn makes them behave strange? Maybe bypassing and inducing a separate +12V line to the first OBD pin helps?

Do you have two Kiwis? Would be curious what happens if it is the same dongle twice.

Could you instruct me on how I can test in the car to create a log in HLT with the Kiwi3 while running PACE in the second port? I could then send the log to you.

Cheers,
TS

Why don‘t you try the Kiwi plus PACE yourself? Requirements are the same for public roads and tracks, so if the Kiwi shows stable operation on your way to work, it will be fine on track too.

Harry