OBDII bluetooth / wifi speeds?

[Mgaz]

So I want to buy an OBDII adapter to send engine info to an android device.

But on a lot of videos I've seen, there seems to be lag / delay / slowness in the response of the virtual dials in relation to the real dials. Such as rpm's etc.

Is this sluggishness the result of the android device ? The cars own ECU or the OBDII adapter plugged into the socket?

I've noticed some OBDII adapters claim to be faster than others. So am I right in thinking that these cheap £4 adapters are the problem?

Basically what I want to do is mount an inclosed android device in the car and use the torque app or something similar to display real time info . But it needs to be 100% real time for an authentic effect.

I'm guessing the problem comes from the speed of the OBDII Bluetooth device at reading the ECU info and transmitting it fast enough ?

Has anybody bought one that is fast enough to display in real time?

I'm also wondering if I buy a wifi OBDII reader instead of a bluetooth one, will it be a lot faster?

This would also free up the Bluetooth for audio streaming .

Anybody experience of a wifi OBDII adapter? Is it much faster?

[fandango151]

By nature they will never be real time.

It is a challenge response protocol. Device says give me speed, adapter translates, car responds saying yep I'm doing 50 for example. Device then asks again and so on. Add more data points and it will slow down. Being digital this sampling is the only way and the cars own system do this fast enough not to be noticed/split it along various systems etc.

Most cheap Obd adapters use clones of elm327 chips... Have a quick Google. Results can vary massively with clones - some don't even work. Wifi/Bluetooth will make no difference as Bluetooth and WiFi are both faster than the slow interface of the car.

Personally I don't like the idea of constantly interrogating the ecu especially as some vehicles (not the rover as far as I know) shut systems down when being interrogated as it consumes processing power to answer the requests from the adapters - but that is just me.

Not much help for you but hopefully that sparks some thoughts.

[Mgaz]

Thanks !
The part about the requests having an impact on processing power is interesting. Would that mean there would be an impact on the ecu's ability to respond to sensor inputs and keep things running like clockwork? So to speak?

Or would it have no noticeable effect on the running and performance of the engine?

I hear you on the elm clones. It seems very hard to know what is and isn't a good buy? But googling doesn't seem to give any clear advice other than pointing to the very most expensive adapters like blue driver or obdlink LX.

Maybe there isn't a decent reasonably priced unit?

[suzublu]

PM me your address & I'll send an ELM 327 I have spare

[fandango151]

Originally Posted by Mgaz

Thanks !
The part about the requests having an impact on processing power is interesting. Would that mean there would be an impact on the ecu's ability to respond to sensor inputs and keep things running like clockwork? So to speak?

Or would it have no noticeable effect on the running and performance of the engine?

I hear you on the elm clones. It seems very hard to know what is and isn't a good buy? But googling doesn't seem to give any clear advice other than pointing to the very most expensive adapters like blue driver or obdlink LX.

Maybe there isn't a decent reasonably priced unit?

How long is a piece of string? From my basic knowledge it would depend on how much the cars ecu has to handle vs. it's resources as well as how it has been programmed to handle such eventualities.

I've never experienced it and the functionality is there for diagnostic purposes. I've read of issues with some ford's chevvies and the odd Japanese cars things like misfires and check engine lights but you never know. I know for sure if I probe the abs or instrument pack on my chrysler (so not Obd but deeper tools) traction control dies until restart and the dash bongs (why every vehicle action results in a bong on an American car is beyond me).

Lots of people do have displays etc so may just be me being paranoid, I mean some android head units have it built in. Might be trial and error for an adapter that works

[marinabrian]

If you are having a slow day, take a read HERE this is the protocol the ECM uses in all communication of the diagnostic/live data variety

Brian

[stevestrat]

Originally Posted by marinabrian

If you are having a slow day, take a read HERE this is the protocol the ECM uses in all communication of the diagnostic/live data variety

Brian

[Mgaz]

Originally Posted by marinabrian

If you are having a slow day, take a read HERE this is the protocol the ECM uses in all communication of the diagnostic/live data variety

Brian

erm.. thanks! THAT is a lot of information. I don't suppose there is a small bite size version? say like one paragraph long? lol

[Mgaz]

Originally Posted by suzublu

PM me your address & I'll send an ELM 327 I have spare

Really?
That is very kind

[Mgaz]

Originally Posted by suzublu

PM me your address & I'll send an ELM 327 I have spare

They arrived a couple days ago btw. Many thanks!

So far I've learned I'm boosting just under 16 psi on the ZS diesel and I have a maf low voltage error and another error code I'm not sure about.

Tried clearing them but they come back as soon as you turn the engine off and on again. (Funny cause that normally works on the computer! ) lol