I've found a number of apps for the iPhone/iPad that connect to ODB-II readers via WiFi, but unfortunately that means that it disables 3G and all the benefits of having a 3G device built into my dash.
I can't seem to find any apps that work via Bluetooth instead of WiFi.
Do any of you know if there is one available?
ELM327 is not supported by iPhone as Apples Bluetooth Stack does not support the Bluetooth Serial protocol, the ELM327 is in it's simplest form a ODB to Serial Adapter with the serial data fed to a Bluetooth modem.
Well, It's not necessarily dealing with the ELM327, but this looks like a FANTASTIC solution.
Griffin CarTrip
No longer getting developed.
Apple is currently not allowing developers to use Bluetooth for this purpose. The only real connection is via Wifi.
My initial "assumption" was that if you're connected via Wifi, then your 3G data is disabled and therefore you cannot use data while using the OBD-II dongle. This information is wrong. If you put your data connection in proxy mode, your phone will still connect to data through 3G, even when connected to the dongle.
This works very well except for the minor issue whereby the gauges poll once every second as opposed to constantly polling in real time with what's actually happening. This makes for a choppy user experience, but it still works well.
Apple will not let you connect to the ELM 327 Bluetooth Interface as the manufacturer has not paid APPLE to support their bluetooth stack. Gotta Love EM'
There are plenty of apps for the Android that work well with the ELM 327 Bluetooth modules.
The accepted answer describes the situation as of iOS 5 and below.
Since 2014, iOS comes with the CoreBluetooth framework which allows communication with BTLE (Bluetooth Low Energy aka 4.0) devices. These days, you can find a lot of adapters supporting this communication standard – make sure that it is not a Bluetooth 3.x adapter, these will not work.
As for iOS applications, unfortunately not many do support BTLE yet at all. Those which do mostly require their branded adapter. There are only a few which claim to work with almost any BTLE-compliant adapter, e.g. OBD2 Expert (Disclaimer: I'm the author).
