How to communicate with OBD II using bluetooth or wifi using iphone

Dax picture Dax · Jul 14, 2014 · Viewed 10.5k times · Source

I like to create a simple application for iOS, which read data from car through ODB II Wifi/bluetooth device and display in iPhone screen. But i don't know where to start. Please somebody help me to achieve below results.

I have both Bluetooth and wifi dongle.

Step 1 : Pair the bluetooth or Wifi dongle and iPhone.

Step 2 : Read the details through dongles

Please refer any tutorial or sample code which i can understand easily. I want to understand the these process in-depth and want to code by myself. So please help.

Thanks in advance.

Answer

psci picture psci · Jul 14, 2014

As David mentioned, on iOS you can use WiFi OBD interface only. Standard Bluetooth (not BTLE) will not work. Bluetooth devices should be approved by Apple to be able to transfer data to/from iOS. AFAIK there is no such a OBD's.

Probably your OBD dongle is based on ELM327 chip. Good starting point is this doc. Read it carefully. This is everything what you need. Interesting things starts at page 7.

On iOS you should open TCP connection with your OBD IP address(for example using NSInputStream, NSOutputStream), then configure OBD using AT commands. Rest is described in section "Talking to the Vehicle" (page 30) in ELM link. Enjoy reading :)

If you need more help- just ask.