What You Need
To complete this project, you need:
An old Android phone you aren’t using anymore. A Bluetooth or WiFi ELM 327 scan tool device. An FM modulator or transmitter or a head unit with an aux input. A mount to hold your phone in place. An OBD-II interface app. Navigation and entertainment apps.
How to Turn an Android Phone into an Infotainment System
Once you’ve gathered your materials, follow these steps to connect your Android phone to your car. The first place to look is under the dash to the left or right of the steering column. You may find the connector right up front or mounted back near the firewall. In cases where you feel that you may kick the device when getting in and out of the car, it is essential to go with a low-profile device rather than accidentally damaging your OBD-II connector. You may also want to try out a free version first to make sure that the app will run on your phone and connect to your ELM 327 device. Unfortunately, even if the Google Play store says that an app will run on your phone, you may find that it refuses to pair with your scan tool. Many Bluetooth car kits achieve this same primary type of functionality, and you may be able to use your Android phone for hands-free calling if it still has an active voice plan. The result won’t match the kind of functionality you get out of a fancy new OEM infotainment system, but you can get fairly close without spending a lot of money.