Following Paul’s tutorial , we detail the steps to make pcDuino display car diagnostic (OBS_II) data.  In this post, you will learn how to use Bluetooth 4.0 USB dongle on pcDuino, and use it to connect to OBD-11 adapter to retrieve real time engine data and display them.

Hardware Installation

Locate the SAE J196216 (OBD port) connector on your car, which is usually in the drivers cabin. The following is a picture of the ODB connector.

Connect the ELM327 OBD2 to the OBD connector:

On the pcDuino side, we need to connect the Bluetooth 4.0 USB dongle to pcDuino3 USB port. We can use a USB hub if the USB port is not enough.

Software Installation

The software installation is pretty straightforward.  First, we need to run:

$ sudo apt-get update

Next, we are going to install the python and Bluetooth tools:

$sudo apt-get install python-serial
$sudo apt-get install bluetooth bluez-utils blueman
$sudo apt-get install python-wxgtk2.8 python-wxtools wx2.8-i18n libwxgtk2.8-dev
$sudo apt-get install git-core

To download the OBD python code, we use the following command:

$ git clone https://github.com/Pbartek/pyobd-pi.git

Bluetooth Pairing and Serial Port

Now we are going to look at how to pair bluetooth. Before we do that, we need to run ‘$su’ to switch to root user.  Please refer to this post if you don’t know how to do that.

We navigate to the menu, and select Bluetooth manger:

Right click the first device, and choose ‘Connect’. It will show up as:

Now right click the OBD11, and click ‘Pair’. It will ask for password, please enter ‘1234’.  After that, right click OBDII again, and click ‘Port’:

Now the buletooth serial port is accessed as ‘/dev/rfcomm0’.

Run OBD GUI:

To run OBD GUI, we just do:

$ cd pyobd-pi
$ python obd_gui.py

The following is the screen displaying the data: