by Ryan Switzer

• Raspberry Pi 3
• Aftermarket head unit (Note: Must support Auxiliary input)
• Plugable USB Bluetooth 4.0 Low Energy Micro Adapter
• 2A Car Supply
• ELM327 Bluetooth Adapter
• PiCAN2
• DB9-to-OBD cable
• OBD Splitter
• RCA cable (+HDMI-to-RCA Adapter)
• Keyboard (*optional)

1. Insert the USB Bluetooth dongle into the Raspberry Pi along with the SD card.
2. Insert the OBD Splitter into the SAE J196216 (OBD Port) connector.
3. Insert the OBD-II Bluetooth adapter into the OBD Splitter.
4. Insert the DB9-to-OBD cable into the OBD Splitter.
5. Attach the PiCAN2 onto the Rasbeery Pi UART and connect to the DB9-to-OBD cable.
6. Connect you RCA cable to the back of your aftermarket head unit and plug the other end the converter and then into your Raspberry Pi.
7. Connect your 2A Car Supply to the Raspberry Pi and vehicle.
8. Finally turn your key to the ON position and navigate your head unit to Auxiliary input.

Before proceeding, execute the following:

$  sudo apt-get update
$  sudo apt-get upgrade
$  sudo apt-get autoremove
$  sudo reboot

Install dependecies using the following commands:

$  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 reboot

Next copy the source code over to the home directory via flash drive (or preffered file transfer means).

Copy, untar and register the rpi-can modules

$  cd /tmp; wget http://lnxpps.de/rpie/rpi-can-3.12.28+.tar.bz2
$  cd /; tar jxvf /tmp/rpi-can-3.12.28+.tar.bz2
$  depmod -a
$  reboot

Add the spi-config and mcp2515 modules

$  nano /etc/modules

Copy and paste the following

# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.
# Parameters can be specified after the module name.

snd-bcm2835
spi_bcm2708

# MCP2515 configuration for PICAN module
spi-config devices=\
bus=0:cs=0:modalias=mcp2515:speed=10000000:gpioirq=25:pd=20:pds32-0=16000000:pdu32-4=0x2002:force_release

# load the module
mcp251x

Update the raspi-backlist.conf

$  nano /etc/modprobe.d/raspi-blacklist.conf

Enable the spi-bcm2708 & mcp251x driver

# blacklist spi and i2c by default (many users don't need them)

#blacklist spi-bcm2708
blacklist i2c-bcm2708
#blacklist mcp251x

Reboot before configuring

$  reboot

Configure the CAN bus interface bitrate to 500kbs

$  ip link set can0 type can bitrate 500000

Enter your login credentials and execute (dependent on OS boot format):

$  startx

Launch BlueZ, the Bluetooth stack for Linux. Pair + Trust your ELM327 Bluetooth Adapter and Connect To: SPP Dev. You should see the Notification "Serial port connected to /dev/rfcomm0"

Note: Click the Bluetooth icon, bottom right (Desktop) to configure your device. Right click on your Bluetooth device to bring up Connect To: SPP Dev.

Open the terminal and enter the following:

$  cd pyobd-pi
$  sudo su
$  python obd_gui.py

Now use the Left and Right arrow key to cycle through the gauge display. (Note: Left and Right mouse click will also work)

To exit the program just press Control and C or Alt and Esc.

Data Logging If you would like to log your data run:

$  cd pyobd-pi
$  python obd_recorder.py

The logged data file will be saved under: /home/username/pyobd-pi/log/

Open the terminal and use the following commands to start dumping frames

$  ip link set can0 up
$  candump -cae can0,0:0,#FFFFFFFF