Sunday, September 28, 2014

Raspberry PI CarPC September 2014 updates


I have made some progress on my CarPC project and here are the main changes:
- support for Raspberry PI Model B+
- update XBMC to 13.2 stable
- update kernel to 3.16.0
- reworked radio(rds is available but not yet enabled because of some high cpu usage - will fix this shortly)
- update system available(only ~150MB for download instead of a whole image)
- file system restructuring
- new skin
- forum released(Engineeryng-Diy Forum)

First of all the installation process(this is only for a fresh install, update coming soon):
- write a fresh image with the latest Raspbian from
- copy the carpc folder in /home/pi/ on the SD card(gt this folder from my Downloads page/updates)
- plug the image in RPI and start it
--- use the auto menu to expand file system
--- change password to 'a'
--- enable boot into desktop-> Desktop Log in as user 'pi' at the graphical desktop
--- enable ssh, disable overscan, disable serial messages
--- Change Internalisation Options -> Locale and Timezone to your country
- connect a keyboard and open the terminal or connect using ssh
- change user permissions for pi: sudo chmod -R a+rwx /home/pi
- type cd /home/pi/carpc/ and then ./ and then wait for the system to install
Note! If you get Cannot mkdir: Permission denied running this script then you should type sudo chmod -R a+rwx /home/pi/carpc/ and then run the script again.
- after this, you should reboot(sudo reboot)

Calibrate the touch screen
Forget about xinput-calibrator and X11 calibration metods.
If you have calibration file(/home/pi/touchscreen_axes_calib) from a previous installation you can use it.
If you don't, then use the touch screen calibration plugin. This plugin works if you set correctly the Raspberry PI resolution in /boot/config.txt. Follow the steps in this video.

Add a map for navigation
Go to Navit Planet Extractor and download a .bin file for your area.
Copy the .bin file in your RPI card in /home/pi/.navit/ folder. Rename the .bin file to map1.bin, map2.bin, map3.bin or map4.bin.

Setup the GPS receiver
  1. For USB devices. After plugging the device into the usb port type dmesg and you should see somewhere that a new device was mapped on /dev/tty... Most probably the file name would be /dev/ttyACM0.
  2. For Serial(UART) modules. The device will have the file name as /dev/ttyAMA0.
You can test that the device is connected to a file name by calling cat/dev/ttyAMA0, for example and you should see some NMEA output.
Now, copy this file name and put it in the file /home/pi/StartCarPC in the section:
    # Start gpsd
    # /dev/ttyAMA0 - RPI serial port
    # /dev/ttyACM0 - usb port
    sudo killall gpsd
    gpsd /dev/ttyAMA0

Voice configuration for Navit
Each time a road indication has to be made, Navit will execute the file /home/pi/.navit/ with the indication text. This file will play a sound and the speak the indication, through speakers.
    aplay -r 44100 /home/pi/.navit/notification3.wav & sleep 0.7 && espeak -ven+f4 -s150 -a 150 -p 50 "$1" --stdout | aplay
    /home/pi/.navit/notification3.wav - the sound that will be played each time before an indication
    -ven+f4 - female voice number 4
    -s150 - speed 150 words per minute
    -a150 - amplitude
    -p50 - pitch
You can find more settings in the espeak manual
If you don't want the voice guidance you can press the speaker button in Navit and it will be turned off.

Configure the Controller
The controller can be easily used with Steering wheel controls or other physical controls in your car.
You can set the configuration file like in this post.

Change the car logo in the Home screen
The car logo is a png file in /home/pi/config/logo.png.

New skin
Thanks to Doru, a new skin is available: CarPC-touch_carbon.

Comments moving to forum
From now on, a forum is available for any issues/suggestions( Due to this, comments on this blog will be disabled.

Have fun!