I have made a new release of the CarPC software for Raspberry PI. Updates: - RDS radio support(new radio application) - new application for managing everything on GPIO which takes about 3% of cpu(gpio interrupts are now used instead of polling mechanism) - new FM Radio XBMC addon - kernel 3.17.0 - optimised Navit and XBMC priorities to remove hang times
Minor issues: [Radio FM addon]: I tried different ways to set the height of the height of an item in xbmcgui.ControlList but it seems that nothing is working(I have tried adding as a parameter and also using setItemHeight). If you have any other idea please let me know.
In order to have RDS working pin22(GPIO25) from RPI should be connected to Radio(SI4703) GPIO2 pin. This is the full schematic for one SI4703 radio module and two rotary encoders:
Installation instructions are in the README inside the archive. Don't forget to(sudo apt-get update & sudo apt-get upgrade). For any issues please use the Forum to avoid filling this blog with comments.
Have fun and keep your eyes on the road while driving!
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 http://www.raspberrypi.org/downloads/ - 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 ./carpc-install.sh 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/speech.sh 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(http://engineeringdiy.freeforums.org/). Due to this, comments on this blog will be disabled.
After installing the image on an sd card, you have to configure the system for your needs.
Calibrate the touch screen The touch screen calibration involves two steps and you need a keyboard connected: 1. Calibrating the touch screen for X11 applications(like Navit). Open the terminal from Desktop and type xinput_calibrator and follow the indications. After the calibration is completed you have to put the output in a file to make this permanent: sudo nano /usr/share/X11/xorg.conf.d/01-input.conf Put here the output of xinput_calibrator. It will be something like: Section "InputClass" Identifier "calibration" MatchProduct "eGalax Inc. USB TouchController" Option "Calibration" "121 1917 317 1741" Option "SwapAxes" "1" EndSection 2. Calibrating the touch screen for XBMC. In XBMC use the keyboard to go to Programs/Touch Screen Calibration and follow the informations on screen. Note, that in order to make a better calibration you can move the finger on screen towards the point, before pressing enter(as can be seen on minute 0:52 in the video). Touch each point and then press enter to go to the next one. At the end, you have to unplug the touch from usb and then plug it back(works on XBMC Gotham). After this, he calibration is stored permanently in the file /home/pi/touchscreen_axes_calib. You can edit this file to fine tune the position of the cursor if the calibration isn't perfect. calib_x_d and calib_y_d - control the cursor displacement up/down/left/right calib_x_fact and calib_y_fact - some factors obtained in the calibration process(don't edit them) click_confines - defines the area that will be used for click(if the touch moves outside of this area then a drag action will occur) - this area is measured from the first touched point touch_mouse - if you want to use a mouse you have to set this to 0, but some touch screens behave as mouses and you have to set this to 1 in order for them to work(with single click). For the most of the touches this can be 0 if you want to also use a mouse, but if you don't want to use a mouse it doesn't mater, let it be 1.
Change the resolution [XBMC] Using ssh you have to edit the file /home/pi/.xbmc/userdata/advancedsettings.xml and set your resolution. After this restart the whole system and XBMC should run with your new resolution. [LXDE] Connect with ssh and type tvservice -mDMT && tvservice -mCEA and get the desired resolution mode Edit /boot/config.txt and modify according to your preference, for example: hdmi_group=2 hdmi_mode=27 CEA group is 1 and DMT 2.
Add a new map for Navit 1. Go to Navit Planet Extractor and download a .bin file for your area. 2. Copy the .bin file in your RPI card in /home/pi/.navit/ folder 3. Edit the file /home/pi/navit_src/build/navit/navit.xml and search for the entry: <mapset enabled="yes"> <map type="binfile" enabled="yes" data="/home/pi/.navit/Romania.bin"/> </mapset> 4. Add your map name here like this: <mapset enabled="yes"> <map type="binfile" enabled="yes" data="/home/pi/.navit/Romania.bin"/> <map type="binfile" enabled="yes" data="/home/pi/.navit/new_map.bin"/> </mapset>
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/speech.sh 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. To enable this controller, you have to edit the file /home/pi/StartCarPC and search for the entry: # Start the GPIO Remote #sudo opencarpc-controller /home/pi/gpio_description & You have to change it to: # Start the GPIO Remote sudo opencarpc-controller /home/pi/gpio_description & Now, you can set the configuration file like in this post
Change the car logo in the Home screen If you want to put another car logo you have to edit the file /home/pi/.xmc/addons/skin.CarPC-touch/16x9/Home.xml and find the entry: <posx>580</posx> <posy>205</posy> <width>550</width> <height>550</height> <texture>bmw_logo.png</texture> Here, you can set your new image instead of bmw_logo.png you can put a complete path of the new image.
Set up a WIFI connection If you want to have internet connection, or airplay or control the whole system using the XBMC remotes, you have to setup a wifi hotspot with your phone and then use an USB WIFI dongle(I am using EDIMAX EW-7811UN dongle). The system is configured to automatically connect to a wifi hotspot with the following settings: wpa-ssid "opencarpc" wpa-psk "opencarpc123" You can find these settings in the file /etc/network/interfaces.
I have worked on some new features for my CarPC. Here are the changes: First, some videos:
The latest image can be downloaded from the Downloads link on the right of this blog(username:pi, password:a). Note! If you do not have any rotary encoder connected or any buttons with a resistor you need to disable the carpc-controller application. You can do this by editing the file /home/pi/StartCarPC and commenting the line which contains carpc-controller.
Hardware updates: - added ViewHd HDMI to HDMI+audio board - added SI4703 FM Radio module - created an expansion board with fm radio module and three connectors(one for GPS receiver and two for rotary encoders) - added a very cheap board to mix two output channels(RPI and radio) into a single output(which goes to the amplifier, in my case AUX input of the car player)
Software updates: - added loading movie(created by Doru Ignat) - added a python server responsible for controlling the radio module via i2c - added new XBMC plugin for controlling the FM Radio(including storing up to 5 radio stations in a file) - improved carpc-controller to support sending multiple commands for a single button press or encoder turn(e.g. turning right one rotary encoder can increase the volume in XBMC and the volume of radio at the same time) - improved the speed in Navit clicking - improved the Navit OSD for both day and night setup(Navit switches automatically teh setup based on the time of the system). - added time synchronization mechanism based on GPS readings(RPI does not have a real time clock)
The expansion board.
RE1 and RE2 are rotary encoders.
The FM Radio driver and Python server. The FM Radio module is connected using i2c communication interface(GPIO0-SDA and GPIO1-SCL of the PI). The radio driver is contained in the si4703 python class. The Radio server is implemented in the file radio_server.py(which is automatically started at boot time). This server simply opens a socket and waits for data. After any data is received, a couple of if-else statements different radio functions are called base on the incoming data. The available commands are:
seek_right - search for a new station in the right of the current frequency seek_left - search for a new station in the left of the current frequency tune_xx.x - set the current frequency to xx.x MHz volume_xx - set the volume of the radio module to xx. xx should be between 0 and 15 toggle_mute - toggle mute get_frequency - get the current frequency
The server reply with the current frequency for each command.
Simple test. To understand how this radio server-client works you can make the folowing experiment: 1. Plug the gpio expansion board(or wire the radio module to the PI as in the above schematic) 2. [Server] Connect using one ssh window(I use Putty) to the PI and enter the folowing commands: cd radio sudo python radio_server.py The radio server should initialize the radio module and start the server. 3. [Client] go to the radio folder and use radio_client.py to send commands o the radio server, like in the folowing picture:
The file radio_client.py simply opens an UDP socket, puts an '_' character between arguments and send the obtained string to the server socket.
The radioFM XBMC plugin. In order to simplify user interaction I have created a new XBMC plugin(radioFM). Its purpose is to allow interacting with the Radio Server(and with the Radio Module) using the touch screen. In order to be able to use this plugin you need to have the radio_server.py started and the FM module plugged in.
Features:
The current frequency is displayed at the top.
The left and right arrow buttons are for seeking to the next channel(left or right).
The bottom 5 buttons are preset channels(these are kept in a file so they are available after reboot).
The Set/Tune Channels button is used for changing the mode in which the bottom buttons are operating. By default they are in the 'Tune' mode, so if you presss them the radio will tune to that frequency. If you press the Set/Tune Channels button once you will enter the Set mode, which will allow you to store the current channel in which preset button you like(or in all of them... if you want) by pressing it once. You will see that the frequency will be changed.
Connecting two audio sources(RPI and Radio) to one amplifier. In order to correctly hook up two audio sources together(putting them in parallel) for a single output you have to use one schematic from this document. I have used the last schematic. Don't forget to use at least 1% tolerance for the resistors. The new GPIO controller. The GPIO controller is now using the official XBMC client code from xbmcclient.h. Now, you can call a lot more XBMC functions for any button pressed or encoder movement.
TODO List: - update to the latest Raspberry PI firmware(today it is possible but then Navit won't be visible) - remove the calibration file for XBMC(/usr/share/eGalax/touchscreen_axes_calib) and use the values from the Debian calibration file(/usr/share/X11/xorg.conf.d/01-input.conf) - create an XBMC addon to allow calibrating the touch screen for both XBMC and X11 windows and also for calibrating the external encoders and button - create a configuration page(XBMC addon) for the carpc-controller settings - create a better audio mixer unit - create a new page for launching different X11 applications
I have recently worked on adding external controls for my Raspberry PI CarPC project because while driving it is better to have some physical controls to rely on, rather than looking at the touch screen to find the buttons. This post provide information on how to set up buttons or rotary encoders to control XBMC from Raspberry PI.
Rotary encoder
Rotary encoders are very cheap and very nice controls(eBay link). You can find them in car stereos for volume control. You can also use them to browse through menu items or to skip to next song etc. They are looking very similar to a potentiometer, but there are major differences: they can be turned in both directions with infinite steps(you know just the direction of the spin), they provide digital output, a full rotation have a number of steps and they have push button also. Connections for Raspberry PI should be done as follows: + pin to 3.3V GND pin to Raspberry PI GND SW to one GPIO CLK and DT to two GPIOs When the push button is pressed the pin labelled SW is connected to GND. This can be set up as any push button(see below).
Push button
A push button can have two states on or off. There are two ways to hook up a button to a logical circuit(e.g Raspberry PI GPIO's):
We have to use the first setup(with pull up resistor) for the tool to work properly. So, for the push button of the rotary encoder above, we have to cable it like this:
The tool I have created a tool to allow you interface rotary encoders(and also push buttons) with Raspberry PI GPIO's. Also you can set an XBMC command to be executed for click, left rotation and right rotation. The tool can be otbained from my Google Code project(link to page). It is very easy to use it. You just have to accomplish two steps: - copy rpi-xbmc-remote in a place where it can be accessed from anywhere(e.g. /usr/bin) - call it using sudo rpi-xbmc-remote /path/to/configuration/file
The configuration file Example:
ip:localhost
button:7:KB:return
encoder:clk:23:KB:up:dt:24:KB:down
The configuration file can reside anywhere on the disk. It provides a way to define two kind of inputs for XBMC: regular button and rotary encoder.Lines should be less than 100 characters in length. Lines starting with # are comments and are not being processed.
Example of regular button definition:
button:7:KB:return
- 'button' means it is a regular button
- '7' means use GPIO7 for this button
- 'KB' means XBMC device map
"KB" - Standard keyboard map
"XG" - Xbox Gamepad
"R1" - Xbox Remote
"R2" - Xbox Universal Remote
"LI:devicename" - valid LIRC device map where 'devicename' is the actual
name of the LIRC device
- 'return' means XBMC button name to be called(see XBMC keymaps)
Example of rotary encoder definition:
encoder:clk:23:KB:up:dt:24:KB:down
- 'encoder' means it is a rotary encoder
- '23' means use GPIO23 for rotary encoder CLK
- 'KB' means XBMC device map for rotary encoder left turn(same as above)
- 'up' means XBMC button name to be sent for left turn of the rotary encoder
- '24' means use GPIO24 for rotary encoder DT
- 'KB' means XBMC device map for rotary encoder right turn(same as above)
- 'return' means XBMC button name to be called(see XBMC keymaps)
Keep in mind!
You have to put a pull up resistor for every push button you define in the configuration file. If you don't do this then the state of the button will be variable when not pressed(it will oscillate between 0 and 1) and it will behave like it is pressed randomly.
