RPi

2016-04-19T10:46:03Z

Minwi: Added how to autostart gimx at boot and flash a led when running

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'''Warning: RPi support should be considered as experimental. Be prepared to face issues if you try GIMX on the RPi.'''

GIMX can run on many Linux targets, and the [http://www.raspberrypi.org/ the Raspberry Pi] is one of them!
== Hardware considerations == 


Use a USB HUB only if there are no ports available on the RPi. 
It is highly recommended to use a HUB with an external power supply.

== Firmware update == 
As early firmwares had severe USB issues it is recommended to update the firmware before using GIMX. 
Updating the firmware may also be useful if you plan to use a Logitech force feedback wheel (the uhid kernel module was missing in earlier firmwares). 
Type the following command:
<pre>sudo rpi-update</pre>
And don't forget to reboot:
<pre>sudo reboot</pre>
Tested Rpi firmware:
<pre>pi@raspberrypi ~ $ uname -a
Linux raspberrypi 4.1.9+ #819 PREEMPT Thu Oct 1 20:31:26 BST 2015 armv6l
GNU/Linux</pre>


== USB adapter using the on-board UART interface == 

=== Hardware requirements === 


The on-board UART runs at 0V/3.3V levels, and the AVR USB board has to run at 5V to operate at 16MHz (running at 3.3V would only allow to operate at 8MHz). 
Connecting the RPi and the AVR USB board directly may damage the hardware! 
One cheap solution is to use a voltage divider: 
* Connect both GNDs
* It's safe to connect the TXD pin of the RPi to the Rx pin of the AVR USB board (the GIMX firmwares configure the Rx pin as an input)
* To connect the Tx pin of the AVR USB board to the RXD pin of the RPi, you'll need to convert the voltage level from 0..5V to 0..3.3V. 
This can be done with a simple resistive divider:
<div class="image200px">[http://gimx.fr/img/wiki/Resistive_divider.png http://gimx.fr/img/wiki/Resistive_divider.png]</div>
Vin is the Tx pin of the AVR USB board, Vout is the RXD pin of the RPi, R1=2.2kΩ , R2=3.3kΩ
* Do not connect any other pin!

=== Sotware adjustments === 


By default, the RPi UART is configured as a serial console. 
Disable this serial console using raspi-config:
<pre>
sudo raspi-config
</pre>
Then select:
<pre>
"Advanced Options", "Serial", "No", "Finish"
</pre>
The default configuration does not allow high baudrates. 
Enable high baudrates editing /boot/config.txt:
<pre>
sudo nano /boot/config.txt
</pre>
Add the following line at the end of the file:
<pre>
init_uart_clock=8000000
</pre>
Reboot to apply the changes:
<pre>
sudo reboot
</pre>

== GIMX installation == 
<pre>sudo apt-get install gdebi
wget http://gimx.fr/download/gimx-raspbian -O gimx.deb
sudo gdebi gimx.deb</pre>


If you get a "Dependency is not satisfiable: ..." error message, upgrade Raspbian:
<pre>sudo apt-get update && sudo apt-get upgrade</pre>

== Stop/disable triggerhappy service == 
[https://github.com/wertarbyte/triggerhappy/blob/master/README Triggerhappy] is a daemon that opens every input device for reading, and that consumes a few percent of the CPU time.


It seems a good idea to stop it while running GIMX.


To stop triggerhappy:
sudo service triggerhappy stop
To disable triggerhappy:
sudo update-rc.d triggerhappy disable

== Run GIMX == 
Read the [[Quick_Start|Quick start page]] to learn how to run GIMX through the GUI. 
A good idea is to run GIMX directly from a terminal, without starting a graphical session, which can be done over the network, using a ssh client, or you can [[#Autostart GIMX at boot without GUI]] 
Ideally, GIMX should be launched without using the Ethernet port (because it is connected on the USB bus). 
More details on command line options on [[Command_line|this page]]. 

== Autostart GIMX at boot without GUI ==
Simply create a file /etc/systemd/system/gimx.service (as root) with the following content:

<pre>
[Unit]
Description=GIMX
After=syslog.target network.target

[Service]
User=pi
Type=simple
ExecStart=/usr/bin/gimx -p /dev/ttyUSB0 -c LogitechDrivingForceGT_G29.xml --nograb
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target
</pre>

Replace ttyUSB0 with your device and LogitechDrivingForceGT_G29.xml with your mapping file (which should be available in the pi home directory as /home/pi/LogitechDrivingForceGT_G29.xml)

Run <pre>sudo systemctl daemon-reload</pre> to notify systemd about the new file and <pre>sudo systemctl enable gimx && sudo systemctl start gimx</pre> to enable the gimx service start at boot and start it in the same line.

== Notify when GIMX is running using a led ==
In order to have a proper confirmation about if the gimx service is up and running, you can add a simple python script that turns a led on if the gimx service is running.

The file will be located at /home/pi/blink.py:

<pre>
#!/usr/bin/python
import os
import time
import RPi.GPIO as GPIO

led = 23
button = 18
GPIO.setmode(GPIO.BCM)
GPIO.setup(led, GPIO.OUT)
GPIO.setup(button, GPIO.IN, pull_up_down = GPIO.PUD_UP)

def Shutdown(channel):
GPIO.output(led, True)
time.sleep(0.2)
GPIO.output(led, False)
time.sleep(0.2)
GPIO.output(led, True)
time.sleep(0.2)
GPIO.output(led, False)
os.system("sudo shutdown -h now")

GPIO.add_event_detect(18, GPIO.FALLING, callback = Shutdown, bouncetime = 2000)

while True:
found = False
time.sleep(5)
pids = [pid for pid in os.listdir('/proc') if pid.isdigit()]
for pid in pids:
try:
cmd = open(os.path.join('/proc', pid, 'cmdline'), 'rb').read()
if "gimx" in cmd:
found = True
except IOError: # proc has already terminated
continue
if found == True:
GPIO.output(led, True)
else:
GPIO.output(led, False)
</pre>

As a bonus, you can add a button so when it is pressed, there is a little blink effect, and the pi is shutted down.

<-- missing diagram -->

To start at boot, simply add it to the pi user crontab (crontab -e) as <pre>@reboot /home/pi/blink.py</pre>
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GIMX - User contributions [en]

RPi