COM AM35 Linux

FAQ

Ethernet does not work

Check if the line "allow-hotplug eth0" in the file "/etc/network/interfaces" is activated. You can activate the ethernet interface on a running system with the command:

ifconfig eth0 up

Remark: To work with a nfs-rootfilesystem you have to disable the line "allow-hotplug eth0" in the file "/etc/network/interfaces". Maybe the system was prepared for this method for development and nobody did change it back.

How to set a Linux environment variable?

This example shows you how to configure the system to use a proxy-server with a environment variable.

export http_proxy=http://192.168.xxx.xxx:xxxx

How to schedule jobs to run periodically at certain times or dates?

You can use the cron daemon and/or anacron. To use anacron you have to copy or link your program or script into one of the the following folders:

/etc/cron.hourly

/etc/cron.daily

/etc/cron.weekly

/etc/cron.monthly

For further information have a look at the general linux documentation.

Debian system

Calibrating the touchscreen

ts_calibrate

Check the enviroment variable "TSLIB_TSDEVICE=/dev/input/event0" with printenv if an error occurs.

Running Qt Demos

cd /usr/qt/demos/demoname

demoname -qws

For the Qt-Browser change demoname to browser

If the touchscreen does not work please check the enviroment variable "QWS_MOUSE_PROTO=Tslib:/dev/input/event0" with printenv.

Run Qt demos with powerVR (3d acceleration) support:

cd /usr/qt/demos/embedded/demoname

demoname -qws

Run demos with a usb-mouse as input device:

cd /usr/qt/demos/demoname -qws

/QWS_MOUSE_PROTO=Auto:/dev/input/mice demoname -qws

Remark: Just remember that you need to run the Qt demos with the options -qws. Omitting -qws results in the app waiting to connect to the QWS Server, which is not running.

Login/Shutdown system

Username:	root
Password:	foo

shutdown -h now

How to control the GPIOs

DHCOM Name:	alt. DHCOM Name:	SO-DIMM Pin#	Linux <GPIO#>
GPIO A		154	116
GPIO B		156	117
GPIO C		162	118
GPIO D		163	119
GPIO E		164	125
GPIO F		165	140
GPIO G		167	141
GPIO H		173	155
GPIO I		175	152
CIF HSYNC	GPIO J	74	96
CIF PCLK	GPIO K	72	94
CIF MCLK	GPIO L	70	58
CIF VSYNC	GPIO M	68	97
CIF D9	GPIO N	66	98
CIF D8	GPIO O	64	95
CIF D7	GPIO P	62	106
CIF D6	GPIO Q	60	105
CIF D5	GPIO R	58	104
CIF D4	GPIO S	56	103
CIF D3	GPIO T	54	102
CIF D2	GPIO U	52	101
CIF D1	GPIO V	50	100
CIF D0	GPIO W	48	99

Remark: Depending on your board configuration some of the additional gpios shared with the camera interface are not available on your system.

Export

echo <GPIO#> >/sys/class/gpio/export

Remark: Have a look into /sys/class/gpio/ for already configured gpios.

Set direction

echo in >/sys/class/gpio/gpio<GPIO#>/direction

echo out >/sys/class/gpio/gpio<GPIO#>/direction

Set state

echo 0 >/sys/class/gpio/gpio<GPIO#>/value

echo 1 >/sys/class/gpio/gpio<GPIO#>/value

Initialize and test CAN

Initialize:

ip link set can0 up type can bitrate 500000

Send test message via cansend (part of can-utils):

cansend can0 100#11.2233.44556677.88