Template:FriendlyCoreAllwinnerH3

1 Connect to DVP Camera CAM500B

The CAM500B camera module is a 5M-pixel camera with DVP interface. For more tech details about it you can refer to Matrix - CAM500B.
connect your H3 board to a CAM500B. Then boot OS, connect your board to a network, log into the board as root and run "mjpg-streamer":

$ cd /root/mjpg-streamer
$ make
$ ./start.sh

The mjpg-streamer application is an open source video steam server. After it is successfully started the following messages will be popped up:

 
 i: Using V4L2 device.: /dev/video0
 i: Desired Resolution: 1280 x 720
 i: Frames Per Second.: 30
 i: Format............: YUV
 i: JPEG Quality......: 90
 o: www-folder-path...: ./www/
 o: HTTP TCP port.....: 8080
 o: username:password.: disabled
 o: commands..........: enabled

In our case the board's IP address was 192.168.1.230. We typed 192.168.1.230:8080 in a browser and were able to view the images taken from the camera's. Here is what you would expect to observe:

mjpg-streamer是用libjpeg对摄像头数据进行软编码，Linux-4.x内核的ROM目前并不支持视频硬编码, 但是如果使用Linux-3.x内核的ROM的话, 则可以使用ffmpeg对摄像头数据进行硬编码，这样能大大降低CPU的占用率并提高编码速度:

$ ffmpeg -t 30 -f v4l2 -channel 0 -video_size 1280x720 -i /dev/video0 -pix_fmt nv12 -r 30 \
        -b:v 64k -c:v cedrus264 test.mp4

By default it records a 30-second video. Typing "q" stops video recording. After recording is stopped a test.mp4 file will be generated.

2 Connect to USB Camera(FA-CAM202)

The FA-CAM202 is a 200M USB camera, 连接测试USB摄像头的方法请参考 <连接DVP摄像头模块(CAM500B)> 章节。
请自行修改start.sh, 确保使用正确的/dev/videoX节点, 下列命令可以用来确定FA-CAM202摄像头的video节点:

$ apt-get install v4l-utils
$ v4l2-ctl -d /dev/video1 -D
Driver Info (not using libv4l2):
        Driver name   : uvcvideo
        Card type     : HC 3358+2100: HC 3358+2100
        Bus info      : usb-1c1b000.usb-1
	...

3 Check CPU's Working Temperature

You can use the following command to read H3's temperature and frequency

cpu_freq

4 Check System Information with Rpi-Monitor

Our OS contains the Rpi-Monitor utility with which users can check system information and status.
In our case our board's IP was 192.168.1.230 and we typed the following IP in a browser:

192.168.1.230:8888

We were directed to the following page:

Users can easily check these system information and status.

5 测试看门狗

使用下列命令可以测试看门狗功能:

$ cd /root/demo/watchdog/
$ gcc watchdog_demo.c -o watchdog_demo
$ ./watchdog_demo /dev/watchdog0 10
Set timeout: 10 seconds
Get timeout: 10 seconds
System will reboot in 10 second

6 Access GPIO Pins/Wirings with WiringNP

The wiringPi library was initially developed by Gordon Henderson in C. It contains libraries to access GPIO, I2C, SPI, UART, PWM and etc. The wiringPi library contains various libraries, header files and a commandline utility:gpio. The gpio utility can be used to read and write GPIO pins.
FriendlyElec integrated this utility in FriendlyCore system allowing users to easily access GPIO pins. For more details refer to WiringNP WiringNP

7 Run Qt Demo

Run the following command

$ sudo /opt/QtE-Demo/run.sh

Here is what you expect to observe. This is an open source Qt Demo: