Android / Beaglebone

Notes on Android OS

1. After downloading Android sdk linux, under "platform-tools" directory, the executable file "adb" is used in shell and then Android console is available. For this purpose, the usb connection was done and in the shell, inside the platform-tools directory:

./adb kill-server (server stop)

./adb devices (find the connected devices)

./adb shell (access to device console)

commands was typed. Thus, accessing the files in device is successful :)

2.  We planned to send and play some video files after some manipulation on them so that testing the video performance of the device. So the commands typed:

ffmpeg -i video.avi (gives the tecnical details about video.avi)

ffmpeg -i video.avi -ss 10 -t 20 -r 24 -b:v 1000k -minrate 1000k -s 640x360 -vcodec copy -acodec copy video.mp4 (arguments respectively; -ss starting time -t duration -r fps ratio -b:v bitrate ratio (as kB) -minrate minimum bitrate ratio (kB) -s resolution -vcodec video codec decision (the copy command means the original features of video copied as the same) -acodec audio codec decision (the copy command means the original features of audio copied as the same) and lastly video extension converted as mp4 )

3.  The manipulated videos are sent like the following:

./adb push /home/......../video.mp4 /mnt/...../Videos/ (firstly local pc directory and then device directory)

or

./adb pull /mnt/..../Videos/ /home/....../video.mp4 (firstly device directory and then local pc directory)

After starting the device, in gallery directory, in video file, you can see the manipulated video we have done.

4.  To test the ethernet, for the purpose of getting ip after entering into the console,

netcfg (determine if there is an ip address of device or not)

netcfg eth0 dhcp (if there is no ip, this command assigns an ip address automatically)

busybox ifconfig (shows assigned ip address )

5. After assigning an ip address, with the command   dd if=/dev/urandom/ of=a.log bs=1M count=16    an 16mB file consisting of random numbers , we created. The command   hexdump a.log | head    shows the inside of file. We zipped file with gzip a.log. The file is copied in the directory described in Nfs server :
cp a.log.gz /home/....../nfs  and then   mount 192.168.1.1:/home/..../nfs/ /mnt/net/   so we mounted the device. In console, with the command; busybox time busybox cp /mnt/net/a.log.gz /Somefile/  we got the copying time.

6.  In tmps (after mount command, we saw it),  dd if=/dev/zero of=silbeni bs=4096 count=1024  command was written. It means, we are running it in ram, so we can see the speed is rised. Moreover we realized that the bs and count values in command, is also an effective factor for the speed. When the device mounted, and we sent into the ram, the result we gathered was 10mB/sec and that was the expected one. :)