Remote Control using Telnet

From NMTWiki

If you want to build an application that controls your NMT you can use a plain telnet connection and execute the following commands. Needless to say, before you can use any of these commands you need to install a telnet server on the NMT.

Contents 1 Remote control emulation 2 Telling Gaya to navigate to an URL 3 Manually starting a media file 3.1 Stopping all application before starting a media file 3.2 Starting the media player using nohup 3.3 Restarting Gaya after playing a media file 3.4 Example

Remote control emulation

You can emulate the IR remote control that came with the NMT. This works for all applications.

echo KEYCODE > /tmp/irkey

Replace the string KEYCODE with any of the following key codes:

Command	Key code	Command	Key code
Play	$((0xE9))	Pause	$((0xEA))
Stop	$((0x1B))	OK	$((0x0D))
Up	$((0xA8))	Down	$((0xA9))
Left	$((0xAA))	Right	$((0xAB))
Back	$((0x8D))	Menu	$((0x09))
Home	$((0xD0))	Rewind	$((0xD5))
Forward	$((0xD6))	Previous	$((0xDB))
Next	$((0xDC))	Subtitle	$((0xEB))
Audio	$((0xD8))	Info	$((0x95))
Setup	$((0x8C))	Source	$((0xDD))
Power	$((0xD2))	Red	$((0xDE))
Green	$((0xDF))	Yellow	$((0xE0))
Blue	$((0xE2))	Del	$((0x08))
Caps	$((0xFC))	Timeseek	$((0x91))
Zoom	$((0xDA))	Repeat	$((0x90))
Angle	$((0xEC))	TV Mode	$((0x8F))
Eject	$((0xEF))	Volume Up	$((0x9E))
Volume Down	$((0x9F))	Mute	$((0xE1))

The keycode for the numeric keys is 0xF1 + the number of the key. For example the key 0 is $((0xF1)), the key 1 is $((0xF2)), 2 is $((0xF3)), etc. These codes act just like the keys on the IR remote. If you press a key multiple times it will replace the number with an alphanumeric character.

If you want to emulate a keyboard you can send the value of the ASCII characters. You can use the decimal values as the key code, or use the hexadecimal value and write it like $((0xAA)).

Telling Gaya to navigate to an URL

You can instruct Gaya - the HTML browser and responsible for the main user interface - to navigate to an external or internal URL.

echo -n "http://localhost:8883/start.cgi" >> /tmp/gaya_bc

Manually starting a media file

It is possible to manually start playing a media file or DVD image.

To start a DVD use the following command:

amp_test /path/to/file --dfb:quiet -osd32 -bgnd:/bin/logo.jpg

To play a MP3 track

mono -audio -prebuf 100 -bgimg -single /path/to/file -dram 1

To play a video file

mono -nogui -single /path/to/file -dram 1

To play a playlist of audio files

mono -audio -bgimg -playlist /path/to/playlist -dram 1

Stopping all application before starting a media file

If you start playing a file while another file is already playing or Gaya is running, you are going to cause a lot of problems and make the NMT very unstable.

To prevent these problem you need to stop all applications before running the command above.

echo 212 > /tmp/irkey
sleep 1
killall mono
killall pod
killall gaya
killall amp_test
sleep 1

Starting the media player using nohup

If you execute one of the commands above you will notice that you no longer can emulate the remote control. This is because the commands above keep running and do not return to the command line until playback of the files has finished.

To solve this problem you need a small tool called nohup. Unfortunately nohup is not part of the firmware. It is part of busybox26 which is commonly used to provide telnet access to the NMT. If busybox26 is not present on the NMT, your application need to install a copy.

/bin/busybox26 nohup mono -nogui -single /path/to/file -dram 1 > /dev/null 2>&1 &

Restarting Gaya after playing a media file

Another problem you may run into is that Gaya does not restart after playing the file.

To make sure that Gaya restarts you need to create a shell script that runs the mono command and restarts gaya afterwards.

echo "mono -nogui -single /path/to/file -dram 1 > /dev/null 2>&1" > /tmp/runmono
echo "gaya http://localhost:8883/start.cgi > /dev/null 2>&1" >> /tmp/runmono
/bin/busybox26 nohup sh /tmp/runmono > /dev/null 2>&1 &

Example

This final example will stop playback of any current file, start a video file and restart gaya after the file is done playing. During playback you can still send commands to the NMT for controlling playback.

echo 212 > /tmp/irkey
sleep 1
killall mono
killall pod
killall gaya
killall amp_test
sleep 1
echo "mono -nogui -single /path/to/file -dram 1 > /dev/null 2>&1" > /tmp/runmono
echo "gaya http://localhost:8883/start.cgi > /dev/null 2>&1" >> /tmp/runmono
/bin/busybox26 nohup sh /tmp/runmono > /dev/null 2>&1 &