Difference between revisions of "How to do things with the beaglebone"
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echo "hello" > /dev/tty0 | echo "hello" > /dev/tty0 | ||
to output to your ssh session, try | to output to your ssh session, try | ||
| − | echo "hello | + | echo "hello" > /dev/tty</small> |
| + | |||
| + | These are serial output or char devices (as opposed to block which would be HDDs/flash (see a unix book)). | ||
| + | |||
| + | Access the char devices in /sys/dev/char | ||
| + | These will be the same devices as in /dev | ||
| + | but if you ls -l on /sys/dev/char you can get the path to the control / metadata of | ||
| + | a given device. Such as you would expect to see when flashing a LED on/off via sys/fs. | ||
| + | ref: https://elinux.org/EBC_Exercise_17_Switching_a_GPIO_to_an_LED#Setup and | ||
| + | https://elinux.org/EBC_Exercise_17_Switching_a_GPIO_to_an_LED#Checking_.2Fsys.2Fclass.2Fleds | ||
| + | |||
| + | Going to /sys/dev/char is intuitive, and more so than /sys/class/whatever. But /sys/class has things | ||
| + | that dev does not have, so you must remember /sys/dev/char and /sys/class for starters. This will get | ||
| + | you access to hw control, afaik. | ||
| + | |||
====Output Video to TFT==== | ====Output Video to TFT==== | ||
<small>Download video from somewhere. | <small>Download video from somewhere. | ||
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root@beaglebone:/sys/class/graphics# ls | root@beaglebone:/sys/class/graphics# ls | ||
fb0 fbcon | fb0 fbcon | ||
| + | ref: https://unix.stackexchange.com/questions/342815/how-to-send-ffmpeg-output-to-framebuffer | ||
</small> | </small> | ||
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| + | {{Electronics}} | ||
Latest revision as of 04:23, 24 November 2022
Pocket Beagle
Output Text to TFT
This assumes you have the game boy tft shield. Although others that are supported and detected will likely work similarly.
echo "hello" > /dev/tty0
to output to your ssh session, try
echo "hello" > /dev/tty
These are serial output or char devices (as opposed to block which would be HDDs/flash (see a unix book)).
Access the char devices in /sys/dev/char These will be the same devices as in /dev but if you ls -l on /sys/dev/char you can get the path to the control / metadata of a given device. Such as you would expect to see when flashing a LED on/off via sys/fs. ref: https://elinux.org/EBC_Exercise_17_Switching_a_GPIO_to_an_LED#Setup and https://elinux.org/EBC_Exercise_17_Switching_a_GPIO_to_an_LED#Checking_.2Fsys.2Fclass.2Fleds
Going to /sys/dev/char is intuitive, and more so than /sys/class/whatever. But /sys/class has things that dev does not have, so you must remember /sys/dev/char and /sys/class for starters. This will get you access to hw control, afaik.
Output Video to TFT
Download video from somewhere. Resize/scale to small enough resolution (NOTE: this resolution is 128x96, from book Ffmpeg Basics by Korbel)
ffmpeg -i video.mp4 -s sqcif outputsmall.mp4 mplayer -loop 0 -vo fbdev2 outputsmall.mp4
Video should output direct on /dev/tty0
Framebuffer settings:
cd /sys find . -print | grep fb0
There should be an fb0 (graphics) and fbcon (text console) e.g.
root@beaglebone:/sys/class/graphics# ls fb0 fbcon
ref: https://unix.stackexchange.com/questions/342815/how-to-send-ffmpeg-output-to-framebuffer
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