MaaXBoard-Linux-Debian-UM-V1.2
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3.4.3 LVDS Screen
Choose LVDS screen, the fdt_file value should be:
fdt_file=em-sbc-imx8m-dcss-lvds.dtb
LVDS supports backlight brightness adjustment. The backlight brightness has a range from 0 to 10, in
which 10 means highest brightness, 0 means lowest.
Execute the following instructions on the serial terminal to implement the backlight test:
root@maaxboard:~# echo 5 > /sys/class/backlight/lvds_backlight/brightness
3.5 Touchscreen
The MIPI-DSI and LVDS screen support touch screen, users could touch the screen to control the
Debian Weston Desktop Environment.
3.6 Audio
3.6.1 HDMI Audio
Choose HDMI screen as displayer, connect HDMI displayer and the Audio devices, play the audio file:
root@maaxboard:~# aplay audio_sample.wav
root@maaxboard:~# gst-play-1.0 audio_sample.wav
Note:
aplay
command support audio file in wav format,
gst-play
command support wav, mp3 and aac
format.
3.6.2 USB Audio Device
MaaXBoard could support USB audio device (which do not need specified driver) to play audio. When
using MIPI-DSI or LVDS screens, you can play audio from USB audio device.
root@maaxboard:~# aplay audio_sample.wav
root@maaxboard:~# gst-play-1.0 audio_sample.wav
If other audio device, such as HDMI Audio, is connected, use
aplay
command to check the card id, then
specify the device when play the audio file.
root@maaxboard:~# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: imxaudiohdmi [imx-audio-hdmi], device 0: imx8 hdmi i2s-hifi-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio]
Subdevices: 1/1
