This guide walks through the basic usage of an OLDI display used in conjunction with the phyCORE-AM57x development kit.
|Item||Item Number (Description)||Link|
7" LVDS Capacitive Touch Display
Setting up the Display
There is a switch labeled "S1" on the back of LCD-018 where the backlight can be set to either: "always on", "always off", "PWM", or "potentiometer" (there is a point on the display with reference designator R30). In order to control the backlight via the phyCORE-AM57x as described in this guide, the boot switch needs to be set to PWM. (1,2,4 OFF; 3 ON)
- With the kit powered off and the power supply removed, connect the display to connector X25 on the phyCORE-AM57x Carrier Board as shown in the picture below.
- Power on the board and boot into Linux.
- An application called the Matrix-GUI will appear on the display.
Controlling the Backlight
The backlight brightness of the display is controlled by a PWM and can be configured via Linux in the sysfs.
To read the current backlight brightness:
Set "brightness" to values 0-7, with 7 being the brightest. For example:
echo 7 > /sys/devices/platform/backlight/backlight/backlight/brightnessCODE
Set bl_power to turn backlight off/on. Valid values are 1 for off and 0 for on:
echo 1 > /sys/devices/platform/backlight/backlight/backlight/bl_power echo 0 > /sys/devices/platform/backlight/backlight/backlight/bl_powerCODE
Calibrating the Touch Controller
If you find that your touches on the display are not registering correctly then it is likely you need to re-calibrate the touch controller. See the below steps for instructions on how to do this!
Enter the following command:
- On the display you should see a white background with a red X somewhere on the screen. Tap the red X's as they appear until complete.
The phyCORE-AM57x Linux BSP comes equipped with video encoding/decoding capabilities using GStreamer Pipelines and also includes sample files for exploring these capabilities.
In order to validate your kit's video encoding capabilities, first stop all graphics processes:
/etc/init.d/matrix-gui-2.0 stop /etc/init.d/weston stopCODE
You should now see a black screen that displays the text "Please wait..."
Execute the following command to encode a raw video into MPEG format:
gst-launch-1.0 filesrc location=/usr/share/ti/video/airshow_p352x288.yuv ! videoparse width=352 height=288 format=nv12 ! video/x-raw, width=352, height=288 ! ducatimpeg4enc ! filesink location=/home/root/airshow_p352x288.mp4CODE
Now decode the MPEG video that was just generated:
You should see a short clip play on the display.
Other encoder/decoder demos are also available:
H.265 (HEVC) Decode
gst-launch-1.0 filesrc location=/usr/share/ti/video/TearOfSteel-Short-1280x720.265 ! 'video/x-raw, format=(string)NV12, framerate=(fraction)24/1, width=(int)1280, height=(int)720' ! h265dec threads=2 ! vpe ! kmssink
H.264 (IVAHD) Encode
gst-launch-1.0 filesrc location=/usr/share/ti/video/airshow_p352x288.yuv ! videoparse width=352 height=288 format=nv12 ! video/x-raw, width=352, height=288 ! ducatih264enc ! filesink location=/home/root/airshow-352-288-nv12-inp_gst.h264
H.264 (IVAHD) Decode
gst-launch-1.0 filesrc location=/home/root/airshow-352-288-nv12-inp_gst.h264 ! queue ! h264parse ! ducatih264dec ! kmssink