EBC Exercise 12a 2.4 TFT LCD display via SPI
Embedded Linux Class by Mark A. Yoder
This is an exercise in interfacing the 2.4" TFT LCD display (ili9341) via a SPI bus.
The Hardware
Wire the LCD display as shown in the table.
LCD | Bone |
---|---|
MISO | P9_21 |
LED | P9_16 |
SCK | P9_22 |
MOSI | P9_18 |
D/C | P9_19 |
RESET | P9_20 |
CS | P9_17 |
GND | P9_2 |
VCC | P9_4 |
The Software
Clone the course repo.
bone$ git clone https://github.com/MarkAYoder/BeagleBoard-exercises.git exercises
and then
bone$ cd exercises/display/ili9341/fb bone$ git pull bone$ ./on.sh
After a moment the display should turn dark. Look in on.sh to see what it did.
Displaying Images
Follow the instructions in install.sh to download fbi and some images.
bone$ sudo apt install fbi
Display them with:
bone$ fbi -noverbose -T 1 -a boris.png
You should now see Boris the Beagle on your display.
Playing Movies
Install mplayer and load a movie on the Bone (see install.sh).
bone$ sudo apt install mplayer
Play the movie. Rotate the movie.
Generate Text
Install imagemagick.
bone$ sudo apt install imagemagick
See text.sh for an example of using imagemagick to write text to the LCD display. Write your name on the LCD. Display an image and write some text on it.
# Here's how to use imagemagick to display text # Make a blank image SIZE=320x240 TMP_FILE=/tmp/frame.png # From: http://www.imagemagick.org/Usage/text/ convert -background lightblue -fill blue -font Times-Roman -pointsize 24 \ -size $SIZE \ label:'ImageMagick\nExamples\nby Anthony' \ -draw "text 0,200 'Bottom of Display'" \ $TMP_FILE sudo fbi -noverbose -T 1 $TMP_FILE
Embedded Linux Class by Mark A. Yoder