Difference between revisions of "Template:S5Pxx18-SPI-2.8TFT"

Revision as of 06:43, 15 December 2017

1 Connect SPI 2.8"LCD to S5P4418/S5P6818 Based Board

The following steps only apply to Kernel Linux-4.4. We took the NanoPi Fire3 as an example. Run the following commands to initialize FriendlyElec's 2.8" SPI LCD.

These commands need to be run only once.

sudo mount /dev/mmcblk0p1 /boot
sudo apt-get update
sudo apt-get install device-tree-compiler
sudo fdtput /boot/s5p6818-nanopi3-rev05.dtb spi0/spidev@0 status -t s "disabled"
sudo fdtget /boot/s5p6818-nanopi3-rev05.dtb spi0/spidev@0 status
sudo fdtput /boot/s5p6818-nanopi3-rev05.dtb spi0/fbtft@0 status -t s "okay"
sudo fdtget /boot/s5p6818-nanopi3-rev05.dtb spi0/fbtft@0 status
sudo reboot

Note: the "s5p6818-nanopi3-rev05.dtb" file is the kernel dtb file for the NanoPi Fire3. For another board you need to check its system's "/sys/devices/platform/board/info" file to figure out its dtb file.:

cat /sys/devices/platform/board/info

Here is the info file's content for the NanoPi Fire3:
Hardware  : NANOPI3
Revision  : 0005
Serial  : fa6818dba7110739
The "Hardware" here is "NANOPI3", "Revision" is "0005", "CPU" is "S5P6818", therefore the NanoPi Fire3's kernel dtb file name is "s5p6818-nanopi3-rev05.dtb".

After the dtb file is confirmed you can reboot your board and run the following command to check if the fb_st7789v module is loaded:

lsmod

Here is what you expect to see:
Module Size Used by
fb_st7789v 3315 0
fbtft 31881 1 fb_st7789v

Or you can run dmesg to check that. In our case after we ran dmesg we found that the SPI LCD was recognized as an "fb1" device:

dmesg | grep fb_st7789v

Here is what you expect to see:
[ 6.728000] fb_st7789v: module is from the staging directory, the quality is unknown, you have been warned.
[ 6.908000] graphics fb1: fb_st7789v frame buffer, 320x240, 150 KiB video memory, 4 KiB buffer memory, fps=35, spi0.0 at 50 MHz
Now as long as you set your system's framebuffer device to fb1 in either Qt or X-Windows you will see output in your LCD.

1.1 Launch Lubuntu Desktop on 2.8"LCD

On lubuntu desktop run the following commands:
Firstly remove the armsoc configuration file:

sudo rm -f /usr/share/X11/xorg.conf.d/20-armsoc.conf

Secondly create a new configuration file /etc/X11/xorg.conf:

sudo vi /etc/X11/xorg.conf

Here is its content:

Section "Monitor"
    Identifier          "Primary"
    VendorName          "FriendlyARM"
EndSection
 
Section "Device"
    Identifier          "Primary"
    Driver              "fbdev"
    Option              "fbdev" "/dev/fb1"
EndSection

After reboot you will see the following GUI:

A touch panel is currently not supported yet. You need to use a mouse and keyboard to operate.

1.2 Run Qt Application on 2.8"LCD

Open a terminal in friendly-core and run the following commands to start a Qt demo:

. setqt5env
export QT_QPA_PLATFORM=linuxfb:fb=/dev/fb1
export QT_QPA_EGLFS_TSLIB=1
export QT_QPA_GENERIC_PLUGINS=tslib,evdevkeyboard
$QTDIR/examples/widgets/widgets/tetrix/tetrix

Here is a Qt demo:

A touch panel is currently not supported yet. You need to use a mouse and keyboard to operate.