Waveshare screen config - Madhu N

waveshare35a.txt

1. use this /boot/cmdline.txt:

dwc_otg.lpm_enable=0 console=tty1 console=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo

2. edit the end of /boot/config.txt to contain:

dtparam=audio=on
dtparam=spi=on
dtoverlay=ads7846,penirq=25,penirq_pull=2,xohms=150,swapxy=1,xmin=300,ymin=700,xmax=3800,ymax=3400,pmax=255
dtoverlay=waveshare35a

3. copy waveshare35a.dtb to the /boot/overlays directory as:

waveshare35a.dtbo

(note that the new kernel requires a '.dtbo' on overlays now!)

4. edit /usr/share/X11/xorg.conf.d/99-fbturbo.conf to contain:

Section "Device"
Identifier "Allwinner A10/A13 FBDEV"
Driver "fbturbo"
Option "fbdev" "/dev/fb1"

Option "SwapbuffersWait" "true"
EndSection

5. create a file named 99-calibration.conf under /etc/X11/xorg.conf.d to contain:

Section "InputClass"
Identifier "calibration"
MatchProduct "ADS7846 Touchscreen"
Option "Calibration" "3932 300 294 3801"
Option "SwapAxes" "1"
EndSection

6. reboot and enjoy!