Using the Tingbot screen in recent Raspberry Pi OS versions

[vitorio]

I recently got the Tingbot screen running under the latest (as of January 2023) Raspberry Pi OS (Bullseye, released 2022-09-22), stock, without rolling back the kernel.

Change the line in /boot/config.txt from:

dtoverlay=tingbot:xohms=80

to:

dtoverlay=fbtft
dtparam=spi0-0,ssd1289
dtparam=speed=48000000,regwidth=0
dtparam=reset_pin=22,dc_pin=27,led_pin=18
dtparam=rotate=270,bgr,fps=50

dtoverlay=ads7846
dtparam=penirq=25,xohms=80,swapxy=1

This uses the new, built-in FBTFT overlays, and the existing touchscreen overlay. This may mean that newer Raspberry Pi 3B+ or Raspberry Pi 4 models may work with the Tingbot hardware, but I haven't tried them. This worked with both 32-bit and 64-bit versions.

I didn't appear to need the fbcon=map:10 addition to /boot/cmdline.txt to get the console to appear on the display.

If you're running X11 on the Tingbot display, this calibration file (generated via xcalibrate) works for me (place it in /usr/share/X11/xorg.conf.d/99-libinput-ts-calib.conf):

Section "InputClass"
    Identifier      "calibration"
    MatchProduct    "ADS7846 Touchscreen"
    Option          "CalibrationMatrix"  "-1.139887904380033 0.0 1.103406570595112 0.0 -1.115188775130766 1.0674508540122458 0.0 0.0 1.0"
EndSection