Raspberry Pi 3 B+ 3.5inch LCD problems Fix

Back up the config file before trying.

Issue 1

Just showing white screen.

Solution

1. cd LCD-show sudo ./LCD35-show
2. raspi-config > advanced > Wayland > select X11
3. sudo nano /boot/firmware/config.txt
   Add
   dtoverlay=piscreen,drm
   at the end of lines.
4. reboot

Issue 2

Touch screen XY works as inverted.

Solution

1. cd /usr/share/X11/xorg.conf.d/
2. Open and edit 99-calibration.conf or something similar.
3. Add
   Option "TransformationMatrix" "-1 0 1 0 -1 1 0 0 1"
   at Section.
4. Reboot

90° = "0 -1 1 1 0 0 0 0 1"
180° = "-1 0 1 0 -1 1 0 0 1"
270° = "0 1 0 -1 0 1 0 0 1"

/boot/firmware/config.txt

On working condition with LCD35-show

hdmi_force_hotplug=1

dtparam=i2c_arm=on

dtparam=spi=on
enable_uart=1

dtparam=audio=on
dtoverlay=waveshare35a

hdmi_force_hotplug=1

hdmi_group=2
hdmi_mode=1
hdmi_mode=87
hdmi_cvt 480 320 60 6 0 0 0
hdmi_drive=2
dtoverlay=piscreen,drm

On working condition with LCD-hdmi(Goes wrong in my case just dtparam=audio=on remaining)

hdmi_force_hotplug=1
dtparam=audio=on
camera_auto_detect=1
display_auto_detect=1
auto_initramfs=1
dtoverlay=vc4-kms-v3d
max_framebuffers=2
disable_fw_kms_setup=1
disable_overscan=1
arm_boost=1
[cm4]
otg_mode=1
[all]

Manually pasted it into the config.txt every sudo ./LCD-hdmi
And add dtoverlay=piscreen,drm again if want to sudo ./LCDxx-show(add after sudo ./LCDxx-show)

Comment

使用品はKuman 3.5inch touch screen と3 B+
Raspberry Pi OS 32-bit 2024-03-15