How to use OSOYOO 3.5HDMI resistive touchscreen with Bookworm＆Trixie(Version 2025-10-01 and earlier)

1) Install the Bookworm/Trixie image as the official website or follow our tutorial.

2) After the image has finished writing, open the config.txt file in the root directory of the TF card, add the following code at the end of config.txt, then save and quit the TF card safely.

dtoverlay=bw-ads7846,penirq=25,xmin=200,xmax=3900,ymin=200,ymax=3900,speed=50000

3) Download the bw-ads7846.dtbo file. Copy this file to the overlays directory (/boot/overlays/).

4) Quit the TF card safely.

5) Insert the TF card into the Raspberry Pi, power on the Raspberry Pi, and wait for more than 10 seconds to display normally. But the touch is abnormal at that time, and the touch needs to be calibrated as the following steps.

Note: Recommend to remotely control Raspberry Pi via SSH, VNC or other remote desktop tools, as the resolution is too high as default. (Here we use PuTTY for Windows users. You can learn more about remotely control Raspberry Pi from: https://osoyoo.com/?p=56660)

Step 1) Set to use X11 instead of Wayland

1. Run the following command firstly:

sudo raspi-config

2. Then select Advanced Options, then Wayland which now controls which backend to use for the desktop, then X11. Save your settings and reboot the Raspberry Pi. In Bookworm it now defaults to Wayland on the PI4 & PI5, so we need to switch it to W1 X11.

Step 2) Change the Screen Configuration

Use a mouse to control your screen, then click the Raspberry Pi icon → Preferences → Screen Configuration, in the new window, click layout → screen → HDMI → resolution → 640×480, then click Apply, and click OK in the new pop. We recommend setting the resolution to 640×480.

Step 3) Install XPT2046 Driver and Calibrator

Install xpt2046 driver and calibrator by typing the following commands:

sudo apt install xserver-xorg-input-evdev

sudo apt install -y xinput-calibrator

Step 4) Config Touch Calibration Files

1. Run the following commands:

sudo cp -rf /usr/share/X11/xorg.conf.d/10-evdev.conf /usr/share/X11/xorg.conf.d/45-evdev.conf

sudo nano /usr/share/X11/xorg.conf.d/99-calibration.conf

2. Add the following parameters in 99-calibration.conf:

Section "InputClass"
Identifier "calibration"
MatchProduct "ADS7846 Touchscreen"
Option "Calibration" "211 3942 3905 141"
Option  "SwapAxes"  "1"
EndSection

3. Press Ctrl + X then Y, then Enter to save this file, then run the following command to reboot your Raspberry Pi:

sudo reboot

Step 5) Calibrate Touch

a. Use mouse to control your screen, then click [Preferences] → [Calibrate Touchscreen] from main menu, (or enter DISPLAY=:0.0 xinput_calibrator in the terminal), click four crossbar points on corners, it will show the calibration values which are similar to previously written to the 99-calibration.conf file.

b. After calibration (click four cross bar points on corners), it will show the calibration values which are similar to previously written to the 99-calibration.conf file.

c. Edit 99-calibration.conf file again by typing the following command:

sudo nano /usr/share/X11/xorg.conf.d/99-calibration.conf

d. Replace the following lines with new values shown in the calibration result (from step b). Check touch, repeat calibration if it is not correct.

Option  "Calibration" "211 3942 3905 141"
Option  "SwapAxes" "1"