Sure thing! Here’s a revised version of your forum post that focuses purely on the touchscreen calibration issue without mentioning the SSH or DISPLAY=:0 complications:
⸻
Title: Help with Calibrating Dual Touchscreens on Raspberry Pi in Extended Display Mode
Post:
Hi everyone,
I’m working on a project with a Raspberry Pi 4 connected to two identical 1080p touchscreen monitors, configured in extended desktop mode. The displays work fine, but I’m having trouble getting the touch input calibrated correctly so that each screen registers touch events within its own display area.
Here’s what I’ve done so far:
1.I used xinput list to identify both touchscreens and confirm they’re recognized individually.
2.I’ve been using the xinput set-prop command with the Coordinate Transformation Matrix to try mapping the touch input for each screen.
3.For each screen, I’m adjusting the scaling and translation values in the matrix:
• For the left screen, I’m using a matrix like 0.5 0 0 0 1 0 0 0 1
• For the right screen, I’ve tried 0.5 0 0.5 0 1 0 0 0 1 to shift it over, and it works on the left screen—but the mouse is not positioning correctly on the right screen.
The issue I’m running into is that calibration isn’t quite consistent, and it seems like adjusting one screen affects the behavior of the other. I’m wondering:
• Is there a more precise way to determine the correct values for each screen?
• Are there any tools or utilities that can assist with touchscreen calibration in multi-monitor setups?
• Are there any best practices for applying these settings permanently (e.g., at boot time)?
Any help or insights would be much appreciated!
Thanks in advance!
- Jason O
⸻
Title: Help with Calibrating Dual Touchscreens on Raspberry Pi in Extended Display Mode
Post:
Hi everyone,
I’m working on a project with a Raspberry Pi 4 connected to two identical 1080p touchscreen monitors, configured in extended desktop mode. The displays work fine, but I’m having trouble getting the touch input calibrated correctly so that each screen registers touch events within its own display area.
Here’s what I’ve done so far:
1.I used xinput list to identify both touchscreens and confirm they’re recognized individually.
2.I’ve been using the xinput set-prop command with the Coordinate Transformation Matrix to try mapping the touch input for each screen.
3.For each screen, I’m adjusting the scaling and translation values in the matrix:
• For the left screen, I’m using a matrix like 0.5 0 0 0 1 0 0 0 1
• For the right screen, I’ve tried 0.5 0 0.5 0 1 0 0 0 1 to shift it over, and it works on the left screen—but the mouse is not positioning correctly on the right screen.
The issue I’m running into is that calibration isn’t quite consistent, and it seems like adjusting one screen affects the behavior of the other. I’m wondering:
• Is there a more precise way to determine the correct values for each screen?
• Are there any tools or utilities that can assist with touchscreen calibration in multi-monitor setups?
• Are there any best practices for applying these settings permanently (e.g., at boot time)?
Any help or insights would be much appreciated!
Thanks in advance!
- Jason O
Statistics: Posted by Jdo300 — Fri Jul 04, 2025 11:36 am