If you’d like to integrate touch functionality to your LED matrix project, then tuenhidiy may have just the thing for you.
The setup uses 16 pairs of IR emitter and receivers arranged down the length of the bi-color 16×32 matrix to tell when one has inserted a finger or other object into an area. When sensed, it changes the corresponding column on the display from red to green or back again.
An Arduino Mega is used for overall control of the device, along with shift registers and multiplexers/demultiplexers to account for the massive amount of IO needed.
Code for the build is available on GitHub, and you can see it demonstrated in the video below.