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.

We’re surprised we haven’t seen this kind of clock before, or maybe we have, but forgot about it in the dark filing cabinets of our minds. The above picture of [danjhamer’s] Matrix Clock doesn’t quite do it justice, because this is a clock that doesn’t just tick away and idly update the minutes/hours.

Instead, a familiar Matrix-esque rain animation swoops in from above, exchanging old numbers for new. For the most part, the build is what you would expect: a 16×8 LED Matrix display driven by a TLC5920 LED driver, with an Arduino that uses a DS1307 RTC (real-time clock) with a coin cell battery to keep track of time when not powered through USB. [danjhamer] has also created a 3D-printed enclosure as well as added a piezo speaker to allow the clock to chime off customizable musical alarms.

You can find schematics and other details on his Hackaday.io project page, but first, swing down below the jump to see more of the clock’s simple but awesome animations.