How to Create a Dot Matrix Pattern in Photoshop. From slap bracelets to neon clothes, fashion trends from the 1980s have bounced back in a big way, so if you're looking to merge 1980s technology ...

That all changed when he discovered a cheap source of illuminated pushbuttons on Aliexpress, leading to this DIY 4×4 illuminated button matrix design which communicates over I 2 C.