If you only care about showing content as clearly as possible at the lowest cost, then you’ll want to turn to LCD or OLED technology. But a project’s display gives you an opportunity to get creative with the aesthetic, which opens up a whole world of different display types. If you want a retro feel, then you can inspiration in DIY GUY Chris’ gorgeous LED matrix.
This is a dot-matrix LED display with an overall resolution of 32×8. But that description alone doesn’t do the project justice. Chris used tiny 0603 SMD LEDs, which allowed for very high “pixel” density and that results in better clarity than a typical LED matrix display. To enable future expansion, Chris set this up as a host board that accepts four LED boards — each of which contains an 8×8 matrix. A MAX7219 IC drives the LEDs on each of those boards.
The LED boards connect to the host board through nifty mezzanine connectors. The host board contains an Arduino Nano that sends control signals to the MAX7219 chips. The Arduino can supply USB power to the LEDs, but there is also a DC jack for power when USB isn’t connected. Chris’ Arduino sketch lets the user “print” alphanumeric characters to scroll across the four LED matrices.
The best part about this design (other than the great style) is that Chris can scale it up in the future with larger host boards that accept more than four LED boards.
