18 December 2018 at 12:37 pm
Back in April I designed two boards just for fun. One was a Persistence Of Vision (POV) board and the other was an educational board for my students to understand how a Matrix display works.
I got the black PCB’s quite quickly from PCBWay and got them soldered up. It all worked out as expected and I was able to use it with my students this autumn. It really worked out well. Rather than wondering how it worked, I told the students to come up to me after calss so they could play around with it. The result was much less confusion around how a Matrix works and it looks gorgeous with it’s 8x8 matrix of 10mm LEDs.
The Matrix has switches along the edge that pull each row High or Low. By playing with the switches, the students build an intuitive understanding of how the matrix works and why you never can turn on more than one row at a time. The switched also has a middle position where an onboard ATMEGA328P-AU will control the lines to display a scrolling text. The micro also has a potmeter connected to one of the analog inputs so you can decrease the scroll speed all the way down so you can see single lines lighting up. Since it’s always nice to have - I added a button and a LED to it also that can be used for any purpose. The only thing I didn’t think through was adding either a regulator so that it could be battery powered or a USB power input. Will add that if I do another revision. Very happy with how this project turned out - both electronically and for teaching!