Variable Message sign controller

Hello, i'm Vladimir espinoza, i'm a mechanical engineer from El Salvador, I love learn about electronics, sensors and programming microcontrollers, a month a go I receive a task to fix a LED variable Message sign that does not work, so I did reverse engineering to a one LED panel to build the schematic and figure out how it works, so a grab my Arduino UNO andas I wrote a sketch to test the panel, when I make it work I started to write the data bits to form the letters for each panel then I start to chose the components and build the schematic to end with the PCB layout design on EasyEda then I ordered 5 PCB to JLCPCB, i have to wait about two weeks for the arrival of the PCB and the components so I started to assembly the circuit, it took me around a half of a day to solder it because I only useda a quicko soldering iron, leaded tin and a lot of flux, the next day I uploaded the sketch to the board and tested on the equipment and it did work,I ended by changing some wires for power, I checked the photovoltaic panel to ensure it generates electricity and I added a solar charge controller and a battery.