Just a hobbyist intermediate level Tom. Good knowledge with coding but not much with complex wiring /schema.
Worked with Arduino projects such as basic robots, home automation and recently working on a drone.
Standard leds have a negative and positive terminal, each row /column would have 8 leds each. I presume all the negatives for all 8 leds on each row have to be wire soldered/joined together and then connected to pin on max7219?
Likewise with the positive pins?