I was about to order some MAX7219 that are to be used with common-cathode led displays and I suspect the led matrix I have is common-anode (I have to find it and check). So that got me worried, but then I thought what if I interchange the rows and columns pins? will it not be the same?
If the led display is of the 7-segment type, then this obviously cannot work. But in the led matrix case all leds are 'equal'. For example suppose we have a 4x4 matrix and we want to turn on only the top leftmost led, then the pin voltages will be like this:
columns columns
common cathode common anode
H L L L L H H H
L H
rows H L
H L
H L
so if we interchange the rows pins with the columns pins, a common-cathode matrix becomes common-anode and vice-versa, is this right?
and if it is, doesn't it mean that the MAX7219 can work with a common-anode led matrix just as well?