I try to drive a LED display with MAX7219 and Arduino. I use LTC-2727G common cathode 7-segment/4-digit display, which is previously successfully multiplexed with Arduino. But this time i need more free pins, and i selected MAX7219 for driving the display.
The problem is, that if i run the MAX7219 7-segment example from LedControl library, all digits show "8", all segments light up, and nothing happens.
I can see that the MAX is writing characters to the first digit (but only there), because the first digit lights up sometimes brighter as the others.
What can cause this? I tried different values for Rset, but nohing changed.
My first thought was a shortage, but for all the 4 digits? Noooo
MAX7219 is brand new... Communication is OK...
Has anybody seen anything like that? Any help would be appreciated...