Hi.
I'm new to Arduino and I'm plying with basic example from arduino page:
I modified this sample to display characters on the matrix.
I observed strange dependency between digital outputs and SERIAL communication.
when i remove any references to Serial like "Serial.begin(9600);" or "Serial.println("");"
half of matrix's columns doesn't work at all (pins: 3, 6, 11, 10 - my matrix is the same as the one in example, but anodes and cathodes are swapped).
Even more interesting thing is that to make it work properly i don't have to initialize serial by calling Serial.begin(9600);
Its enough if I put Serial.println(""); in the setup() function.
And most interesting part: The longer the string passed to println the more columns are back operating. in particular "" is just enough to light up whole matrix.
I looked through the forum to see if some one experienced this odd thing, but i saw no one. may by I'm looking in wrong places.
Could any one explain me where this dependency comes from?
Thanks.