Just throwing this out there in case I get lucky. Purchased a P10 32x16 PMD to use with my Mega but can't seem to get the software or hardware figured out, not sure which.
I'm basically adapting this guide for the Uno to the Mega: LED Display Board using P10 LED Matrix Display and Arduino
Based on several threads, I've modified the DMD.h file to change to pins 51 and 52, as I understand this has something to do with the Mega using different pins for the SPI feature:
#define PIN_DMD_CLK 52
#define PIN_DMD_R_DATA 51
I am maybe also supposed to change #define PIN_OTHER_SPI_nCS from 10 to 1, i.e. #define PIN_OTHER_SPI_nCS 1, per this thread? Arduino mega using dmd library (SOLVED) -Freetronics Forum
To give the matrix power, I first tried connecting 3 AA batteries in series to achieve 4.5 volts. Since it wasn't working, I tried switching the power to the Mega's 5V connection, since I read that the lights should still work but would just be dim.
Nothing seems to be working, though. I'm not sure if I've just wired something wrong, but my guess is that it's a software problem. Any thoughts?