In Arduino, int is a sixteen bit type. In writeLED() you're only shifting out twenty bits rather than the thirty six bits that the display controller is expecting. To shift out all thirty six bits, you would need to make i an unsigned long.
In Arduino, int is a sixteen bit type. In writeLED() you're only shifting out twenty bits rather than the thirty six bits that the display controller is expecting. To shift out all thirty six bits, you would need to make i an unsigned long.