Velleman KA02 not working on Mega 2560 r3
Nevermind, I solved it. There's 6 pins located on the Uno and Mega labelled ICSP, and those were the key. I simply connected the MOSI, MISO and SCK pins on the Mega to the audio shield (along with GND and 5V) and also the 10 pin (audio shield) to the 53 pin (Mega) via a male to male jumper. The header code was modified to work with the new values, and now I am able to send character signals via the serial monitor.