void midiSend(int control, int message)
{
String hexMessage = String(message, HEX); // convert int value into hex value for midi
Serial.write(OPCODE); // defined in this sketch to CC message
Serial.write(control); // code for the control to be changed
Serial.print(hexMessage); // code for the new value to send
}
I don't understand this. You shouldn't be sending a string of characters for midi. You don't convert control to a String, so why do it with message? Just Serial.write(message).