Nick, thanks for the link, it DID clarify protocols. I have included code to I am running based on what I figured from the readings. My intent is to use the SPI library. From some examples, it appears the library takes care of the pin assignments. After playing around with the settings, I found one mode which changed the track, but it was more like a toggle between two tracks, not a sequence. So, if I am using the SPI functions correctly, I'm thinking the problem is either with the chip, which can be set for 4 different types of communication, or I am using the wrong serial protocol. I'm not able to find more documentation then states serial, but the diagram seems to illustrate a synchronous protocol, minus a latch. Let me know what you think, if you think the code checks out, I will make a trip back to the local Aplus distributor to double check how it was programmed.
#include <SPI.h>
//int clockPin = 13; //SCK
//int dataPin = 11; //MOSI
int ss = 10; //slave select
void setup() {
//pinMode(clockPin, OUTPUT);
//pinMode(dataPin, OUTPUT);
//pinMode(ss, OUTPUT);
digitalWrite(ss,LOW);
//SPI.setBitOrder(MSBFIRST);
//SPI.setClockDivider(SPI_CLOCK_DIV4); //default value = 4
SPI.setDataMode(SPI_MODE3);
/*
mode 0 >> CPOL = 0 & CPHA = 0 (plays song #1 loop)
mode 1 >> CPOL = 0 & CPHA = 1 (plays song #1 loop)
mode 2 >> CPOL = 1 & CPHA = 0 (plays song #2 loop)
mode 3 >> CPOL = 1 & CPHA = 1 (alternates between #2 and #3)
*/
SPI.begin();
}
void loop() {
for(int i=0; i<=5; i++){
delay(2000);
SPI.transfer(i);
delay(2000);