/* Test script 2...trying to get feedback from module.
   MP3-TF-16P
  21/12/2022
  rcoded for software serial on UNO
  
*/
#include <SoftwareSerial.h>
 SoftwareSerial mySerial(2, 3);//RX/TX

//this function sends the actual command
//It receives the command byte and ParData is optional info such as track number or volume depending on the command
void sendDFCommand(byte Command, int ParData) {
  byte commandData[10]; //This holds all the command data to be sent
  byte q;
  int checkSum;
  Serial.print("Com: ");
  Serial.print(Command, HEX);
  //Each command value is being sent in Hexadecimal
  commandData[0] = 0x7E;//Start of new command
  commandData[1] = 0xFF;//Version information
  commandData[2] = 0x06;//Data length (not including parity) or the start and version
  commandData[3] = Command;//The command that was sent through
  commandData[4] = 0x01;//1 = feedback
  commandData[5] = highByte(ParData);//High byte of the data sent over
  commandData[6] = lowByte(ParData);//low byte of the data sent over
  checkSum = -(commandData[1] + commandData[2] + commandData[3] + commandData[4] + commandData[5] + commandData[6]);
  commandData[7] = highByte(checkSum);//High byte of the checkSum
  commandData[8] = lowByte(checkSum);//low byte of the checkSum
  commandData[9] = 0xEF;//End bit
  for (q = 0; q < 10; q++) {
   mySerial.write(commandData[q]);
  }
  Serial.println("Command Sent: ");
  for (q = 0; q < 10; q++) {
    Serial.println(commandData[q],HEX);
    
  }
  Serial.println("End Command: ");
  delay(100);
}

//play a specific track number
void playTrack(int tracknum){
  Serial.print("Track selected: ");
  Serial.println(tracknum);
  sendDFCommand(0x03, tracknum);
}

//plays the next track
void playNext(){
  Serial.println("Play Next");
  sendDFCommand(0x01, 0);
}

//volume increase by 1
void volumeUp() {
  Serial.println("Vol UP");
  sendDFCommand(0x04, 0);
}
//volume decrease by 1
void volumeDown() {
  Serial.println("Vol Down");
  sendDFCommand(0x05, 0);
}

//set volume to specific value
void changeVolume(int thevolume) {
  sendDFCommand(0x06, thevolume);
}


void setup() {
  Serial.begin(9600);
  Serial.println("DFPlayer Test Script 2");

  mySerial.begin(9600);
  mySerial.begin (9600);//start the softwareSerial to DF player
  
  delay(3500);//let everything initialise
  changeVolume(20);//set volume to 20....30 is very loud even on small speaker.
  delay(100);
  playTrack(4);
}

int q = 5;
byte returnCodes[10];
byte returnByteCounter;

void loop() {
  byte readByte;
while (mySerial.available()) {
  

    readByte = mySerial.read();
    Serial.print(readByte,HEX);
    Serial.print(" Count: ");
    Serial.println(returnByteCounter);
    
    if(returnByteCounter == 0){
      if(readByte == 0x7E){
        returnCodes[returnByteCounter] = readByte;
        returnByteCounter++;
      }
    }else{
        returnCodes[returnByteCounter] = readByte;
       returnByteCounter++; 
    }
    
    if(returnByteCounter > 9){
      Serial.println("Code String");
      for(int w = 0;w<10;w++){
        Serial.print(returnCodes[w],HEX);  
        Serial.print(" ");  
      }
      Serial.println(" ");
      if(returnCodes[3] == 0x3D){//track finished
         Serial.println("Play Next Track");
       playNext();//play next track 
      }
      returnByteCounter = 0;
    }



   
  }
 
  
}