Thank you. Really helpful. I got it working from using your example and another example (although) some tracks don't seem to play but the serial monitor shows that they have been selected, so I need to check the encoding of those). The code I used in the end was this:
#include <SoftwareSerial.h>
#define ARDUINO_RX 5//should connect to TX of the Serial MP3 Player module
#define ARDUINO_TX 6//connect to RX of the module
#define trigPin 13//for the distance module
#define echoPin 12
SoftwareSerial mySerial(ARDUINO_RX, ARDUINO_TX);//init the serial protocol, tell to myserial wich pins are TX and RX
////////////////////////////////////////////////////////////////////////////////////
//all the commands needed in the datasheet(http://geekmatic.in.ua/pdf/Catalex_MP3_board.pdf)
static int8_t Send_buf[8] = {0} ;//The MP3 player undestands orders in a 8 int string
//0X7E FF 06 command 00 00 00 EF;(if command =01 next song order)
#define NEXT_SONG 0X01
#define PREV_SONG 0X02
#define CMD_PLAY_W_INDEX 0X03 //DATA IS REQUIRED (number of song)
#define VOLUME_UP_ONE 0X04
#define VOLUME_DOWN_ONE 0X05
#define CMD_SET_VOLUME 0X06//DATA IS REQUIRED (number of volume from 0 up to 30(0x1E))
#define SET_DAC 0X17
#define CMD_PLAY_WITHVOLUME 0X22 //data is needed 0x7E 06 22 00 xx yy EF;(xx volume)(yy number of song)
#define CMD_SEL_DEV 0X09 //SELECT STORAGE DEVICE, DATA IS REQUIRED
#define DEV_TF 0X02 //HELLO,IM THE DATA REQUIRED
#define SLEEP_MODE_START 0X0A
#define SLEEP_MODE_WAKEUP 0X0B
#define CMD_RESET 0X0C//CHIP RESET
#define CMD_PLAY 0X0D //RESUME PLAYBACK
#define CMD_PAUSE 0X0E //PLAYBACK IS PAUSED
#define CMD_PLAY_WITHFOLDER 0X0F//DATA IS NEEDED, 0x7E 06 0F 00 01 02 EF;(play the song with the directory \01\002xxxxxx.mp3
#define STOP_PLAY 0X16
#define PLAY_FOLDER 0X17// data is needed 0x7E 06 17 00 01 XX EF;(play the 01 folder)(value xx we dont care)
#define SET_CYCLEPLAY 0X19//data is needed 00 start; 01 close
#define SET_DAC 0X17//data is needed 00 start DAC OUTPUT;01 DAC no output
////////////////////////////////////////////////////////////////////////////////////
void setup()
{
Serial.begin(9600);//Start our Serial coms for serial monitor in our pc
mySerial.begin(9600);//Start our Serial coms for THE MP3
delay(500);//Wait chip initialization is complete
sendCommand(CMD_SEL_DEV, DEV_TF);//select the TF card
delay(200);//wait for 200ms
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
}
void loop()
{
if(measureDistance(trigPin,echoPin)<10){
int randTrackNo;
randTrackNo = random(1, 9);
sendCommand(0x03,randTrackNo);
Serial.print("Playing track:");
Serial.println(randTrackNo);
delay(1000);//wait to avoid errors
}
delay(300);
}
void sendCommand(int8_t command, int16_t dat)
{
delay(20);
Send_buf[0] = 0x7e; //starting byte
Send_buf[1] = 0xff; //version
Send_buf[2] = 0x06; //the number of bytes of the command without starting byte and ending byte
Send_buf[3] = command; //
Send_buf[4] = 0x00;//0x00 = no feedback, 0x01 = feedback
Send_buf[5] = (int8_t)(dat >> 8);//datah
Send_buf[6] = (int8_t)(dat); //datal
Send_buf[7] = 0xef; //ending byte
for(uint8_t i=0; i<8; i++)//
{
mySerial.write(Send_buf*) ;//send bit to serial mp3*
Serial.print(Send_buf*,HEX);//send bit to serial monitor in pc*
}
Serial.println();
}
long measureDistance(int trigger,int echo){
* long duration, distance;*
* digitalWrite(trigger, LOW); //PULSE |---|
_ delayMicroseconds(2);_
_ digitalWrite(trigger, HIGH);_
_ delayMicroseconds(10);_
_ digitalWrite(trigger, LOW);*_
* duration = pulseIn(echo, HIGH);*
* distance = (duration/2) / 29.1;*
* Serial.println("distance:");*
* Serial.println(distance);*
* return distance;*
}
