Can I ask a question?
I want to make an m5stack program that would play an mp3 file if I send a trigger via UDP, and would stop if I send a different trigger via UDP.
I followed some code from:
http://forum.m5stack.com/topic/143/lesson-6-1-speaker-mp3-player/9

But when I sent the trigger, the mp3 only played the first second (1s) and kept repeating the same time position. It wouldn't play the entire mp3 song.

This is the code that I used:

#include <M5Stack.h>
#include <WiFi.h>
#include <WiFiUdp.h>
#include "AudioFileSourceSD.h"
#include "AudioFileSourceID3.h"
#include "AudioGeneratorMP3.h"
#include "AudioOutputI2S.h"
#define N 1024

bool playing = true;
AudioGeneratorMP3 *mp3;
AudioFileSourceSD *file;
AudioOutputI2S *out;
AudioFileSourceID3 *id3;

const char* ssid = "wifiname";
const char* password = "wifipassword";
const int port = 5555;

// The udp library class
WiFiUDP udp;

void print_wifi_state(){
M5.Lcd.clear(BLACK); // clear LCD
M5.Lcd.setTextColor(YELLOW);
M5.Lcd.setCursor(3, 3);
M5.Lcd.println("");
M5.Lcd.println("WiFi connected.");
M5.Lcd.print("IP address: ");
M5.Lcd.println(WiFi.localIP());
M5.Lcd.print("Port: ");
M5.Lcd.println(port);
}

void setup_wifi(){
M5.Lcd.setTextColor(RED);
M5.Lcd.setTextSize(2);
M5.Lcd.setCursor(3, 10);
M5.Lcd.print("Connecting to ");
M5.Lcd.println(ssid);

// setup wifi
WiFi.mode(WIFI_STA); // WIFI_AP, WIFI_STA, WIFI_AP_STA or WIFI_OFF
WiFi.begin(ssid, password);
// WiFi.begin();

// Connecting ..
while (WiFi.status() != WL_CONNECTED) {
delay(100);
M5.Lcd.print(".");
}

// print state
print_wifi_state();

udp.begin(port);

}

void setup() {
M5.begin();
M5.Speaker.setVolume(5);
play('m');
// setup wifi
setup_wifi();

}

bool play(char dir){
switch(dir)
{
case 'm':
delete file;
delete out;
delete mp3;
mp3 = NULL;
file = NULL;
out = NULL;
file = new AudioFileSourceSD("/");
id3 = new AudioFileSourceID3(file);
out = new AudioOutputI2S(0, 1);
out->SetOutputModeMono(true);
mp3 = new AudioGeneratorMP3();
mp3->begin(id3, out);
playing = false;
return true;
default:
if(playing){
play('m');
return true;
}
break;
}
mp3->stop();
delete file;
delete out;
delete mp3;
mp3 = NULL;
file = NULL;
out = NULL;
file = new AudioFileSourceSD("/RainDrizzle.mp3");
id3 = new AudioFileSourceID3(file);
id3->seek(trackList->timePos, 1);
out = new AudioOutputI2S(0, 1);
out->SetOutputModeMono(true);
mp3 = new AudioGeneratorMP3();
mp3->begin(id3, out);
playing = true;

return true;
}

void loop() {
char packetBuffer[N];
int packetSize = udp.parsePacket();

// get packet
if (packetSize){

int len = udp.read(packetBuffer, packetSize);

if (len > 0){
  packetBuffer[len] = '\0'; // end
}

}

if(strcmp(packetBuffer,"start")==0){
// print param
M5.Lcd.clear(BLACK);
M5.Lcd.setCursor(3, 3);
M5.Lcd.setTextColor(GREEN);
M5.Lcd.println(packetBuffer);

play('t');

}

if(strcmp(packetBuffer,"stop")==0){
M5.Lcd.clear(BLACK);
M5.Lcd.setCursor(3, 3);
M5.Lcd.setTextColor(GREEN);
M5.Lcd.println(packetBuffer);
play('m');
}

if(playing){
  if(mp3->isRunning()){
    if(!mp3->loop()){
      mp3->stop();
      playing = false;
    }
  }
  else{
    delay(1000);
  }

}
M5.update();
}

Please advise if anything's wrong in the code.

Thank you in advance.