diff --git a/audioooo/src/main.cpp b/audioooo/src/main.cpp
index 358f491..2d9570d 100644
--- a/audioooo/src/main.cpp
+++ b/audioooo/src/main.cpp
@@ -16,7 +16,7 @@
 //============<identities>============
 //
 #define MY_GROUP_ID         (10000)
-#define MY_ID               (MY_GROUP_ID + 7)
+#define MY_ID               (MY_GROUP_ID + 2)
 #define MY_SIGN             ("AUDIOOOO")
 #define ADDRESSBOOK_TITLE   ("broadcast only")
 //
@@ -135,44 +135,44 @@ String screen_filename = "/___.mp3";
 extern Task screen_cmd_notify_task;
 bool cmd_notify = false;
 void screen_cmd_notify() {
-  if (screen_cmd_notify_task.isFirstIteration()) cmd_notify = true;
-  else if (screen_cmd_notify_task.isLastIteration()) cmd_notify = false;
-  else cmd_notify = !cmd_notify;
+    if (screen_cmd_notify_task.isFirstIteration()) cmd_notify = true;
+    else if (screen_cmd_notify_task.isLastIteration()) cmd_notify = false;
+    else cmd_notify = !cmd_notify;
 }
 Task screen_cmd_notify_task(500, 10, &screen_cmd_notify, &runner, false);
 
 //
 extern Task screen_task;
 void screen() {
-  //clear screen + a
-  int line_step = 12;
-  int line = 0;
-  display.clearDisplay();
-  display.setTextColor(SSD1306_WHITE);
-  display.setTextSize(1);
+    //clear screen + a
+    int line_step = 12;
+    int line = 0;
+    display.clearDisplay();
+    display.setTextColor(SSD1306_WHITE);
+    display.setTextSize(1);
 
-  //line1 - mode line (playing / stopped) + notify mark
-  display.setCursor(0, line);
-  if (audio.isRunning()) display.println("= playing ===");
-  else display.println("* stopped !:.");
-  if (cmd_notify) {
-    display.setCursor(120, line);
-    display.println("*");
-  }
-  line += line_step;
+    //line1 - mode line (playing / stopped) + notify mark
+    display.setCursor(0, line);
+    if (audio.isRunning()) display.println("= playing ===");
+    else display.println("* stopped !:.");
+    if (cmd_notify) {
+        display.setCursor(120, line);
+        display.println("*");
+    }
+    line += line_step;
 
-  //line2 - filename
-  display.setCursor(0, line);
-  display.println(screen_filename.c_str());
-  line += line_step;
+    //line2 - filename
+    display.setCursor(0, line);
+    display.println(screen_filename.c_str());
+    line += line_step;
 
-  //line3 - rf. last msg.
-  display.setCursor(0, line);
-  display.println(screen_cmd.c_str());
-  line += line_step;
-  //
-  display.display();
-  //
+    //line3 - rf. last msg.
+    display.setCursor(0, line);
+    display.println(screen_cmd.c_str());
+    line += line_step;
+    //
+    display.display();
+    //
 }
 Task screen_task(SCREEN_PERIOD, TASK_FOREVER, &screen, &runner, true);
 
@@ -182,93 +182,104 @@ int sample_now = 0; //0~999
 //on 'start'
 void sample_player_start()
 {
-  //filename buffer - 8.3 naming convension! 8+1+3+1 = 13
-  // + '/' root symbol 13+1 = 14 (ESP32 specific?)
-  char filename[14] = "/NNN.mp3";
-  //search for the sound file
-  int note = sample_now;
-  int nnn = (note % 1000);  // 0~999
-  int nn =  (note % 100);   // 0~99
-  filename[1] = '0' + (nnn / 100); // N__.MP3
-  filename[2] = '0' + (nn / 10);   // _N_.MP3
-  filename[3] = '0' + (nn % 10);   // __N.MP3
-  //TEST
-  Serial.println(filename);
-  screen_filename = String(filename);
-  bool test = SD.exists(filename);
-  if (!test) {
-    Serial.println("... does not exist.");
-    screen_filename = screen_filename + "_!NEXIST!";
-    return;
-  }
-  //start the player!
-  audio.connecttoSD(filename);
-  delay(10);
+    //filename buffer - 8.3 naming convension! 8+1+3+1 = 13
+    // + '/' root symbol 13+1 = 14 (ESP32 specific?)
+    char filename[14] = "/NNN.mp3";
+    //search for the sound file
+    int note = sample_now;
+    int nnn = (note % 1000); // 0~999
+    int nn =  (note % 100); // 0~99
+    filename[1] = '0' + (nnn / 100); // N__.MP3
+    filename[2] = '0' + (nn / 10); // _N_.MP3
+    filename[3] = '0' + (nn % 10); // __N.MP3
+    //TEST
+    Serial.println(filename);
+    screen_filename = String(filename);
+    bool test = SD.exists(filename);
+    if (!test) {
+        Serial.println("... does not exist.");
+        screen_filename = screen_filename + "_!NEXIST!";
+        return;
+    }
+    //start the player!
+    audio.connecttoSD(filename);
+    delay(10);
 }
 Task sample_player_start_task(0, TASK_ONCE, &sample_player_start, &runner, false);
 
 //on 'stop'
 void sample_player_stop() {
-  //filename buffer - 8.3 naming convension! 8+1+3+1 = 13
-  // + '/' root symbol 13+1 = 14 (ESP32 specific?)
-  char filename[14] = "/NNN.mp3";
-  //search for the sound file
-  int note = sample_now;
-  int nnn = (note % 1000);  // 0~999
-  int nn =  (note % 100);   // 0~99
-  filename[1] = '0' + (nnn / 100); // N__.MP3
-  filename[2] = '0' + (nn / 10);   // _N_.MP3
-  filename[3] = '0' + (nn % 10);   // __N.MP3
-  //TEST
-  Serial.println(filename);
-  screen_filename = String(filename);
-  bool test = SD.exists(filename);
-  if (!test) {
-    Serial.println("... does not exist.");
-    screen_filename = screen_filename + "_!NEXIST!";
-    return;
-  }
-  //stop the player.
-  audio.stopSong();
+    //filename buffer - 8.3 naming convension! 8+1+3+1 = 13
+    // + '/' root symbol 13+1 = 14 (ESP32 specific?)
+    char filename[14] = "/NNN.mp3";
+    //search for the sound file
+    int note = sample_now;
+    int nnn = (note % 1000); // 0~999
+    int nn =  (note % 100); // 0~99
+    filename[1] = '0' + (nnn / 100); // N__.MP3
+    filename[2] = '0' + (nn / 10); // _N_.MP3
+    filename[3] = '0' + (nn % 10); // __N.MP3
+    //TEST
+    Serial.println(filename);
+    screen_filename = String(filename);
+    bool test = SD.exists(filename);
+    if (!test) {
+        Serial.println("... does not exist.");
+        screen_filename = screen_filename + "_!NEXIST!";
+        return;
+    }
+    //stop the player.
+    audio.stopSong();
 }
 Task sample_player_stop_task(0, TASK_ONCE, &sample_player_stop, &runner, false);
 
+//looping
+void looping()
+{
+    if (!audio.isRunning()) {
+        //keep sample_now as it is.
+        sample_player_start_task.restartDelayed(10);
+    }
+}
+Task looping_task(5000, TASK_FOREVER, &looping, &runner, false);
+// Task looping_task(5000, TASK_FOREVER, &looping, &runner, true); // < with looping task .. audio will always keep playing. (non stop.)
+
 //
 #if defined(REPLICATE_NOTE_REQ)
 Note note_now = {
-  -1, // int32_t id;
-  -1, // float pitch;
-  -1, // float velocity;
-  -1, // float onoff;
-  -1, // float x1;
-  -1, // float x2;
-  -1, // float x3;
-  -1, // float x4;
-  -1 // float ps;
+    -1, // int32_t id;
+    -1, // float pitch;
+    -1, // float velocity;
+    -1, // float onoff;
+    -1, // float x1;
+    -1, // float x2;
+    -1, // float x3;
+    -1, // float x4;
+    -1 // float ps;
 };
 #define NEW_NOTE_TIMEOUT (3000)
 static unsigned long new_note_time = (-1*NEW_NOTE_TIMEOUT);
 void repeat() {
-  //
-  uint8_t frm_size = sizeof(Note) + 2;
-  uint8_t frm[frm_size];
-  frm[0] = '[';
-  memcpy(frm + 1, (uint8_t *) &note_now, sizeof(Note));
-  frm[frm_size - 1] = ']';
-  //
-  // strange but following didn't work as expected. (instead, i have to send one-by-one.)
-  // esp_now_send(NULL, frm, frm_size); // to all peers in the list.
+    //
+    uint8_t frm_size = sizeof(Note) + 2;
+    uint8_t frm[frm_size];
+    frm[0] = '[';
+    memcpy(frm + 1, (uint8_t *) &note_now, sizeof(Note));
+    frm[frm_size - 1] = ']';
+    //
+    // strange but following didn't work as expected. (instead, i have to send one-by-one.)
+    // esp_now_send(NULL, frm, frm_size); // to all peers in the list.
 
-  // so, forget about peer list -> just pick a broadcast peer to be sent.
-  uint8_t broadcastmac[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-  esp_now_send(broadcastmac, frm, frm_size);
+    // so, forget about peer list -> just pick a broadcast peer to be sent.
+    uint8_t broadcastmac[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+    esp_now_send(broadcastmac, frm, frm_size);
 
-  // (DEBUG) fetch full peer list
-  { PeerLister a; a.print(); }
+    // (DEBUG) fetch full peer list
+    { PeerLister a; a.print(); }
 
-  //
-  MONITORING_SERIAL.print("\nrepeat! ==> ");
-  MONITORING_SERIAL.println(note_now.to_string());
+    //
+    MONITORING_SERIAL.print("\nrepeat! ==> ");
+    MONITORING_SERIAL.println(note_now.to_string());
 }
 Task repeat_task(0, TASK_ONCE, &repeat, &runner, false);
 #endif
@@ -278,304 +289,304 @@ Task repeat_task(0, TASK_ONCE, &repeat, &runner, false);
 extern Task hello_task;
 static int hello_delay = 0;
 void hello() {
-  //
-  byte mac[6];
-  WiFi.macAddress(mac);
-  uint32_t mac32 = (((((mac[2] << 8) + mac[3]) << 8) + mac[4]) << 8) + mac[5];
-  //
-  Hello hello(String(MY_SIGN), MY_ID, mac32); // the most basic 'hello'
-  // and you can append some floats
-  static int count = 0;
-  count++;
-  hello.h1 = (count % 1000);
-  hello.h2 = sample_now;
-  // hello.h3 = 0;
-  // hello.h4 = 0;
-  //
-  uint8_t frm_size = sizeof(Hello) + 2;
-  uint8_t frm[frm_size];
-  frm[0] = '{';
-  memcpy(frm + 1, (uint8_t *) &hello, sizeof(Hello));
-  frm[frm_size - 1] = '}';
-  //
-  esp_now_send(NULL, frm, frm_size); // to all peers in the list.
-  //
-  // MONITORING_SERIAL.write(frm, frm_size);
-  // MONITORING_SERIAL.println(" ==(esp_now_send/0)==> ");
-  //
-  if (hello_delay > 0) {
-    if (hello_delay < 100) hello_delay = 100;
-    hello_task.restartDelayed(hello_delay);
-  }
+    //
+    byte mac[6];
+    WiFi.macAddress(mac);
+    uint32_t mac32 = (((((mac[2] << 8) + mac[3]) << 8) + mac[4]) << 8) + mac[5];
+    //
+    Hello hello(String(MY_SIGN), MY_ID, mac32); // the most basic 'hello'
+    // and you can append some floats
+    static int count = 0;
+    count++;
+    hello.h1 = (count % 1000);
+    hello.h2 = sample_now;
+    // hello.h3 = 0;
+    // hello.h4 = 0;
+    //
+    uint8_t frm_size = sizeof(Hello) + 2;
+    uint8_t frm[frm_size];
+    frm[0] = '{';
+    memcpy(frm + 1, (uint8_t *) &hello, sizeof(Hello));
+    frm[frm_size - 1] = '}';
+    //
+    esp_now_send(NULL, frm, frm_size); // to all peers in the list.
+    //
+    // MONITORING_SERIAL.write(frm, frm_size);
+    // MONITORING_SERIAL.println(" ==(esp_now_send/0)==> ");
+    //
+    if (hello_delay > 0) {
+        if (hello_delay < 100) hello_delay = 100;
+        hello_task.restartDelayed(hello_delay);
+    }
 }
 Task hello_task(0, TASK_ONCE, &hello, &runner, false);
 
 //task #0 : blink led
 extern Task blink_task;
 void blink() {
-  //
-  static int count = 0;
-  count++;
-  //
-  switch (count % 4) {
-  case 0:
-    digitalWrite(LED_PIN, LOW); // first ON
-    blink_task.delay(LED_ONTIME);
-    break;
-  case 1:
-    digitalWrite(LED_PIN, HIGH); // first OFF
-    blink_task.delay(LED_GAPTIME);
-    break;
-  case 2:
-    digitalWrite(LED_PIN, LOW); // second ON
-    blink_task.delay(LED_ONTIME);
-    break;
-  case 3:
-    digitalWrite(LED_PIN, HIGH); // second OFF
-    blink_task.delay(LED_PERIOD - 2* LED_ONTIME - LED_GAPTIME);
-    break;
-  }
+    //
+    static int count = 0;
+    count++;
+    //
+    switch (count % 4) {
+    case 0:
+        digitalWrite(LED_PIN, LOW); // first ON
+        blink_task.delay(LED_ONTIME);
+        break;
+    case 1:
+        digitalWrite(LED_PIN, HIGH); // first OFF
+        blink_task.delay(LED_GAPTIME);
+        break;
+    case 2:
+        digitalWrite(LED_PIN, LOW); // second ON
+        blink_task.delay(LED_ONTIME);
+        break;
+    case 3:
+        digitalWrite(LED_PIN, HIGH); // second OFF
+        blink_task.delay(LED_PERIOD - 2* LED_ONTIME - LED_GAPTIME);
+        break;
+    }
 }
 Task blink_task(0, TASK_FOREVER, &blink, &runner, false); // makepython esp32 has NO led => disabled.
 
 // on 'Note'
 void onNoteHandler(Note & n) {
-  //is it for me?
-  if (n.id == MY_GROUP_ID || n.id == MY_ID) {
-    //
-    screen_cmd = n.to_string();
-    screen_cmd_notify_task.restart();
-    //
-    if (n.velocity != 0 || n.onoff == 2) {
-      audio.setVolume(n.velocity * 21 / 127 * GAIN_MAX); // 0...127 ==> 0...21
+    //is it for me?
+    if (n.id == MY_GROUP_ID || n.id == MY_ID) {
+        //
+        screen_cmd = n.to_string();
+        screen_cmd_notify_task.restart();
+        //
+        if (n.velocity != 0 || n.onoff == 2) {
+            audio.setVolume(n.velocity * 21 / 127 * GAIN_MAX); // 0...127 ==> 0...21
+        }
+        //
+        if (n.onoff == 1) {
+            // filter out re-triggering same note while it is playing.
+            if (!audio.isRunning() || sample_now != n.pitch) {
+                sample_now = n.pitch;
+                sample_player_start_task.restartDelayed(10);
+            }
+        } else if (n.onoff == 0) {
+            sample_now = n.pitch;
+            sample_player_stop_task.restartDelayed(10);
+        }
+        //
     }
-    //
-    if (n.onoff == 1) {
-      // filter out re-triggering same note while it is playing.
-      if (!audio.isRunning() || sample_now != n.pitch) {
-        sample_now = n.pitch;
-        sample_player_start_task.restartDelayed(10);
-      }
-    } else if (n.onoff == 0) {
-      sample_now = n.pitch;
-      sample_player_stop_task.restartDelayed(10);
-    }
-    //
-  }
 }
 
 // on 'receive'
 void onDataReceive(const uint8_t * mac, const uint8_t *incomingData, int32_t len) {
 
-  //
-  // MONITORING_SERIAL.write(incomingData, len);
+    //
+    // MONITORING_SERIAL.write(incomingData, len);
 
-  //
+    //
 #if defined(HAVE_CLIENT)
-  Serial.write(incomingData, len); // we pass it over to the client.
+    Serial.write(incomingData, len); // we pass it over to the client.
 #endif
 
-  // open => identify => use.
-  if (incomingData[0] == '{' && incomingData[len - 1] == '}' && len == (sizeof(Hello) + 2)) {
-    Hello hello("");
-    memcpy((uint8_t *) &hello, incomingData + 1, sizeof(Hello));
-    //
-    MONITORING_SERIAL.println(hello.to_string());
-    //
-  }
-
-  // open => identify => use.
-  if (incomingData[0] == '[' && incomingData[len - 1] == ']' && len == (sizeof(Note) + 2)) {
-    Note note;
-    memcpy((uint8_t *) &note, incomingData + 1, sizeof(Note));
-    onNoteHandler(note);
-
-    //is it for me?
-    if (note.id == MY_GROUP_ID || note.id == MY_ID) {
-      hello_delay = note.ps;
-      if (hello_delay > 0 && hello_task.isEnabled() == false) {
-        hello_task.restart();
-      }
+    // open => identify => use.
+    if (incomingData[0] == '{' && incomingData[len - 1] == '}' && len == (sizeof(Hello) + 2)) {
+        Hello hello("");
+        memcpy((uint8_t *) &hello, incomingData + 1, sizeof(Hello));
+        //
+        MONITORING_SERIAL.println(hello.to_string());
+        //
     }
 
-    MONITORING_SERIAL.println(note.to_string());
+    // open => identify => use.
+    if (incomingData[0] == '[' && incomingData[len - 1] == ']' && len == (sizeof(Note) + 2)) {
+        Note note;
+        memcpy((uint8_t *) &note, incomingData + 1, sizeof(Note));
+        onNoteHandler(note);
+
+        //is it for me?
+        if (note.id == MY_GROUP_ID || note.id == MY_ID) {
+            hello_delay = note.ps;
+            if (hello_delay > 0 && hello_task.isEnabled() == false) {
+                hello_task.restart();
+            }
+        }
+
+        MONITORING_SERIAL.println(note.to_string());
 
     #if defined(REPLICATE_NOTE_REQ)
-    if (millis() - new_note_time > NEW_NOTE_TIMEOUT) {
-      note_now = note;
-      repeat_task.restart();
-      new_note_time = millis();
-    }
+        if (millis() - new_note_time > NEW_NOTE_TIMEOUT) {
+            note_now = note;
+            repeat_task.restart();
+            new_note_time = millis();
+        }
     #endif
-  }
+    }
 }
 
 // on 'sent'
 void onDataSent(const uint8_t *mac_addr, esp_now_send_status_t sendStatus) {
-  // well, i think this cb should be called once for EVERY single TX attempts,
-  //   but in reality, it doesn't get called that often.
-  //   i think this is sorta bug. but have no clear clue.
-  MONITORING_SERIAL.printf("* delivery attempt! ~~~>>> %02X:%02X:%02X:%02X:%02X:%02X\n", mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
-  if (sendStatus != 0) MONITORING_SERIAL.printf("* ==>> FAILED :(\n\n");
+    // well, i think this cb should be called once for EVERY single TX attempts,
+    //   but in reality, it doesn't get called that often.
+    //   i think this is sorta bug. but have no clear clue.
+    MONITORING_SERIAL.printf("* delivery attempt! ~~~>>> %02X:%02X:%02X:%02X:%02X:%02X\n", mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
+    if (sendStatus != 0) MONITORING_SERIAL.printf("* ==>> FAILED :(\n\n");
 }
 
 // SD TEST
 void printDirectory(File dir, int numTabs) {
-  // char filename[256] = "";
-  while(true) {
-    File entry =  dir.openNextFile();
-    if (!entry) {
-      // no more files
-      break;
+    // char filename[256] = "";
+    while(true) {
+        File entry =  dir.openNextFile();
+        if (!entry) {
+            // no more files
+            break;
+        }
+        for (uint8_t i=0; i<numTabs; i++) {
+            Serial.print('\t');
+        }
+        // entry.getName(filename, 256);
+        // Serial.print(filename);
+        Serial.print(entry.name());
+        if (entry.isDirectory()) {
+            Serial.println("/");
+            //non-recursive listing...
+            // printDirectory(entry, numTabs+1);
+        } else {
+            // files have sizes, directories do not
+            Serial.print("\t\t");
+            Serial.println(entry.size(), DEC);
+        }
+        entry.close();
     }
-    for (uint8_t i=0; i<numTabs; i++) {
-      Serial.print('\t');
-    }
-    // entry.getName(filename, 256);
-    // Serial.print(filename);
-    Serial.print(entry.name());
-    if (entry.isDirectory()) {
-      Serial.println("/");
-      //non-recursive listing...
-      // printDirectory(entry, numTabs+1);
-    } else {
-      // files have sizes, directories do not
-      Serial.print("\t\t");
-      Serial.println(entry.size(), DEC);
-    }
-    entry.close();
-  }
 }
 
 void lcd_text(String str) {
-  display.clearDisplay();
-  display.setTextColor(SSD1306_WHITE);
-  display.setTextSize(1);
-  display.setCursor(0, 0);
-  display.println(str.c_str());
-  display.display();
+    display.clearDisplay();
+    display.setTextColor(SSD1306_WHITE);
+    display.setTextSize(1);
+    display.setCursor(0, 0);
+    display.println(str.c_str());
+    display.display();
 }
 
 //
 File root;
 void setup() {
 
-  //led
-  pinMode(LED_PIN, OUTPUT);
+    //led
+    pinMode(LED_PIN, OUTPUT);
 
-  //serial
-  Serial.begin(115200);
-  delay(100);
+    //serial
+    Serial.begin(115200);
+    delay(100);
 
-  //screen
-  Wire.begin(MAKEPYTHON_ESP32_SDA, MAKEPYTHON_ESP32_SCL);
-  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
-  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x32
-    Serial.println(F("SSD1306 allocation failed"));
-    for (;;)
-      ;         // Don't proceed, loop forever
-  }
-  display.clearDisplay();
+    //screen
+    Wire.begin(MAKEPYTHON_ESP32_SDA, MAKEPYTHON_ESP32_SCL);
+    // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
+    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x32
+        Serial.println(F("SSD1306 allocation failed"));
+        for (;;)
+            ;   // Don't proceed, loop forever
+    }
+    display.clearDisplay();
 
-  //SD(SPI)
-  pinMode(SD_CS, OUTPUT);
-  digitalWrite(SD_CS, HIGH);
-  SPI.begin(SPI_SCK, SPI_MISO, SPI_MOSI);
-  SPI.setFrequency(1000000);
-  if (!SD.begin(SD_CS, SPI)) {
-    Serial.println("Card Mount Failed");
-    lcd_text("SD ERR!\nCard Mount Failed!");
-    while (1)
-      ;
-  } else {
-    // lcd_text("SD OK");
-  }
-  root = SD.open("/");
-  printDirectory(root, 0);
+    //SD(SPI)
+    pinMode(SD_CS, OUTPUT);
+    digitalWrite(SD_CS, HIGH);
+    SPI.begin(SPI_SCK, SPI_MISO, SPI_MOSI);
+    SPI.setFrequency(1000000);
+    if (!SD.begin(SD_CS, SPI)) {
+        Serial.println("Card Mount Failed");
+        lcd_text("SD ERR!\nCard Mount Failed!");
+        while (1)
+            ;
+    } else {
+        // lcd_text("SD OK");
+    }
+    root = SD.open("/");
+    printDirectory(root, 0);
 
-  //audio(I2S)
-  audio.setPinout(I2S_BCLK, I2S_LRC, I2S_DOUT);
-  // audio.setVolume(21);   // 0...21
-  audio.setVolume(14.88);   // 90 * 21 / 127 == 14.88
+    //audio(I2S)
+    audio.setPinout(I2S_BCLK, I2S_LRC, I2S_DOUT);
+    // audio.setVolume(21);   // 0...21
+    audio.setVolume(14.88); // 90 * 21 / 127 == 14.88
 
-  // audio.connecttoFS(SD, filename.c_str());
+    // audio.connecttoFS(SD, filename.c_str());
 
-  //info
-  Serial.println();
-  Serial.println();
-  Serial.println("\"hi, i m your postman.\"");
-  Serial.println("-");
-  Serial.println("- my id: " + String(MY_ID) + ", gid: " + String(MY_GROUP_ID) + ", call me ==> \"" + String(MY_SIGN) + "\"");
-  Serial.println("- mac address: " + WiFi.macAddress() + ", channel: " + String(WIFI_CHANNEL));
-  Serial.println("- my peer book ==> \"" + String(ADDRESSBOOK_TITLE) + "\"");
+    //info
+    Serial.println();
+    Serial.println();
+    Serial.println("\"hi, i m your postman.\"");
+    Serial.println("-");
+    Serial.println("- my id: " + String(MY_ID) + ", gid: " + String(MY_GROUP_ID) + ", call me ==> \"" + String(MY_SIGN) + "\"");
+    Serial.println("- mac address: " + WiFi.macAddress() + ", channel: " + String(WIFI_CHANNEL));
+    Serial.println("- my peer book ==> \"" + String(ADDRESSBOOK_TITLE) + "\"");
 #if defined(HAVE_CLIENT)
-  Serial.println("- ======== 'HAVE_CLIENT' ========");
+    Serial.println("- ======== 'HAVE_CLIENT' ========");
 #endif
 #if defined(SERIAL_SWAP)
-  Serial.println("- ======== 'SERIAL_SWAP' ========");
+    Serial.println("- ======== 'SERIAL_SWAP' ========");
 #endif
 #if defined(DISABLE_AP)
-  Serial.println("- ======== 'DISABLE_AP' ========");
+    Serial.println("- ======== 'DISABLE_AP' ========");
 #endif
 #if defined(HAVE_CLIENT_I2C)
-  Serial.println("- ======== 'HAVE_CLIENT_I2C' ========");
+    Serial.println("- ======== 'HAVE_CLIENT_I2C' ========");
 #endif
 #if defined(REPLICATE_NOTE_REQ)
-  Serial.println("- ======== 'REPLICATE_NOTE_REQ' ========");
+    Serial.println("- ======== 'REPLICATE_NOTE_REQ' ========");
 #endif
-  Serial.println("-");
+    Serial.println("-");
 
-  //wifi
-  WiFiMode_t node_type = WIFI_AP_STA;
+    //wifi
+    WiFiMode_t node_type = WIFI_AP_STA;
 #if defined(DISABLE_AP)
-  // system_phy_set_max_tpw(0);
-  WiFi.setTxPower(WIFI_POWER_MINUS_1dBm); // Set WiFi RF power output to lowest level
-  node_type = WIFI_STA;
+    // system_phy_set_max_tpw(0);
+    WiFi.setTxPower(WIFI_POWER_MINUS_1dBm); // Set WiFi RF power output to lowest level
+    node_type = WIFI_STA;
 #endif
-  WiFi.mode(node_type);
+    WiFi.mode(node_type);
 
-  //esp-now
-  if (esp_now_init() != 0) {
-    Serial.println("Error initializing ESP-NOW");
-    return;
-  }
-  esp_now_register_send_cb(onDataSent);
-  esp_now_register_recv_cb(onDataReceive);
-  //
-  // Serial.println("- ! (esp_now_add_peer) ==> add a 'broadcast peer' (FF:FF:FF:FF:FF:FF).");
-  // uint8_t broadcastmac[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-  //
-  // //
-  // esp_now_peer_info_t peerInfo = {};
-  // memcpy(peerInfo.peer_addr, broadcastmac, 6);
-  // peerInfo.channel = 0;
-  // peerInfo.encrypt = false;
-  // esp_now_add_peer(&peerInfo);
+    //esp-now
+    if (esp_now_init() != 0) {
+        Serial.println("Error initializing ESP-NOW");
+        return;
+    }
+    esp_now_register_send_cb(onDataSent);
+    esp_now_register_recv_cb(onDataReceive);
+    //
+    // Serial.println("- ! (esp_now_add_peer) ==> add a 'broadcast peer' (FF:FF:FF:FF:FF:FF).");
+    // uint8_t broadcastmac[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+    //
+    // //
+    // esp_now_peer_info_t peerInfo = {};
+    // memcpy(peerInfo.peer_addr, broadcastmac, 6);
+    // peerInfo.channel = 0;
+    // peerInfo.encrypt = false;
+    // esp_now_add_peer(&peerInfo);
 
-  AddressBook * book = lib.getBookByTitle(ADDRESSBOOK_TITLE);
-  if (book == NULL) {
-    Serial.println("- ! wrong book !! : \"" + String(ADDRESSBOOK_TITLE) + "\""); while(1);
-  }
-  for (int idx = 0; idx < book->list.size(); idx++) {
-    Serial.println("- ! (esp_now_add_peer) ==> add a '" + book->list[idx].name + "'.");
-    esp_now_peer_info_t peerInfo = {};
-    memcpy(peerInfo.peer_addr, book->list[idx].mac, 6);
-    peerInfo.channel = 0;
-    peerInfo.encrypt = false;
-    esp_now_add_peer(&peerInfo);
-  }
-  // (DEBUG) fetch full peer list
-  { PeerLister a; a.print(); }
-  //
-  Serial.println("-");
-  Serial.println("\".-.-.-. :)\"");
-  Serial.println();
+    AddressBook * book = lib.getBookByTitle(ADDRESSBOOK_TITLE);
+    if (book == NULL) {
+        Serial.println("- ! wrong book !! : \"" + String(ADDRESSBOOK_TITLE) + "\""); while(1);
+    }
+    for (int idx = 0; idx < book->list.size(); idx++) {
+        Serial.println("- ! (esp_now_add_peer) ==> add a '" + book->list[idx].name + "'.");
+        esp_now_peer_info_t peerInfo = {};
+        memcpy(peerInfo.peer_addr, book->list[idx].mac, 6);
+        peerInfo.channel = 0;
+        peerInfo.encrypt = false;
+        esp_now_add_peer(&peerInfo);
+    }
+    // (DEBUG) fetch full peer list
+    { PeerLister a; a.print(); }
+    //
+    Serial.println("-");
+    Serial.println("\".-.-.-. :)\"");
+    Serial.println();
 }
 
 void loop() {
-  //
-  audio.loop();
-  //
-  runner.execute();
-  //
+    //
+    audio.loop();
+    //
+    runner.execute();
+    //
 }