Add pre-packaged dependency libraries (ESP32-audioI2S and PNGdec)

libraries/ESP32-audioI2S/examples/plays all files in a directory/plays_all_files_in_a_directory.ino

@@ -0,0 +1,98 @@
+#include "Arduino.h"
+#include "Audio.h"
+#include "SD_MMC.h"
+#include "FS.h"
+#include <vector>
+
+#define I2S_LRC     26
+#define I2S_DOUT    25
+#define I2S_BCLK    27
+
+#define SD_MMC_D0   2
+#define SD_MMC_CLK  14
+#define SD_MMC_CMD  15
+
+void listDir(fs::FS &fs, const char * dirname, uint8_t levels); //proto
+std::vector<char*>  v_audioContent;
+int pirPin = 4;
+Audio audio;
+
+File dir;
+const char audioDir[] = "/mp3";
+
+void my_audio_info(Audio::msg_t m) {
+    Serial.printf("%s: %s\n", m.s, m.msg);
+}
+
+void setup() {
+    Audio::audio_info_callback = my_audio_info;
+    Serial.begin(115200);
+    pinMode(SD_MMC_D0, INPUT_PULLUP);
+    SD_MMC.setPins(SD_MMC_CLK,SD_MMC_CMD, SD_MMC_D0);
+    if(!SD_MMC.begin( "/sdmmc", true, false, 20000)){
+        Serial.println("Card Mount Failed");
+        return;
+    }
+    audio.setPinout(I2S_BCLK, I2S_LRC, I2S_DOUT);
+    audio.setVolume(17); // 0...21 Will need to add a volume setting in the app
+    dir = SD_MMC.open(audioDir);
+    listDir(SD_MMC, audioDir, 1);
+    if(v_audioContent.size() > 0){
+        const char* s = (const char*)v_audioContent[v_audioContent.size() -1];
+        Serial.printf("playing %s\n", s);
+        audio.connecttoFS(SD_MMC, s);
+        v_audioContent.pop_back();
+    }
+}
+
+void loop(){
+    audio.loop();
+    vTaskDelay(1);    // Audio is distoreted without this
+}
+
+void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
+    Serial.printf("Listing directory: %s\n", dirname);
+
+    File root = fs.open(dirname);
+    if(!root){
+        Serial.println("Failed to open directory");
+        return;
+    }
+    if(!root.isDirectory()){
+        Serial.println("Not a directory");
+        return;
+    }
+
+    File file = root.openNextFile();
+    while(file){
+        if(file.isDirectory()){
+            Serial.print("  DIR : ");
+            Serial.println(file.name());
+            if(levels){
+                listDir(fs, file.path(), levels -1);
+            }
+        } else {
+            Serial.print("  FILE: ");
+            Serial.print(file.name());
+            Serial.print("  SIZE: ");
+            Serial.println(file.size());
+            v_audioContent.insert(v_audioContent.begin(), strdup(file.path()));
+        }
+        file = root.openNextFile();
+    }
+    Serial.printf("num files %i", v_audioContent.size());
+    root.close();
+    file.close();
+}
+
+void vector_clear_and_shrink(vector<char*>&vec){
+    uint size = vec.size();
+    for (int i = 0; i < size; i++) {
+        if(vec[i]){
+            free(vec[i]);
+            vec[i] = NULL;
+        }
+    }
+    vec.clear();
+    vec.shrink_to_fit();
+}