Implement UX improvements: status LED, long press slideshow toggle

sound_picture_app/sound_picture_app.ino

@@ -5,12 +5,32 @@
 #include <algorithm>
 
 #define BOOT_KEY_PIN 9
+#define PIN_NEOPIXEL 38
+
+// Playback states
+enum AppState {
+  STATE_IDLE,
+  STATE_PLAYING,
+  STATE_AUTOPLAY,
+  STATE_ERROR
+};
+
+AppState currentState = STATE_IDLE;
+bool hasError = false;
 
 uint16_t currentIndex = 0;
 bool lastButtonState = HIGH;
 uint32_t lastDebounceTime = 0;
 const uint32_t debounceDelay = 50;
-bool buttonWasPressed = false;
+
+// Slide Show timing
+uint32_t lastSlideTime = 0;
+const uint32_t slideShowInterval = 5000; // 5 seconds
+
+// Pulse control for RGB LED
+uint32_t lastLedPulseTime = 0;
+uint8_t pulseBrightness = 0;
+bool pulseDirection = true;
 
 void setup() {
   Serial.begin(115200);
@@ -20,6 +40,10 @@ void setup() {
   printf("Starting Sound and Picture Player...\r\n");
   printf("==========================================\r\n");
   
+  // Setup NeoPixel
+  pinMode(PIN_NEOPIXEL, OUTPUT);
+  neopixelWrite(PIN_NEOPIXEL, 0, 0, 0); // turn off initially
+  
   // Initialize peripherals
   Flash_test();
   SD_Init();
@@ -36,11 +60,14 @@ void setup() {
   printf("Initialization complete!\r\n");
   printf("Found %d PNG images and %d WAV soundbites.\r\n", Image_Count, Wav_Count);
   
-  if (Image_Count > 0) {
+  if (Image_Count == 0 || Wav_Count == 0) {
+    hasError = true;
+    currentState = STATE_ERROR;
+    printf("ERROR: No media found on microSD card!\r\n");
+  } else {
     printf("Displaying initial image (index 0): %s\r\n", Image_Names[0]);
     Display_Image_By_Index("/", 0);
-  } else {
-    printf("WARNING: No PNG images found in SD Card root directory!\r\n");
+    currentState = STATE_IDLE;
   }
 }
 
@@ -70,31 +97,110 @@ void playCurrentPair() {
   }
 }
 
+void updateLEDStatus() {
+  uint32_t now = millis();
+  
+  // Pulse animation frequency
+  if (now - lastLedPulseTime > 15) {
+    lastLedPulseTime = now;
+    if (pulseDirection) {
+      pulseBrightness += 2;
+      if (pulseBrightness >= 120) pulseDirection = false;
+    } else {
+      pulseBrightness -= 2;
+      if (pulseBrightness <= 10) pulseDirection = true;
+    }
+  }
+
+  // Update LED color based on state
+  if (hasError) {
+    // Flashing red
+    if ((now / 250) % 2 == 0) {
+      neopixelWrite(PIN_NEOPIXEL, 64, 0, 0); // Dim Red
+    } else {
+      neopixelWrite(PIN_NEOPIXEL, 0, 0, 0);
+    }
+  } 
+  else if (isWavPlaying()) {
+    // Pulsing Green
+    neopixelWrite(PIN_NEOPIXEL, 0, pulseBrightness, 0);
+  } 
+  else if (currentState == STATE_AUTOPLAY) {
+    // Pulsing Purple (Red + Blue)
+    neopixelWrite(PIN_NEOPIXEL, pulseBrightness / 2, 0, pulseBrightness);
+  } 
+  else {
+    // Solid Blue
+    neopixelWrite(PIN_NEOPIXEL, 0, 0, 32);
+  }
+}
+
 void loop() {
   bool currentButtonReading = digitalRead(BOOT_KEY_PIN);
+  static uint32_t buttonPressStartTime = 0;
+  static bool buttonWasHeld = false;
   
+  // Detect changes in button state
   if (currentButtonReading != lastButtonState) {
     lastDebounceTime = millis();
+    if (currentButtonReading == LOW) {
+      buttonPressStartTime = millis();
+      buttonWasHeld = false;
+    }
   }
   
   if ((millis() - lastDebounceTime) > debounceDelay) {
     if (currentButtonReading == LOW) {
-      if (!buttonWasPressed) {
-        buttonWasPressed = true;
-        printf("Button pressed! Cycling to next picture and playing sound...\r\n");
-        
-        if (Image_Count > 0 || Wav_Count > 0) {
-          playCurrentPair();
-          currentIndex = (currentIndex + 1) % std::max(Image_Count, Wav_Count);
-        } else {
-          printf("No media found on SD card to cycle!\r\n");
+      // Button is being held down. Check if it exceeds long-press threshold (1.5 seconds)
+      if (!buttonWasHeld && (millis() - buttonPressStartTime > 1500)) {
+        buttonWasHeld = true; // Mark as held to prevent repeated triggers
+        if (!hasError) {
+          if (currentState == STATE_AUTOPLAY) {
+            currentState = STATE_IDLE;
+            printf("Autoplay Disabled. Manual Mode active.\r\n");
+            stopWav();
+          } else {
+            currentState = STATE_AUTOPLAY;
+            printf("Autoplay Enabled! Cycling slides every %d ms.\r\n", slideShowInterval);
+            lastSlideTime = millis();
+            playCurrentPair();
+          }
         }
       }
     } else {
-      buttonWasPressed = false;
+      // Button was released
+      if (lastButtonState == LOW && !buttonWasHeld) {
+        // Single press trigger
+        printf("Single press detected!\r\n");
+        if (!hasError) {
+          if (currentState == STATE_AUTOPLAY) {
+            currentState = STATE_IDLE;
+            printf("Autoplay Disabled via manual navigation.\r\n");
+          }
+          playCurrentPair();
+          currentIndex = (currentIndex + 1) % std::max(Image_Count, Wav_Count);
+        } else {
+          printf("System in error state (missing files). Can't cycle.\r\n");
+        }
+      }
+      buttonWasHeld = false;
+    }
+  }
+  
+  // Handle slideshow auto-advance in Autoplay mode
+  if (currentState == STATE_AUTOPLAY && !hasError) {
+    // Advance if the audio finished playing and 5 seconds has elapsed
+    if (!isWavPlaying() && (millis() - lastSlideTime > slideShowInterval)) {
+      lastSlideTime = millis();
+      currentIndex = (currentIndex + 1) % std::max(Image_Count, Wav_Count);
+      playCurrentPair();
     }
   }
   
   lastButtonState = currentButtonReading;
+  
+  // Update status RGB LED
+  updateLEDStatus();
+  
   delay(10); // Yield to other RTOS tasks
 }