fix: handle critical bug

Avoid making it get stuck in the main loop

Esp32_Code/INFOSCREEN_WITH_INTERVAL/INFOSCREEN_WITH_INTERVAL.ino

@@ -23,7 +23,6 @@ uint64_t sleepDuration = 30e6; // Default 30 seconds in microseconds
 #define EPD_HEIGHT EPD_7IN5B_V2_HEIGHT
 
 // =========== IMAGE TUNING PARAMETERS ===========
-// These will be updated from the configuration
 uint8_t blackTextThreshold = 190;  // Default (0-255)
 bool enableDithering = true;       // Default
 uint8_t ditherStrength = 8;        // Default (8-32)
@@ -42,11 +41,49 @@ int16_t *errorB = NULL;
 // Create an instance of the JPEG decoder
 JPEGDEC jpeg;
 
+// Forward declarations
+bool fetchConnectionInformation();
+void fetchAndDisplayImage();
+void clearDisplay();
+
+// Centralized cleanup + deep sleep
+void finishAndSleep(const char* reason) {
+  Serial.println();
+  Serial.println("========== Going to deep sleep ==========");
+  if (reason && reason[0]) {
+    Serial.print("Reason: ");
+    Serial.println(reason);
+  }
+
+  // Free dithering buffers if allocated
+  if (errorR) { free(errorR); errorR = NULL; }
+  if (errorG) { free(errorG); errorG = NULL; }
+  if (errorB) { free(errorB); errorB = NULL; }
+
+  // Put display to sleep (safe to call even if already sleeping)
+  EPD_7IN5B_V2_Sleep();
+
+  // Free framebuffers
+  if (BlackImage) { free(BlackImage); BlackImage = NULL; }
+  if (RYImage) { free(RYImage); RYImage = NULL; }
+
+  // Tidy up WiFi to save power before deep sleep
+  WiFi.disconnect(true, true);
+  WiFi.mode(WIFI_OFF);
+  delay(50);
+
+  Serial.print("Sleeping for ");
+  Serial.print(sleepDuration / 60000000);
+  Serial.println(" minutes");
+  esp_sleep_enable_timer_wakeup(sleepDuration);
+  esp_deep_sleep_start();
+}
+
 // Apply contrast adjustment to RGB values
 void adjustContrast(uint8_t *r, uint8_t *g, uint8_t *b) {
   if (!enhanceContrast) return;
 
-  float contrast = (contrastLevel / 100.0) + 1.0;  // Convert to decimal & shift range: [0..2]
+  float contrast = (contrastLevel / 100.0) + 1.0;  // [1..2]
   float intercept = 128 * (1 - contrast);
 
   *r = constrain((*r * contrast) + intercept, 0, 255);
@@ -240,7 +277,8 @@ void setup() {
 
   if ((BlackImage == NULL) || (RYImage == NULL)) {
     Serial.println("Failed to allocate memory for framebuffers!");
-    while(1); // Halt if memory allocation fails
+    // Even on failure, deep-sleep to allow recovery on next boot
+    finishAndSleep("Framebuffer allocation failed");
   }
 
   // Initialize e-ink display exactly as in Waveshare example
@@ -256,6 +294,7 @@ void setup() {
   Serial.println("Buffers allocated and cleared");
 
   // Connect to WiFi
+  WiFi.mode(WIFI_STA);
   WiFi.begin(ssid, password);
   Serial.print("Connecting to WiFi");
   int wifiAttempts = 0;
@@ -273,7 +312,8 @@ void setup() {
   } else {
     Serial.println();
     Serial.println("WiFi connection failed!");
-    return;
+    // IMPORTANT: Do not just return; always deep sleep so we retry later
+    finishAndSleep("WiFi connection failed");
   }
 
   // Test connectivity to server and get configuration
@@ -285,27 +325,8 @@ void setup() {
     Serial.println("Server connectivity test failed - skipping image fetch");
   }
 
-  // Free dithering buffers if allocated
-  if (errorR) free(errorR);
-  if (errorG) free(errorG);
-  if (errorB) free(errorB);
-  errorR = errorG = errorB = NULL;
-
-  // Put display to sleep
-  EPD_7IN5B_V2_Sleep();
-
-  // Free framebuffers
-  free(BlackImage);
-  free(RYImage);
-  BlackImage = NULL;
-  RYImage = NULL;
-
-  // Enter deep sleep
-  Serial.print("Going to sleep for ");
-  Serial.print(sleepDuration / 60000000);
-  Serial.println(" minutes");
-  esp_sleep_enable_timer_wakeup(sleepDuration);
-  esp_deep_sleep_start();
+  // Always finish with cleanup and deep sleep (success or failure)
+  finishAndSleep("Normal cycle complete");
 }
 
 bool fetchConnectionInformation() {
@@ -491,6 +512,7 @@ void fetchAndDisplayImage() {
           } else {
             totalBytesRead += bytesRead;
           }
+          yield(); // keep WiFi stack happy
         }
         Serial.print("Total bytes read: ");
         Serial.println(totalBytesRead);