hardware button support

display/low_level_display_epaper.cpp

@@ -3,8 +3,13 @@
 #include <stdlib.h>
 #include <string.h>
 
-// Note: This is a placeholder implementation
-// You'll need to add the actual e-paper driver code to lib/epaper/
+// Waveshare 4.2" e-Paper monochrome driver (supports partial refresh)
+extern "C" {
+    #include "EPD_4in2_V2.h"
+    #include "DEV_Config.h"
+}
+
+// Note: EPD_4IN2_V2 is monochrome (black/white) and supports fast partial refresh
 
 LowLevelDisplayEPaper::LowLevelDisplayEPaper(const epaper_config* cfg, int w, int h)
     : config(cfg), width(w), height(h), initialized(false), framebuffer(nullptr), dirty(false) {
@@ -33,11 +38,15 @@ bool LowLevelDisplayEPaper::init() {
         return false;
     }
     
-    // TODO: Implement e-paper initialization
-    // epaper_init(config, width, height);
-    printf("E-paper display initialized: %dx%d (stub)\n", width, height);
+    printf("Initializing Waveshare 4.2\" e-Paper display (%dx%d)...\n", width, height);
+    
+    // Initialize Waveshare driver (handles GPIO and SPI setup)
+    DEV_Module_Init();
+    EPD_4IN2_V2_Init();
+    
+    printf("E-paper display initialized successfully (partial refresh enabled)\n");
     initialized = true;
-    return false;  // Return false until actual driver is implemented
+    return true;
 }
 
 void LowLevelDisplayEPaper::clear(bool white) {
@@ -79,19 +88,56 @@ void LowLevelDisplayEPaper::refresh() {
         return;
     }
     
-    // TODO: Implement actual e-paper refresh
-    // epaper_update(framebuffer);
-    printf("E-paper refresh (stub)\n");
+    if (!initialized) {
+        printf("E-paper not initialized, cannot refresh\n");
+        return;
+    }
     
+    printf("Refreshing e-paper display (partial refresh)...\n");
+    
+    // Use partial refresh for fast updates (~1 second instead of ~15 seconds)
+    // Partial refresh updates only the changed pixels
+    EPD_4IN2_V2_PartialDisplay(framebuffer, 0, 0, EPD_4IN2_V2_WIDTH, EPD_4IN2_V2_HEIGHT);
+    
+    printf("E-paper partial refresh complete\n");
     dirty = false;
 }
 
 void LowLevelDisplayEPaper::clear_display() {
-    clear(true);  // Fill with white
-    refresh();
+    if (!initialized) {
+        printf("E-paper not initialized, cannot clear\n");
+        return;
+    }
+    
+    printf("Clearing e-paper display...\n");
+    EPD_4IN2_V2_Clear();
+    
+    // Also clear framebuffer
+    clear(true);
+    dirty = false;  // Already refreshed by EPD_4IN2_V2_Clear
+}
+
+void LowLevelDisplayEPaper::full_refresh() {
+    if (!framebuffer || !initialized) {
+        printf("E-paper not initialized or no framebuffer\n");
+        return;
+    }
+    
+    printf("Performing full refresh (removes ghosting, ~15 seconds)...\n");
+    
+    // Full refresh uses EPD_4IN2_V2_Display for complete screen update
+    // This is slower but removes any ghosting from partial refreshes
+    EPD_4IN2_V2_Display(framebuffer);
+    
+    printf("Full refresh complete\n");
+    dirty = false;
 }
 
 void LowLevelDisplayEPaper::sleep() {
-    // TODO: Implement e-paper sleep mode
-    // epaper_sleep();
+    if (!initialized) {
+        return;
+    }
+    
+    printf("Putting e-paper display to sleep...\n");
+    EPD_4IN2_V2_Sleep();
 }