add spi e-ink display

CMakeLists.txt

@@ -39,12 +39,25 @@ if (TARGET tinyusb_device)
             add_executable(hello_usb
                 hello_usb.cpp
                 display.cpp
+                commands/echo.cpp
                 )
 
-    add_subdirectory(pico-ssd1306)
+    add_subdirectory(pico-ssd1306 commands)
+    add_subdirectory(Pico_ePaper_Code/c/lib/Config)
+    add_subdirectory(Pico_ePaper_Code/c/lib/e-Paper)
+    add_subdirectory(Pico_ePaper_Code/c/lib/Fonts)
+    add_subdirectory(Pico_ePaper_Code/c/lib/GUI)
+
+    # Add include directories for e-Paper
+    target_include_directories(hello_usb PRIVATE 
+        ${CMAKE_CURRENT_SOURCE_DIR}/Pico_ePaper_Code/c/lib/Config
+        ${CMAKE_CURRENT_SOURCE_DIR}/Pico_ePaper_Code/c/lib/e-Paper
+        ${CMAKE_CURRENT_SOURCE_DIR}/Pico_ePaper_Code/c/lib/Fonts
+        ${CMAKE_CURRENT_SOURCE_DIR}/Pico_ePaper_Code/c/lib/GUI
+    )
 
     # pull in common dependencies
-    target_link_libraries(hello_usb pico_stdlib pico_ssd1306 hardware_i2c)
+    target_link_libraries(hello_usb pico_stdlib pico_ssd1306 hardware_i2c Config ePaper GUI Fonts hardware_spi)
 
     # enable usb output, disable uart output
     pico_enable_stdio_usb(hello_usb 1)

commands/echo.cpp

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <ctype.h>
+#include <cstring>
+
+#include "echo.h"
+
+// Helper function to handle the echoing and resetting of the buffer
+void echo_and_reset(char* buffer, int* index_ptr) {
+    if (*index_ptr > 0) {
+        buffer[*index_ptr] = '\0';
+        // Print to USB serial (ALL CAPS)
+        printf("\nEchoed (ALL CAPS): ");
+        for (int i = 0; buffer[i] != '\0'; i++) {
+            char ch = toupper(buffer[i]);
+            printf("%c", ch);
+        }
+        printf("\n");
+    }
+
+    *index_ptr = 0;
+    printf("> ");
+}

commands/echo.h

@@ -0,0 +1,14 @@
+#ifndef COMMANDS_ECHO_H
+#define COMMANDS_ECHO_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void echo_and_reset(char* buffer, int* index_ptr);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // COMMANDS_ECHO_H

hello_usb.cpp

@@ -1,6 +1,7 @@
 /*
  * Simple USB Serial Echo Program with Timeout, Reconnect, and Backspace Logic.
  * Converted to C++ so the project can use the `pico-ssd1306` C++ library.
+ * Integrated with e-ink display support via Pico_ePaper library.
  */
 
 #include "pico/stdlib.h"
@@ -8,12 +9,101 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <cstring>
+#include <stdlib.h>
 
 #include "display.h"
+#include "commands/echo.h"
+
+// e-Paper library includes
+extern "C" {
+    #include "DEV_Config.h"
+    #include "EPD_7in5b_V2.h"
+    #include "GUI_Paint.h"
+}
 
 // Holds last echoed line for display
 static char g_last_echo[128] = "";
 
+// e-Paper display buffers
+static UBYTE *g_epd_image = NULL;  // Black image buffer
+static UBYTE *g_epd_red = NULL;    // Red image buffer
+
+void init_epaper_display() {
+    printf("Initializing 7.5\" e-Paper display (B V2)...\r\n");
+    
+    // Initialize the hardware
+    if (DEV_Module_Init() != 0) {
+        printf("Failed to initialize e-Paper hardware!\r\n");
+        return;
+    }
+    
+    // Initialize the display
+    printf("EPD_7IN5B_V2_Init()\r\n");
+    EPD_7IN5B_V2_Init_Fast();
+    printf("EPD_7IN5B_V2_Clear()\r\n");
+    EPD_7IN5B_V2_ClearBlack();
+    DEV_Delay_ms(500);
+    
+    // Create image buffers for black and red content
+    // 7.5" display: 800x480, 8 pixels per byte, so (800/8) * 480 = 48000 bytes each
+    UWORD imagesize = (EPD_7IN5B_V2_WIDTH / 8) * EPD_7IN5B_V2_HEIGHT;
+    
+    g_epd_image = (UBYTE *)malloc(imagesize);
+    g_epd_red = (UBYTE *)malloc(imagesize);
+    
+    if (g_epd_image == NULL || g_epd_red == NULL) {
+        printf("Failed to allocate memory for e-Paper image buffers!\r\n");
+        return;
+    }
+    
+    // Initialize red buffer to all white (0xFF = no red pixels)
+    for (UWORD i = 0; i < imagesize; i++) {
+        g_epd_red[i] = 0xFF;
+    }
+    
+    // Setup paint buffer for black content
+    printf("White background\r\n");
+    Paint_NewImage(g_epd_image, EPD_7IN5B_V2_WIDTH, EPD_7IN5B_V2_HEIGHT, 0, WHITE);
+    Paint_SelectImage(g_epd_image);
+    Paint_Clear(WHITE);
+    
+    // Draw "Hello World" on the display
+    printf("Drawing\r\n");
+    Paint_DrawString_EN(10, 10, "Hello World!", &Font24, WHITE, BLACK);
+    Paint_DrawString_EN(10, 60, "7.5\" e-Paper Initialized", &Font16, WHITE, BLACK);
+    
+    // Display the image with both black and red buffers
+    printf("display text\r\n");
+    EPD_7IN5B_V2_Display(g_epd_image, g_epd_red);
+    printf("delay\r\n");
+    DEV_Delay_ms(2000);
+    
+    printf("e-Paper display ready!\r\n");
+    // EPD_7IN5B_V2_Sleep();
+}
+
+void update_epaper_display(const char *line1, const char *line2) {
+    if (g_epd_image == NULL || g_epd_red == NULL) return;
+    
+    // Clear and prepare buffers
+    UWORD imagesize = (EPD_7IN5B_V2_WIDTH / 8) * EPD_7IN5B_V2_HEIGHT;
+    for (UWORD i = 0; i < imagesize; i++) {
+        g_epd_red[i] = 0xFF;  // No red pixels
+    }
+    
+    Paint_SelectImage(g_epd_image);
+    Paint_Clear(WHITE);
+    
+    if (line1) {
+        Paint_DrawString_EN(50, 100, (char *)line1, &Font16, BLACK, WHITE);
+    }
+    if (line2) {
+        Paint_DrawString_EN(50, 150, (char *)line2, &Font16, BLACK, WHITE);
+    }
+    
+    EPD_7IN5B_V2_Display(g_epd_image, g_epd_red);
+}
+
 // Define the maximum size for the input string buffer
 #define MAX_INPUT_LEN 64
 // Define the timeout period: 5 seconds in microseconds
@@ -21,55 +111,30 @@ static char g_last_echo[128] = "";
 // ASCII code for Backspace (often sent as 0x08)
 #define ASCII_BACKSPACE 8
 
-// Helper function to handle the echoing and resetting of the buffer
+void wait_for_usb_connection(DisplayManager &display) {
-void echo_and_reset(char* buffer, int* index_ptr, DisplayManager &display) {
-    if (*index_ptr > 0) {
-        buffer[*index_ptr] = '\0';
-        // Print to USB serial (ALL CAPS)
-        printf("\nEchoed (ALL CAPS): ");
-        for (int i = 0; buffer[i] != '\0'; i++) {
-            char ch = toupper(buffer[i]);
-            printf("%c", ch);
-        }
-        printf("\n");
-
-        // Save last echoed (all caps) for display
-        size_t i = 0;
-        for (; buffer[i] != '\0' && i < sizeof(g_last_echo) - 1; ++i) {
-            g_last_echo[i] = (char)toupper(buffer[i]);
-        }
-        g_last_echo[i] = '\0';
-    }
-
-    *index_ptr = 0;
-    printf("> ");
-    // Update OLED to show cleared input and last echo
-    display.set_last_echo(g_last_echo);
-    display.refresh("", g_last_echo);
-}
-
-void wait_for_usb_connection() {
     printf("Waiting for USB host to connect...\n");
     while (!stdio_usb_connected()) {
         sleep_ms(100);
     }
     printf("\nConnection Established! Starting Echo Session...\n");
+    display.refresh(">", nullptr);
+    
+    // Initialize e-Paper display
+    init_epaper_display();
 }
 
 void run_echo_session(DisplayManager &display) {
     char input_buffer[MAX_INPUT_LEN];
     int buffer_index = 0;
-    uint64_t last_char_time = time_us_64();
 
-    printf("--- Pico USB String Echo Program Started ---\n");
+    printf("--- Welcome User! ---\n");
-    printf("Type a sentence (up to %d chars). It will echo on Enter/Timeout.\n", MAX_INPUT_LEN - 2);
+    printf("Type a command (or write help):\n");
     printf("--------------------------------------------\n");
     printf("> ");
 
     while (stdio_usb_connected()) {
         int c = getchar_timeout_us(0);
         if (c != PICO_ERROR_TIMEOUT) {
-            last_char_time = time_us_64();
             char input_char = (char)c;
             if (input_char == ASCII_BACKSPACE || input_char == 127) {
                 if (buffer_index > 0) {
@@ -80,8 +145,16 @@ void run_echo_session(DisplayManager &display) {
                     display.refresh(input_buffer, g_last_echo);
                 }
             } else if (input_char == '\r' || input_char == '\n') {
-                echo_and_reset(input_buffer, &buffer_index, display);
+                echo_and_reset(input_buffer, &buffer_index);
-                // after echo_and_reset the display is refreshed inside it
+                // Save last echoed (all caps) for display
+                size_t i = 0;
+                for (; input_buffer[i] != '\0' && i < sizeof(g_last_echo) - 1; ++i) {
+                    g_last_echo[i] = input_buffer[i];
+                }
+                g_last_echo[i] = '\0';
+                // Update OLED to show cleared input and last echo
+                display.set_last_echo(g_last_echo);
+                display.refresh("", g_last_echo);
             } else if (buffer_index < (MAX_INPUT_LEN - 1) && isprint(input_char)) {
                 printf("%c", input_char);
                 input_buffer[buffer_index] = input_char;
@@ -91,16 +164,6 @@ void run_echo_session(DisplayManager &display) {
                 display.refresh(input_buffer, g_last_echo);
             }
         }
-
-        if (buffer_index > 0 && (time_us_64() - last_char_time) > TIMEOUT_US) {
-            printf("\n--- Timeout Reached (5.0s silence) ---\n");
-            echo_and_reset(input_buffer, &buffer_index, display);
-            last_char_time = time_us_64();
-        }
-
-        // Advance marquee for last echoed text if needed
-        size_t last_len = strlen(g_last_echo);
-        uint64_t now_ms = time_us_64() / 1000;
         sleep_us(100);
     }
     
@@ -109,11 +172,14 @@ void run_echo_session(DisplayManager &display) {
 
 int main() {
     stdio_init_all();
+
+    
     DisplayManager display;
     display.init();
+    display.refresh("Waiting for USB/Serial", nullptr);
 
     while (true) {
-        wait_for_usb_connection();
+        wait_for_usb_connection(display);
         run_echo_session(display);
     }