Change Display handler to also use widely used Adafruit library

Software/platformio.ini

@@ -15,12 +15,11 @@ framework = arduino
 monitor_speed = 115200
 lib_deps = 
 	knolleary/PubSubClient@^2.8
-	thingpulse/ESP8266 and ESP32 OLED driver for SSD1306 displays@^4.3.0
-	miguelbalboa/MFRC522@^1.4.10
 	thijse/ArduinoLog@^1.1.1
 	uipethernet/UIPEthernet@^2.0.12
 	bblanchon/ArduinoJson@^6.19.4
 	mbed-feb11/Crypto@0.0.0+sha.f04410cef037
 	adafruit/Adafruit PN532@^1.3.3
+	adafruit/Adafruit SSD1306@^2.5.13
 build_flags = 
 	-D PN532_I2C_ADDRESS=0x24

Software/src/Display.cpp

@@ -1,28 +1,49 @@
-#include <Display.h>
+#include "Display.h"
-#include <SSD1306Wire.h>
+#include <Wire.h>
+#include <stdio.h>
+#include <string.h>
 
+// Constructor: initializes I2C, creates the display object,
+// initializes the display, clears it, and sets an initial rotation.
 Display::Display(int sda, int scl, int readerid)
 {
     this->readerid = readerid;
-    display = new SSD1306Wire(0x3c, sda, scl);
-    display->init();
-    display->setTextAlignment(TEXT_ALIGN_CENTER);
-    display->flipScreenVertically();
 
+    // Initialize I2C with custom SDA and SCL pins.
+    Wire.begin(sda, scl);
+
+    // Create display object (128x64) using I2C and default I2C address 0x3C.
+    display = new Adafruit_SSD1306(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
+    if (!display->begin(SSD1306_SWITCHCAPVCC, 0x3C))
+    {
+        Serial.println("SSD1306 allocation failed");
+        while (1)
+        {
+            yield(); // Infinite loop if display initialization fails
+        }
+    }
+    display->clearDisplay();
+
+    // Flip the display vertically (if needed)
+    display->setRotation(0);
+
+    // Initialize text buffers.
     ReaderInfo[0] = '\0';      // Empty string
-    strcpy(Title, "Boot ..."); // Set initial title
+    strcpy(Title, "Boot ..."); // Initial title
     Info[0] = '\0';            // Empty string
 }
 
 void Display::clearReaderInfo()
 {
     char buffer[DISPLAY_BUFFER_SIZE];
+    // Format the reader id as a 5-digit number.
     sprintf(buffer, "%05d", readerid);
     writeReaderInfo(buffer);
 }
 
 void Display::createReaderInfo(const char *state)
 {
+    // Ensure there is enough room in the buffer (6 extra chars for the readerid)
     if (strlen(state) < DISPLAY_BUFFER_SIZE - 1 - 6)
     {
         char buffer[DISPLAY_BUFFER_SIZE];
@@ -55,50 +76,71 @@ void Display::writeInfo(const char *text)
     {
         strcpy(Info, text);
     }
-
     updateDisplay();
 }
 
+// Helper: Draws the given text centered horizontally at vertical position y.
+void Display::drawCenteredText(const char *text, int y)
+{
+    int16_t x1, y1;
+    uint16_t w, h;
+    // Get the bounding box of the text.
+    display->getTextBounds(text, 0, y, &x1, &y1, &w, &h);
+    int x = (SCREEN_WIDTH - w) / 2;
+    display->setCursor(x, y);
+    display->print(text);
+}
+
 void Display::updateDisplay()
 {
-    display->clear();
+    display->clearDisplay();
 
-    display->setFont(ArialMT_Plain_10);
+    // Draw ReaderInfo (using text size 1)
-    display->drawString(64, 0, ReaderInfo);
+    display->setTextSize(1);
+    display->setTextColor(SSD1306_WHITE);
+    drawCenteredText(ReaderInfo, 0);
 
-    display->setFont(ArialMT_Plain_24);
+    // Draw Title (using text size 2 for emphasis)
-    display->drawString(64, 13, Title);
+    display->setTextSize(2);
+    // The y-coordinate is chosen to leave room for the first line.
+    drawCenteredText(Title, 16);
 
-    display->setFont(ArialMT_Plain_16);
+    // Draw Info (using text size 1)
-    display->drawString(64, 40, Info);
+    display->setTextSize(1);
+    drawCenteredText(Info, 40);
 
     display->display();
 }
 
 void Display::updateByMQTT(const char *topic, byte *payload, unsigned int length)
 {
-    char topic_displayTitle[] = "fabreader/00000/display/title";
+    // Build expected MQTT topics for title, info, and stopping OTA.
-    sprintf(topic_displayTitle, "fabreader/%05d/display/title", readerid);
+    char topic_displayTitle[32];
+    snprintf(topic_displayTitle, sizeof(topic_displayTitle), "fabreader/%05d/display/title", readerid);
 
-    char topic_displayInfo[] = "fabreader/00000/display/info";
+    char topic_displayInfo[32];
-    sprintf(topic_displayInfo, "fabreader/%05d/display/info", readerid);
+    snprintf(topic_displayInfo, sizeof(topic_displayInfo), "fabreader/%05d/display/info", readerid);
 
-    char topic_stopOTA[] = "fabreader/00000/stopOTA";
+    char topic_stopOTA[32];
-    sprintf(topic_stopOTA, "fabreader/%05d/stopOTA", readerid);
+    snprintf(topic_stopOTA, sizeof(topic_stopOTA), "fabreader/%05d/stopOTA", readerid);
 
+    // Copy the payload into a null-terminated string.
     char *buffer = new char[length + 1];
     memcpy(buffer, payload, length);
+    buffer[length] = '\0';
 
-    if (!strcmp(topic, topic_displayTitle))
+    // Update display based on the topic.
+    if (strcmp(topic, topic_displayTitle) == 0)
     {
         writeTitle(buffer);
     }
-    else if (!strcmp(topic, topic_displayInfo))
+    else if (strcmp(topic, topic_displayInfo) == 0)
     {
         writeInfo(buffer);
     }
-    else if (!strcmp(topic, topic_stopOTA))
+    else if (strcmp(topic, topic_stopOTA) == 0)
     {
         clearReaderInfo();
     }
+    delete[] buffer;
 }

Software/src/Display.h

@@ -1,20 +1,32 @@
 #ifndef DISPLAY_H
 #define DISPLAY_H
-#include <SSD1306Wire.h>
+
+#include <Adafruit_GFX.h>
+#include <Adafruit_SSD1306.h>
 
 #define DISPLAY_BUFFER_SIZE 30
 
+#define SCREEN_WIDTH 128
+#define SCREEN_HEIGHT 64
+#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset)
+
 class Display
 {
 private:
-    SSD1306Wire *display;
+    Adafruit_SSD1306 *display;
     int readerid;
     char ReaderInfo[DISPLAY_BUFFER_SIZE];
     char Title[DISPLAY_BUFFER_SIZE];
     char Info[DISPLAY_BUFFER_SIZE];
 
+    // Helper function to center text horizontally at a given y coordinate.
+    void drawCenteredText(const char *text, int y);
+
 public:
+    // The constructor takes the SDA and SCL pins (which are used to initialize Wire)
+    // and the reader ID.
     Display(int sda, int scl, int readerid);
+
     void createReaderInfo(const char *state);
     void clearReaderInfo();
     void writeReaderInfo(const char *text);
@@ -23,4 +35,5 @@ public:
     void updateDisplay();
     void updateByMQTT(const char *topic, byte *payload, unsigned int length);
 };
+
 #endif