docs: add SSD1306 display to bill of materials

README.md

@@ -5,6 +5,7 @@ An open-source implementation of the Tamagotchi virtual pet game, designed to ru
 ## Bill of Materials
 - Arduino Nano (ATmega328P)
 - KY-023 Joystick Module
+- SSD1306 OLED Display (128x64)
 
 ## Development
 After cloning the repository, navigate to the project directory and run `make build` to compile the code. To upload the compiled firmware to your Arduino Nano, use `make upload`.

include/display.hpp

@@ -0,0 +1,16 @@
+#pragma once
+#include <Arduino.h>
+#include <U8g2lib.h>
+
+/*
+ * A helper class to facilitate drawing on the SSD1306 OLED display using the U8g2 library.
+ */
+class Display {
+  public:
+    Display();
+
+    bool begin();
+    void drawJoystick(double x, double y, bool pressed);
+  private:
+    U8G2_SSD1306_128X64_NONAME_F_HW_I2C oled;
+};

platformio.ini

@@ -19,3 +19,4 @@ monitor_speed = 9600
 ; External libraries
 lib_deps =
     embeddedartistry/LibPrintf@1.2.13
+    olikraus/U8g2@2.36.18

src/display.cpp

@@ -0,0 +1,34 @@
+#include "display.hpp"
+
+// Initialize the OLED display with the appropriate settings for the SSD1306 128x64 display utilizing hardware I2C.
+// The constructor initializes the U8g2 library with the correct parameters for the display and communication method.
+Display::Display() : oled(U8G2_R0, U8X8_PIN_NONE) {}
+
+// Try to initialize the OLED display. If initialization fails, print an error message to the serial console and return false.
+// Otherwise, set the default font and return true.
+bool Display::begin() {
+  if (!oled.begin()) {
+    Serial.println("Failed to initialize OLED display");
+    return false;
+  }
+
+  oled.setFont(u8g2_font_profont22_mn);
+  return true;
+}
+
+// TODO: Remove this method in the future
+void Display::drawJoystick(double x, double y, bool pressed) {
+  oled.clearBuffer();
+
+  // Map the joystick values from -100 to 100 to the display coordinates (0 to 128 for X and 0 to 64 for Y)
+  int16_t centerX = oled.getWidth() / 2;
+  int16_t centerY = oled.getHeight() / 2;
+  int16_t posX = map(x, -100, 100, centerX - 50, centerX + 50);
+  int16_t posY = map(y, -100, 100, centerY + 50, centerY - 50); // Invert Y-axis for display
+
+  // Draw the joystick position as a filled circle
+  oled.setDrawColor(1); // Set color to white
+  oled.drawCircle(posX, posY, pressed ? 10 : 5); // Larger circle if pressed
+
+  oled.sendBuffer();
+}

src/main.cpp

@@ -1,8 +1,10 @@
 #include <Arduino.h>
 #include <LibPrintf.h>
 #include "joystick.hpp"
+#include "display.hpp"
 
 Joystick joystick;
+Display display;
 
 void setup() {
   Serial.begin(9600);
@@ -10,8 +12,14 @@ void setup() {
     delay(10);
   }
 
+  // In case of OLED initialization failure, enter infinite loop
+  if (!display.begin()) {
+    while (true) {
+      delay(1000);
+    }
+  }
+
   pinMode(LED_BUILTIN, OUTPUT);
-  Serial.println("configured");
 }
 
 void loop() {
@@ -20,6 +28,7 @@ void loop() {
   bool pressed = joystick.isPressed();
 
   printf("X: %.2f | Y: %.2f | Pressed: %s\n", x, y, pressed ? "Yes" : "No");
+  display.drawJoystick(x, y, pressed);
 
   digitalWrite(LED_BUILTIN, pressed ? HIGH : LOW);