chore: add example menu demo

include/display.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <Arduino.h>
 #include <LiquidCrystal_I2C.h>
+#include "menu.hpp"
 
 /*
  * A helper class to facilitate drawing on a HD44780 LCD display.
@@ -10,6 +11,10 @@ class Display {
     Display(uint8_t addr = 0x27, uint8_t cols = 20, uint8_t rows = 4);
 
     void begin();
+    void clear();
+    void drawMenu(Menu& menu);
+
+    LiquidCrystal_I2C& getLCD();
   private:
     LiquidCrystal_I2C lcd;
 };

include/joystick.hpp

@@ -12,13 +12,22 @@
  *  Note: The button is active LOW and requires a pull-up resistor, which can either be external (10kΩ)
  *  or the internal pull-up resistor of the microcontroller (default).
  */
+enum JoystickDirection {
+  CENTER,
+  UP,
+  DOWN,
+  LEFT,
+  RIGHT
+};
+
 class Joystick {
   public:
     Joystick();
-
     double getX() const;
     double getY() const;
     bool isPressed() const;
+
+    JoystickDirection getDirection() const;
   private:
     uint8_t vrx;
     uint8_t vry;
@@ -26,4 +35,5 @@ class Joystick {
 
     const uint8_t xOffset = 13;
     const uint8_t yOffset = 10;
+    const uint8_t deadzone = 15; // Deadzone threshold to prevent jitter around the center position
 };

include/menu.hpp

@@ -0,0 +1,22 @@
+#pragma once
+#define MENU_ITEM_COUNT 4
+#include <Arduino.h>
+#include "joystick.hpp"
+
+typedef struct {
+  String name;
+  void (*action)();
+} Item;
+
+class Menu {
+  public:
+    Menu(Item* items);
+    void updateCurrentItem(JoystickDirection& direction);
+    void execute();
+
+    Item& getItemAt(size_t index);
+    size_t getCurrentItemIndex() const;
+  private:
+    Item items[MENU_ITEM_COUNT];
+    int currentItem;
+};

src/display.cpp

@@ -8,4 +8,25 @@ void Display::begin() {
   lcd.backlight();
 }
 
+void Display::clear() {
+  lcd.clear();
+}
 
+void Display::drawMenu(Menu &menu) {
+  clear();
+  size_t currentItemIndex = menu.getCurrentItemIndex();
+  for (size_t i = 0; i < MENU_ITEM_COUNT; i++) {
+    lcd.setCursor(0, i);
+    Item& item = menu.getItemAt(i);
+
+    if (i == currentItemIndex) {
+      lcd.print("> " + item.name);
+    } else {
+      lcd.print("  " + item.name);
+    }
+  }
+}
+
+LiquidCrystal_I2C& Display::getLCD() {
+  return lcd;
+}

src/joystick.cpp

@@ -20,3 +20,22 @@ double Joystick::getY() const {
 bool Joystick::isPressed() const {
   return digitalRead(sw) == LOW;
 }
+
+// Determine the direction of the joystick based on the X and Y values, considering a deadzone to prevent jitter
+JoystickDirection Joystick::getDirection() const {
+  double x = getX();
+  double y = getY();
+
+  if (abs(x) < deadzone && abs(y) < deadzone) {
+    return CENTER;
+  } else if (y > deadzone) {
+    return UP;
+  } else if (y < -deadzone) {
+    return DOWN;
+  } else if (x > deadzone) {
+    return RIGHT;
+  } else if (x < -deadzone) {
+    return LEFT;
+  }
+  return CENTER; // Default to CENTER if no direction is detected
+}

src/main.cpp

@@ -6,6 +6,14 @@
 Joystick joystick;
 Display display;
 
+Item items[MENU_ITEM_COUNT] = {
+  {"Feed", []() { Serial.println("Feeding..."); }},
+  {"Play", []() { Serial.println("Playing..."); }},
+  {"Sleep", []() { Serial.println("Sleeping..."); }},
+  {"Clean", []() { Serial.println("Cleaning..."); }}
+};
+Menu menu(items);
+
 void setup() {
   Serial.begin(9600);
   while (!Serial) {
@@ -14,7 +22,19 @@ void setup() {
 
   display.begin();
   pinMode(LED_BUILTIN, OUTPUT);
+  display.drawMenu(menu);
 }
 
 void loop() {
+  JoystickDirection direction = joystick.getDirection();
+  if (direction != JoystickDirection::CENTER) {
+    menu.updateCurrentItem(direction);
+    display.drawMenu(menu);
+  }
+
+  if (joystick.isPressed()) {
+    menu.execute();
+  }
+
+  delay(250);
 }

src/menu.cpp

@@ -0,0 +1,34 @@
+#include "menu.hpp"
+
+Menu::Menu(Item* items) : currentItem(0) {
+  for (int i = 0; i < MENU_ITEM_COUNT; i++) {
+    this->items[i] = items[i];
+  }
+}
+
+void Menu::updateCurrentItem(JoystickDirection &direction) {
+  switch (direction) {
+    case JoystickDirection::UP:
+      currentItem = (currentItem - 1 + MENU_ITEM_COUNT) % MENU_ITEM_COUNT;
+      break;
+    case JoystickDirection::DOWN:
+      currentItem = (currentItem + 1) % MENU_ITEM_COUNT;
+      break;
+    default:
+      break;
+  }
+}
+
+void Menu::execute() {
+  if (items[currentItem].action) {
+    items[currentItem].action();
+  }
+}
+
+Item& Menu::getItemAt(size_t index) {
+  return items[index];
+}
+
+size_t Menu::getCurrentItemIndex() const {
+  return currentItem;
+}