fix(joystick): debounce joystick button

include/constants.hpp

@@ -9,3 +9,5 @@
 
 #define ACTION_INTERVAL 60000 // 1 minute
 #define MAXIMUM_STAT 100
+
+#define DEBOUNCE_DELAY 50 // Debounce delay in milliseconds for the joystick button

include/joystick.hpp

@@ -1,5 +1,6 @@
 #pragma once
 #include <Arduino.h>
+#include "constants.hpp"
 
 /*
  * A helper class to read values from the KY-023 joystick module.
@@ -25,13 +26,24 @@ class Joystick {
     Joystick();
     double getX() const;
     double getY() const;
-    bool isPressed() const;
+    bool isPressed();
 
     JoystickDirection getDirection() const;
   private:
+    class Switch {
+      public:
+        Switch(uint8_t pin);
+        bool isPressed();
+      private:
+        uint8_t pin;
+        bool lastKnownState;
+        bool lastStableState;
+        uint64_t lastDebounceTime;
+    };
+
     uint8_t vrx;
     uint8_t vry;
-    uint8_t sw;
+    Switch sw;
 
     uint8_t xOffset;
     uint8_t yOffset;

src/joystick.cpp

@@ -1,10 +1,33 @@
 #include "joystick.hpp"
 
+Joystick::Switch::Switch(uint8_t pin) : pin(pin), lastKnownState(HIGH), lastStableState(HIGH), lastDebounceTime(0) {
+  pinMode(pin, INPUT_PULLUP); // Use internal pull-up resistor
+}
+
+bool Joystick::Switch::isPressed() {
+  bool state = digitalRead(pin);
+
+  // Check for state change and debounce
+  if (state != lastKnownState) {
+    lastDebounceTime = millis(); // Reset debounce timer
+    lastKnownState = state;
+  }
+
+  // If the state has been stable for longer than the debounce delay, update the stable state
+  if ((millis() - lastDebounceTime) > DEBOUNCE_DELAY) {
+    if (lastStableState != state) {
+      lastStableState = state; // Update stable state
+      return state == LOW; // Return true if the button is pressed (active LOW)
+    }
+  }
+
+  return false; // No change in button state
+}
+
 // Initialize the joystick pins in the constructor
-Joystick::Joystick() : vrx(A0), vry(A1), sw(4) {
+Joystick::Joystick() : vrx(A0), vry(A1), sw(Switch(4)) {
   pinMode(vrx, INPUT);
   pinMode(vry, INPUT);
-  pinMode(sw, INPUT_PULLUP);
 
   // Calibrate the joystick by reading the center position and storing it as an offset
   xOffset = map(analogRead(vrx), 0, 1023, -100, 100);
@@ -21,8 +44,8 @@ double Joystick::getY() const {
 }
 
 // Check if the joystick button is pressed (active LOW)
-bool Joystick::isPressed() const {
-  return digitalRead(sw) == LOW;
+bool Joystick::isPressed() {
+  return sw.isPressed();
 }
 
 // Determine the direction of the joystick based on the X and Y values, considering a deadzone to prevent jitter