Complete rewrite of Application

Button.cpp

@@ -0,0 +1,62 @@
+#include "Button.h"
+
+Button::Button(uint8_t pin)
+  : pin(pin),
+    stableState(HIGH),
+    lastReading(HIGH),
+    prevStableState(HIGH),
+    lastDebounceTime(0),
+    pressStart(0) {}
+
+void Button::begin() {
+  pinMode(pin, INPUT_PULLUP);
+
+  stableState = digitalRead(pin);
+  lastReading = stableState;
+  prevStableState = stableState;
+
+  lastDebounceTime = millis();
+
+  if (stableState == LOW) {
+    pressStart = millis();
+  }
+}
+
+void Button::update(unsigned long now) {
+  prevStableState = stableState;
+
+  bool reading = digitalRead(pin);
+
+  if (reading != lastReading) {
+    lastDebounceTime = now;
+    lastReading = reading;
+  }
+
+  if ((now - lastDebounceTime) > debounceDelay) {
+    if (stableState != reading) {
+      stableState = reading;
+
+      // Button just became pressed (active LOW)
+      if (stableState == LOW) {
+        pressStart = now;
+      }
+    }
+  }
+}
+
+bool Button::pressed() {
+  return (prevStableState == HIGH && stableState == LOW);
+}
+
+bool Button::released() {
+  return (prevStableState == LOW && stableState == HIGH);
+}
+
+bool Button::isDown() {
+  return stableState == LOW;
+}
+
+bool Button::held(unsigned long ms) {
+  if (!isDown()) return false;
+  return (millis() - pressStart >= ms);
+}