Updated with reed relais and debouncing button

include/Heartbeater.hpp

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <Arduino.h>
+
+class Heartbeater
+{   
+private:
+    int _pin;
+    uint8_t _onState;
+    uint8_t _ledState;
+    uint8_t _inBeatCount;
+    unsigned long _beatInterval;
+    unsigned long _onInterval = 30;
+    unsigned long _offInterval = 150;
+    unsigned long _inBeatInterval = 0;
+    unsigned long _lastBeat;
+    unsigned long _lastInBeat;
+    unsigned long _beatCount = 0;
+public:
+    explicit Heartbeater(const int pin, uint8_t onState = HIGH, unsigned long beatIntervalMillis = 2000UL)
+        : _pin(pin), _onState(onState), _beatInterval(beatIntervalMillis)
+    {
+        _ledState = !_onState;
+        pinMode(_pin, OUTPUT);
+    }
+
+    void loop()
+    {
+        digitalWrite(_pin, _ledState); // each iteration of loop() will set the IO pins, even if they don't change, that's okay
+
+        // Toggle back and forth between the two LEDs
+        if ((millis() - _lastBeat) >= _beatInterval)
+        {
+            // time is up!
+            _inBeatCount = 0;
+            _lastBeat += _beatInterval;
+            _beatCount++;
+        }
+
+        // Create the heartbeat effect
+        if ((millis() - _lastInBeat) >= _inBeatInterval)
+        {
+            _lastInBeat = millis();
+            if (_inBeatCount < 2)
+            {
+                _ledState = !_ledState;
+                if (_ledState == _onState) {
+                    _inBeatInterval = _onInterval;
+                }
+                else {
+                    _inBeatCount++;
+                    _inBeatInterval = _offInterval;
+                }
+            }
+        }
+    }
+};