diff --git a/avdweb_Switch.cpp b/avdweb_Switch.cpp
index c5fd143..0764fe5 100644
--- a/avdweb_Switch.cpp
+++ b/avdweb_Switch.cpp
@@ -112,12 +112,11 @@ WEBSITE: http://www.avdweb.nl/arduino/hardware-interfacing/simple-switch-debounc
 #include "Arduino.h"
 #include "avdweb_Switch.h"
 
-switchCallback_t Switch::_beepAllCallback; // definition static function pointer with typedef
-//void (*Switch::_beepAllCallback)(void*); // definition static function pointer without typedef
-void* Switch::_beepAllCallbackParam; // without = 
+switchCallback_t Switch::_beepAllCallback = nullptr; // definition static function pointer with typedef
+void* Switch::_beepAllCallbackParam = nullptr;
 
-Switch::Switch(byte _pin, byte PinMode, bool polarity, int debouncePeriod, int longPressPeriod, int doubleClickPeriod, int deglitchPeriod):
-pin(_pin), polarity(polarity), deglitchPeriod(deglitchPeriod), debouncePeriod(debouncePeriod), longPressPeriod(longPressPeriod), doubleClickPeriod(doubleClickPeriod)
+Switch::Switch(byte _pin, byte PinMode, bool polarity, unsigned long debouncePeriod, unsigned long longPressPeriod, unsigned long doubleClickPeriod, unsigned long deglitchPeriod):
+deglitchPeriod(deglitchPeriod), debouncePeriod(debouncePeriod), longPressPeriod(longPressPeriod), doubleClickPeriod(doubleClickPeriod), pin(_pin), polarity(polarity)
 { pinMode(pin, PinMode);
   switchedTime = millis();
   debounced = digitalRead(pin);
diff --git a/avdweb_Switch.h b/avdweb_Switch.h
index 42eb267..9c21f74 100644
--- a/avdweb_Switch.h
+++ b/avdweb_Switch.h
@@ -18,7 +18,7 @@ typedef void (*switchCallback_t)(void*);
 class Switch
 {
 public:	
-  Switch(byte _pin, byte PinMode=INPUT_PULLUP, bool polarity=LOW, int debouncePeriod=50, int longPressPeriod=300, int doubleClickPeriod=250, int deglitchPeriod=10);
+  Switch(byte _pin, byte PinMode=INPUT_PULLUP, bool polarity=LOW, unsigned long debouncePeriod=50, unsigned long longPressPeriod=300, unsigned long doubleClickPeriod=250, unsigned long deglitchPeriod=10);
   bool poll(); // Returns 1 if switched
   bool switched(); // will be refreshed by poll()
   bool on();
@@ -36,7 +36,7 @@ class Switch
   void setSingleClickCallback(switchCallback_t cb, void* param = nullptr);
   void setBeepAllCallback(switchCallback_t cb, void* param = nullptr); 
 
-  int deglitchPeriod, debouncePeriod, longPressPeriod, doubleClickPeriod;
+  unsigned long deglitchPeriod, debouncePeriod, longPressPeriod, doubleClickPeriod;
 
   protected:
   bool process(); // not inline, used in child class
@@ -58,14 +58,13 @@ class Switch
   switchCallback_t _longPressCallback = nullptr;
   switchCallback_t _doubleClickCallback = nullptr;
   switchCallback_t _singleClickCallback = nullptr;
-  static switchCallback_t _beepAllCallback = nullptr; // static function pointer, can be used by all objects
-  //static void(*_beepAllCallback)(void*) = nullptr; // static function pointer without typedef
+  static switchCallback_t _beepAllCallback; // static function pointer, can be used by all objects
   
   void* _pushedCallbackParam = nullptr;
   void* _releasedCallbackParam = nullptr;
   void* _longPressCallbackParam = nullptr;
   void* _doubleClickCallbackParam = nullptr;
   void* _singleClickCallbackParam = nullptr;
-  static void* _beepAllCallbackParam = nullptr; // can be used by all objects
+  static void* _beepAllCallbackParam; // can be used by all objects
 };
 #endif