start integration of mqtt

Metro/Metro.cpp

@@ -0,0 +1,73 @@
+
+#if defined(ARDUINO) && ARDUINO >= 100
+#include "Arduino.h"
+#else
+#include "WProgram.h"
+#endif
+#include "Metro.h"
+
+
+Metro::Metro(unsigned long interval_millis)
+{
+	this->autoreset = 0;
+	interval(interval_millis);
+	reset();
+}
+
+// New creator so I can use either the original check behavior or benjamin.soelberg's
+// suggested one (see below). 
+// autoreset = 0 is benjamin.soelberg's check behavior
+// autoreset != 0 is the original behavior
+
+Metro::Metro(unsigned long interval_millis, uint8_t autoreset)
+{   
+	this->autoreset = autoreset; // Fix by Paul Bouchier
+	interval(interval_millis);
+	reset();
+}
+
+void Metro::interval(unsigned long interval_millis)
+{
+  this->interval_millis = interval_millis;
+}
+
+// Benjamin.soelberg's check behavior:
+// When a check is true, add the interval to the internal counter.
+// This should guarantee a better overall stability.
+
+// Original check behavior:
+// When a check is true, add the interval to the current millis() counter.
+// This method can add a certain offset over time.
+
+char Metro::check()
+{
+  if (millis() - this->previous_millis >= this->interval_millis) {
+    // As suggested by benjamin.soelberg@gmail.com, the following line 
+    // this->previous_millis = millis();
+    // was changed to
+    // this->previous_millis += this->interval_millis;
+    
+    // If the interval is set to 0 we revert to the original behavior
+    if (this->interval_millis <= 0 || this->autoreset ) {
+    	this->previous_millis = millis();
+	} else {
+		this->previous_millis += this->interval_millis; 
+	}
+    
+    return 1;
+  }
+  
+  
+  
+  return 0;
+
+}
+
+void Metro::reset() 
+{
+ 
+  this->previous_millis = millis();
+
+}
+
+