initial commit

millis.c

@@ -0,0 +1,20 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include "millis.h"
+
+volatile unsigned long _millis; // for millis tick !! Overflow every ~49.7 days
+
+ISR (TIMER0_COMPA_vect)
+{
+	_millis++; // INC millis tick
+}
+
+unsigned long millis(void)
+{
+	unsigned long i;
+	cli();
+	// Atomic tick reading
+	i = _millis;
+	sei();
+	return i;
+}