Create library for software timers and enable it

ptimer.c

@@ -0,0 +1,23 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include "ptimer.h"
+
+volatile uint16_t timers[TIMERS_COUNT];
+
+void ptimer_init(void)
+{
+  for(uint8_t i=0; i<TIMERS_COUNT; ++i) timers[i] = 0;
+
+  TCCR2 |= (1<<WGM21); // CTC Mode
+	TCCR2 |= (1<<CS22) | (1<<CS21) | (1<<CS20); // Prescaler 1024
+	OCR2 = 78; // ~100Hz
+	TIMSK |= (1<<OCIE2); // Enable CTC interruptions
+}
+
+ISR(TIMER2_COMP_vect)
+{
+  for(uint8_t i=0; i<TIMERS_COUNT; ++i)
+  {
+    if(timers[i]) --timers[i];
+  }  
+}