Broken interrupt foo

src/main.cpp

@@ -9,6 +9,19 @@ static uint8_t led_duration = 4;
  */
 void configureTimer()
 {
+    // Configure Timer 0 to generate periodic interrupts
+    TCCR0A = 0;// set entire TCCR0A register to 0
+    TCCR0B = 0;// same for TCCR0B
+    TCNT0  = 0;//initialize counter value to 0
+    // set compare match register for 2khz increments
+    OCR0A = 124;// = (16*10^6) / (2000*64) - 1 (must be <256)
+    // turn on CTC mode
+    TCCR0A |= (1 << WGM01);
+    // Set CS01 and CS00 bits for 64 prescaler
+    TCCR0B |= (1 << CS01) | (1 << CS00);   
+    // enable timer compare interrupt
+    TIMSK0 |= (1 << OCIE0A);
+
     // Configure Timer 1 for PWM @ 25 kHz.
     TCCR1A = 0;   // undo the configuration done by...
     TCCR1B = 0;   // ...the Arduino core library...
@@ -64,25 +77,24 @@ void setup()
     // configure timer
     Serial.println("configure timer for 25kHz PWM...");
     configureTimer();
-
     Serial.println("fan control setup done.");
+    Serial.println("Enable interrupts...");
+    sei();
 }
 
-void loop()
-{
-    uint8_t tacho_last = 0;
-    uint8_t tacho_counter = 0;
-    uint32_t iterator = 0;
-    uint32_t period = 0;
-    uint16_t rotations = 0;
+static uint8_t tacho_last = 0;
+static uint8_t tacho_counter = 0;
+static uint32_t iterator = 0;
+static uint32_t period = 0;
+static uint16_t rotations = 0;
 
-    uint16_t led_a_period = (uint16_t)-1;
-    uint16_t led_a_counter = led_a_period;
+static uint16_t led_a_period = (uint16_t)-1;
+static uint16_t led_a_counter = led_a_period;
 
-    uint16_t led_b_period = (uint16_t)-1;
-    uint16_t led_b_counter = led_b_period;
+static uint16_t led_b_period = (uint16_t)-1;
+static uint16_t led_b_counter = led_b_period;
 
-    while (1) {
+ISR(TIMER0_COMPA_vect){
     iterator++;
 
     uint8_t tacho_current = digitalRead(7);
@@ -123,5 +135,8 @@ void loop()
     } else {
         digitalWrite(3, LOW);
     }
-    }  
+}
+
+void loop()
+{
 }