+/*--------------------------------------------------------------------------*/
+
+void setup_timer(void)
+{
+ PRR1 &= ~_BV(PRTIM4);
+ OCR4A = F_CPU / 1000 - 1; /* Timer4: 1000Hz interval */
+ TCCR4B = (0b00<<WGM42)|(0b001<<CS40); /* Normal Mode, Prescaler 1 */
+ TIMSK4 = _BV(OCIE4A); /* Enable Output Compare A interrupt */
+}