  * 
  */
 volatile uint16_t clock_stretch;
-volatile boolean firstcall5;
+volatile boolean firstcall;
 
 ISR(TIMER5_COMPC_vect) {
-  if (firstcall5) {
-    firstcall5 = false;
+  if (firstcall) {
+    firstcall = false;
     return;
   }
   // compare match interrupt service routine (Timer 5 C)

}

// For Time Lapse
// generating periodic TRIG by using Timer3 Compare Match C interrupt

volatile int8_t lapse = -1;


  TCCR5A |= _BV(COM5B1); // connect OC5B pin (the internal OC5B register is LOW)

  // * the first compare match interrupt call is bogus.
  firstcall = true;
  
  if (stretch != 0) {
    // number of ticks the last HSYNC before VSYNC longer than others
