SAM: fix pulseInLong timeout using micros()

Author: facchinm

Diff for: cores/arduino/wiring_pulse.cpp

@@ -69,24 +69,22 @@ uint32_t pulseInLong(uint8_t pin, uint8_t state, unsigned long timeout)
 	uint32_t bit = p.ulPin;
 	uint32_t stateMask = state ? bit : 0;
 
-	// convert the timeout from microseconds to a number of times through
-	// the initial loop; it takes 18 clock cycles per iteration.
-	unsigned long maxloops = microsecondsToClockCycles(timeout) / 10;
+	unsigned long maxMicros = micros() + timeout;
 
 	// wait for any previous pulse to end
 	while ((p.pPort->PIO_PDSR & bit) == stateMask)
-		if (--maxloops == 0)
+		if (micros() > maxMicros)
 			return 0;
 
 	// wait for the pulse to start
 	while ((p.pPort->PIO_PDSR & bit) != stateMask)
-		if (--maxloops == 0)
+		if (micros() > maxMicros)
 			return 0;
 
 	unsigned long start = micros();
 	// wait for the pulse to stop
 	while ((p.pPort->PIO_PDSR & bit) == stateMask) {
-		if (--maxloops == 0)
+		if (micros() > maxMicros)
 			return 0;
 	}
 	return micros() - start;