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Code Issues Releases Activity

pulseInLong: fix incorrect timeout handling

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This commit is contained in:
Martino Facchin 2015-09-21 10:24:48 +02:00
parent 1390019d23
commit c7b27431a9
1 changed files with 4 additions and 7 deletions
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11
hardware/arduino/avr/cores/arduino/wiring_pulse.c
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@ -69,25 +69,22 @@ unsigned long pulseInLong(uint8_t pin, uint8_t state, unsigned long timeout)
uint8_t port = digitalPinToPort(pin);
uint8_t stateMask = (state ? bit : 0);
// convert the timeout from microseconds to a number of times through
// the initial loop; it takes 16 clock cycles per iteration.
unsigned long numloops = 0;
unsigned long maxloops = microsecondsToClockCycles(timeout);
unsigned long maxMicros = micros() + timeout;
// wait for any previous pulse to end
while ((*portInputRegister(port) & bit) == stateMask)
if (numloops++ == maxloops)
if (micros() > maxMicros)
return 0;
// wait for the pulse to start
while ((*portInputRegister(port) & bit) != stateMask)
if (numloops++ == maxloops)
if (micros() > maxMicros)
return 0;
unsigned long start = micros();
// wait for the pulse to stop
while ((*portInputRegister(port) & bit) == stateMask) {
if (numloops++ == maxloops)
if (micros() > maxMicros)
return 0;
}
return micros() - start;