diff options
Diffstat (limited to 'cores/arduino/wiring_pulse.c')
| -rw-r--r-- | cores/arduino/wiring_pulse.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/cores/arduino/wiring_pulse.c b/cores/arduino/wiring_pulse.c index 76383e9..3212f13 100644 --- a/cores/arduino/wiring_pulse.c +++ b/cores/arduino/wiring_pulse.c @@ -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; |