qEcho/source/distancethread.cpp

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2017-10-15 10:30:15 +00:00
#include "distancethread.h"
#include <wiringPi.h>
volatile unsigned int timestampHigh = 0;
volatile unsigned int timestampLow = 0;
DistanceThread::DistanceThread()
{
wiringPiSetup();
pinMode(m_triggerPin, OUTPUT);
pinMode(m_echoPin, INPUT);
}
void DistanceThread::run()
{
wiringPiISR(m_echoPin, INT_EDGE_BOTH, []
{
if (digitalRead(29) == HIGH)
{
timestampHigh = micros();
}
else
{
timestampLow = micros();
}
});
while (true)
{
digitalWrite(m_triggerPin, HIGH);
delayMicroseconds(10);
digitalWrite(m_triggerPin, LOW);
delayMicroseconds(40);
unsigned int delayUS = timestampLow - timestampHigh;
if (delayUS < 25e3)
{
emit distanceUpdated(delayUS / 0.58);
}
delay(100);
}
}