59 lines
963 B
C++
59 lines
963 B
C++
#include "hcsr04.h"
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#include "median.h"
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#include <wiringPi.h>
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volatile unsigned int timestampHigh = 0;
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volatile unsigned int pulseLength = 0;
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HCSR04::HCSR04(unsigned int triggerPin, unsigned int echoPin)
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: m_triggerPin(triggerPin)
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, m_echoPin(echoPin)
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{
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wiringPiSetup();
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pinMode(m_triggerPin, OUTPUT);
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pinMode(m_echoPin, INPUT);
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}
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void HCSR04::run()
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{
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wiringPiISR(m_echoPin, INT_EDGE_BOTH, []
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{
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if (digitalRead(29) == HIGH)
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{
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timestampHigh = micros();
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}
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else if (timestampHigh != 0)
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{
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pulseLength = micros() - timestampHigh;
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timestampHigh = 0;
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}
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});
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}
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double HCSR04::getDistance()
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{
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std::vector<double> values;
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for (int i = 0; i < 15; ++i)
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{
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digitalWrite(m_triggerPin, HIGH);
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delayMicroseconds(10);
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digitalWrite(m_triggerPin, LOW);
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delayMicroseconds(40);
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if (pulseLength < 25e3)
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{
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values.push_back(pulseLength);
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}
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delay(10);
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}
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if (!values.empty())
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{
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return median(values) / 0.58;
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}
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return 0;
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}
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