From 886451cc929e7ca8263b82047c1af89dd5750149 Mon Sep 17 00:00:00 2001
From: Michael Mandl <mandlm@molez.net>
Date: Mon, 16 Oct 2017 16:51:08 +0200
Subject: [PATCH] Separated Qt and WiringPi code in distance thread

---
 source/CMakeLists.txt     |  5 ++-
 source/distancethread.cpp | 68 +++------------------------------------
 source/distancethread.h   | 12 +++----
 source/mainwindow.cpp     |  2 +-
 4 files changed, 13 insertions(+), 74 deletions(-)

diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
index 83bbd0f..dc0efd5 100644
--- a/source/CMakeLists.txt
+++ b/source/CMakeLists.txt
@@ -19,7 +19,10 @@ add_executable(${PROJECT_NAME}
 	led.h
 	blinkthread.cpp
     blinkthread.h
-    distancethread.cpp
+	median.h
+	hcsr04.cpp
+	hcsr04.h
+	distancethread.cpp
     distancethread.h
 )
 
diff --git a/source/distancethread.cpp b/source/distancethread.cpp
index 0df5e3d..37867b4 100644
--- a/source/distancethread.cpp
+++ b/source/distancethread.cpp
@@ -1,76 +1,16 @@
 #include "distancethread.h"
-#include <wiringPi.h>
 
-volatile unsigned int timestampHigh = 0;
-volatile unsigned int pulseLength = 0;
-
-DistanceThread::DistanceThread()
+DistanceThread::DistanceThread(unsigned int triggerPin, unsigned int echoPin)
+	: m_hcsr04(triggerPin, echoPin)
 {
-    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 if (timestampHigh != 0)
-        {
-			pulseLength = micros() - timestampHigh;
-			timestampHigh = 0;
-        }
-    });
-
     while (true)
     {
-		std::vector<double> values;
-		for (int i = 0; i < 15; ++i)
-		{
-	        digitalWrite(m_triggerPin, HIGH);
-    	    delayMicroseconds(10);
-        	digitalWrite(m_triggerPin, LOW);
-	        delayMicroseconds(40);
-
-    	    if (pulseLength < 25e3)
-        	{
-            	values.push_back(pulseLength);	
-	        }
-	  
-			delay(10);
-		}
-
-		if (!values.empty())
-		{
-			emit distanceUpdated(median(values) / 0.58);
-		}
-
-		delay(100);
+		emit distanceUpdated(m_hcsr04.getDistance());
+		msleep(100);
     }
 }
 
-template<typename VALUE_TYPE>
-double DistanceThread::median(std::vector<VALUE_TYPE> values) const
-{
-	if (values.size() == 0)
-	{
-		return 0.0;
-	}
-
-	size_t centerIndex = values.size() / 2;
-	std::nth_element(values.begin(), values.begin() + centerIndex, values.end());
-	
-	if (values.size() % 2 == 1)
-	{
-		return values[centerIndex];
-	}
-	else
-	{
-		std::nth_element(values.begin(), values.begin() + centerIndex + 1, values.end());
-		return (values[centerIndex] + values[centerIndex + 1]) / 2.0;
-	}
-}
diff --git a/source/distancethread.h b/source/distancethread.h
index f70bf0b..c73b55d 100644
--- a/source/distancethread.h
+++ b/source/distancethread.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <vector>
+#include "hcsr04.h"
 #include <QThread>
 
 class DistanceThread : public QThread
@@ -8,19 +8,15 @@ class DistanceThread : public QThread
     Q_OBJECT
 
 private:
-    const int m_triggerPin = 28;
-    const int m_echoPin = 29;
+	HCSR04 m_hcsr04;
 
 public:
-    DistanceThread();
+	DistanceThread() = delete;
+    DistanceThread(unsigned int triggerPin, unsigned int echoPin);
 
 protected:
     void run() override;
 
-private:
-	template<typename VALUE_TYPE>
-	double median(std::vector<VALUE_TYPE> values) const;
-
 signals:
     void distanceUpdated(double distMeters);
 };
diff --git a/source/mainwindow.cpp b/source/mainwindow.cpp
index 5584ab8..31aa075 100644
--- a/source/mainwindow.cpp
+++ b/source/mainwindow.cpp
@@ -19,7 +19,7 @@ MainWindow::MainWindow(QWidget *parent) :
     connect(blinkThread, &BlinkThread::ledOff, this, &MainWindow::ledOff);
     blinkThread->start();
 
-    DistanceThread *distanceThread = new DistanceThread();
+    DistanceThread *distanceThread = new DistanceThread(28, 29);
     connect(distanceThread, &DistanceThread::distanceUpdated, this, &MainWindow::distanceUpdated);
     distanceThread->start();
 }