超声波传感器HC-SR04和Arduino设备的Sonar系统项目

这是一个使用Ultrasonic HC-SR04设备和Arduino(Arduino UNO)构建声纳系统的物联网项目。声纳系统检测到其范围内的物体(角度和距离)并在笔记本电脑(监视器)屏幕上显示其外观。声纳使用声波的回声原理通过物体。

硬件要求

• Arduino UNO主板
• 用于Arduino UNO的USB电缆连接器
• Ultra Sonic HC-SR04
• 跳线电线(公母线)
• 微服务器SG90

软件要求

• Arduino软件
• Processing软件

声纳系统的工作原理

Ultra Sonic HC-SR04以40,000Hz的频率发射超声波，在空中传播。如果路径中有物体或障碍物，则声波会与物体碰撞并弹回Ultra Sonic模块。对象的角度和距离显示在屏幕上(监视器)。

在这个项目中，我们使用处理应用程序来显示声纳范围。

在为Sonar系统编写程序之前，首先要通过超声波传感器HC-SR04和Arduino进行距离计算，这里要了解超声波设备的工作原理。

编写Arduino程序，使用Ultra Sonic HC-SR04测量距离并旋转伺服电机。示例代码如下：

#include <Servo.h>  
const int trigPin = 8;  
const int echoPin = 9;  
long duration; //declare time duration  
int distance;  //declare distance  
Servo myServo; // Object servo  

void setup() {  
  pinMode(trigPin, OUTPUT); // trigPin as an output  
  pinMode(echoPin, INPUT); // echoPin as an input  
  Serial.begin(9600);  
  myServo.attach(10); // pin connected to Servo  
}  

void loop() {  
  // rotating servo i++ depicts increment of one degree  
  for(int i=0;i<=180;i++){    
  myServo.write(i);  
  delay(30);  
  distance = calculateDistance();  
  Serial.print(i);   
  Serial.print(",");   
  Serial.print(distance);   
  Serial.print(".");  
  }  
  // Repeats the previous lines from 180 to 0 degrees  
  for(int i=180;i>0;i--){    
  myServo.write(i);  
  delay(30);  
  distance = calculateDistance();  
  Serial.print(i);  
  Serial.print(",");  
  Serial.print(distance);  
  Serial.print(".");  
  }  
}  

int calculateDistance(){   
  digitalWrite(trigPin, LOW);   
  delayMicroseconds(2);  
  // Sets the trigPin on HIGH state for 10 micro seconds  
  digitalWrite(trigPin, HIGH);   
  delayMicroseconds(10);  
  digitalWrite(trigPin, LOW);  
  duration = pulseIn(echoPin, HIGH);   
  distance= duration*0.034/2;  
  return distance;  
}

编译上面代码，如下所示：

现在，使用Arduino USB连接器将Arduino设备连接到个人计算机并上传程序。

数字电路图

Ultrasonic Sensor HC-SR04           Arduino UNO
VCC    -------------------------------->    5v
Trig    -------------------------------->    Pin 8
Echo    -------------------------------->    Pin 9
GND    -------------------------------->    GND

Micro Servo Motor SG90           Arduino UNO
Orange wire    ---------------------->    Pin 10
Red wire     ---------------------->      3.3v
Brown wire    ---------------------->    GND

现在，将风扇的较大部分放在伺服电机的旋转轮上。将超声波设备放在伺服电机上使其旋转(可以使用双面胶带)。

在Processing IDE中测试以下代码并运行它。处理IDE显示物体进入超声波设备范围时的角度距离。

import processing.serial.*;  
import java.awt.event.KeyEvent;  
import java.io.IOException;  
Serial myPort;// defubes variables  
String angle="";  
String distance="";  
String data="";  
String noObject;  
float pixsDistance;  
int iAngle, iDistance;  
int index1=0;  
int index2=0;  
PFont orcFont;  
void setup() {  
  size (1366, 768);  
  smooth();  
  myPort = new Serial(this,"COM3", 9600); // change this accordingly  
  myPort.bufferUntil('.'); // reads the data from the serial port up to the character ?.?. So actually it reads this: angle,distance.  
}  
void draw() {  
  fill(98,245,31);  
  // simulating motion blur and slow fade of the moving line  
  noStroke();  
  fill(0,4);  
  rect(0, 0, width, height-height*0.065);  
  fill(98,245,31); // green color  
  // calls the functions for drawing the radar  
  drawRadar();  
  drawLine();  
  drawObject();  
  drawText();  
}  
void serialEvent (Serial myPort) { // starts reading data from the Serial Port  
// reads the data from the Serial Port up to the character ?.? and puts it into the String variable ?data?.  
  data = myPort.readStringUntil('.');  
  data = data.substring(0,data.length()-1);  
  index1 = data.indexOf(","); // find the character ?,? and puts it into the variable ?index1?  
  angle= data.substring(0, index1); // read the data from position ?0? to position of the variable index1 or thats the value of the angle the Arduino Board sent into the Serial Port  
  distance= data.substring(index1+1, data.length()); // read the data from position ?index1? to the end of the data pr thats the value of the distance  
  // converts the String variables into Integer  
  iAngle = int(angle);  
  iDistance = int(distance);  
}  
void drawRadar() {  
  pushMatrix();  
  translate(width/2,height-height*0.074); // moves the starting coordinats to new location  
  noFill();  
  strokeWeight(2);  
  stroke(98,245,31);  
  // draws the arc lines  
  arc(0,0,(width-width*0.0625),(width-width*0.0625),PI,TWO_PI);  
  arc(0,0,(width-width*0.27),(width-width*0.27),PI,TWO_PI);  
  arc(0,0,(width-width*0.479),(width-width*0.479),PI,TWO_PI);  
  arc(0,0,(width-width*0.687),(width-width*0.687),PI,TWO_PI);  
  // draws the angle lines  
  line(-width/2,0,width/2,0);  
  line(0,0,(-width/2)*cos(radians(30)),(-width/2)*sin(radians(30)));  
  line(0,0,(-width/2)*cos(radians(60)),(-width/2)*sin(radians(60)));  
  line(0,0,(-width/2)*cos(radians(90)),(-width/2)*sin(radians(90)));  
  line(0,0,(-width/2)*cos(radians(120)),(-width/2)*sin(radians(120)));  
  line(0,0,(-width/2)*cos(radians(150)),(-width/2)*sin(radians(150)));  
  line((-width/2)*cos(radians(30)),0,width/2,0);  
  popMatrix();  
}  
void drawObject() {  
  pushMatrix();  
  translate(width/2,height-height*0.074); // moves the starting coordinats to new location  
  strokeWeight(9);  
  stroke(255,10,10); // red color  
  pixsDistance = iDistance*((height-height*0.1666)*0.025); // covers the distance from the sensor from cm to pixels  
  // limiting the range to 40 cms  
  if(iDistance<40){  
    // draws the object according to the angle and the distance  
    line(pixsDistance*cos(radians(iAngle)),-pixsDistance*sin(radians(iAngle)),(width-width*0.505)*cos(radians(iAngle)),-(width-width*0.505)*sin(radians(iAngle)));  
  }  
  popMatrix();  
}  
void drawLine() {  
  pushMatrix();  
  strokeWeight(9);  
  stroke(30,250,60);  
  translate(width/2,height-height*0.074); // moves the starting coordinats to new location  
  line(0,0,(height-height*0.12)*cos(radians(iAngle)),-(height-height*0.12)*sin(radians(iAngle))); // draws the line according to the angle  
  popMatrix();  
}  
void drawText() { // draws the texts on the screen  
  pushMatrix();  
  if(iDistance>40) {  
    noObject = "Out of Range";  
  }  
  else {  
    noObject = "In Range";  
  }  
  fill(0,0,0);  
  noStroke();  
  rect(0, height-height*0.0648, width, height);  
  fill(98,245,31);  
  textSize(25);  
  text("10cm",width-width*0.3854,height-height*0.0833);  
  text("20cm",width-width*0.281,height-height*0.0833);  
  text("30cm",width-width*0.177,height-height*0.0833);  
  text("40cm",width-width*0.0729,height-height*0.0833);  
  textSize(40);  
  text("Angle: " + iAngle +" ?", width-width*0.78, height-height*0.0277);  
  text("Distance: ", width-width*0.36, height-height*0.0277);  
  if(iDistance<40) {  
    text(" " + iDistance +" cm", width-width*0.225, height-height*0.0277);  
  }  
  textSize(25);  
  fill(98,245,60);  
  translate((width-width*0.4994)+width/2*cos(radians(30)),(height-height*0.0907)-width/2*sin(radians(30)));  
  rotate(-radians(-60));  
  text("30?",0,0);  
  resetMatrix();  
  translate((width-width*0.503)+width/2*cos(radians(60)),(height-height*0.0888)-width/2*sin(radians(60)));  
  rotate(-radians(-30));  
  text("60?",0,0);  
  resetMatrix();  
  translate((width-width*0.507)+width/2*cos(radians(90)),(height-height*0.0833)-width/2*sin(radians(90)));  
  rotate(radians(0));  
  text("90?",0,0);  
  resetMatrix();  
  translate(width-width*0.513+width/2*cos(radians(120)),(height-height*0.07129)-width/2*sin(radians(120)));  
  rotate(radians(-30));  
  text("120?",0,0);  
  resetMatrix();  
  translate((width-width*0.5104)+width/2*cos(radians(150)),(height-height*0.0574)-width/2*sin(radians(150)));  
  rotate(radians(-60));  
  text("150?",0,0);  
  popMatrix();  
}

现在，运行 processing 应用程序并将对象(笔)放在超声波设备前面。当伺服电机旋转且物体进入超声波装置范围内时，物体的外观就会出现在显示屏上。物体的存在用红色标记标记，如果超声波设备处理应用范围内没有物体，则显示绿色标记。