Arduino Basics: HC-SR04
Showing posts with label HC-SR04. Show all posts
Showing posts with label HC-SR04. Show all posts

13 March 2017

Prextron CHAIN BLOCKS - Arduino Nano controlled Ultrasonic sensor that switches a motor wirelessly using 433MHz RF modules and a relay board.


 

Description

In this tutorial, I will be evaluating Prextron CHAIN blocks – a new system that allows you to connect your sensors and actuators to an Arduino NANO using clever 3D-printed prototyping boards that can be stacked sideways. This very modular system makes it easy to connect, disconnect and replace project components, and eliminate the “rats nest of wires” common to many advanced Arduino projects. CHAIN BLOCKS are open, which means that you can incorporate any of your sensors or actuators to these prototyping boards, and you can decide which specific pin on Arduino you plan to use. The CHAIN BLOCK connections prevent or reduce common connection mistakes, which make them ideal for class-room projects and learning activities.

I am going to set up a project to put these CHAIN BLOCKs to the test:
When I place my hand in-front of an Ultrasonic sensor, the Arduino will transmit a signal wirelessly to another Arduino, and consequently turn on a motor.


 

Parts Required:

You need the following Prextron Chain Blocks


Please note: You may need to solder the module wires to the CHAIN BLOCK protoboard.


 
 

Arduino Libraries and IDE

This project does not use any libraries. However, you will need to upload Arduino code to the Arduino. For this you will need the Arduino IDE which can be obtained from the official Arduino website:
https://www.arduino.cc/en/main/software


 
 

ARDUINO CODE: RF Transmitter


 
 

ARDUINO CODE: RF Receiver


 
 

Fritzing diagrams for Transmitter


 


 


 


 

 

Fritzing diagrams for Receiver


 


 


 


 

Concluding comments

The purpose of this project was to evaluate Prextron CHAIN BLOCKs and put them to the test. Here is what I thought of CHAIN BLOCKS at the time of evaluation. Some of my points mentioned below may no longer apply to the current product. It may have evolved / improved since then. So please take that into consideration


 

What I liked about Chain Blocks

  • The design is simple, the product is simple.
  • Once the Chain Blocks were all assembled, they were very easy to connect to each other.
  • I can really see the benefit of Chain Blocks in a teaching environment, because it simplifies the connection process, and reduces connection mixups.
  • It was good to see that the blocks come in different colours, which means that you can set up different colour schemes for different types of modules.
  • You can incorporate pretty much any sensor or Actuator into the Chain block which is very appealing.
  • You also have the flexibility of choosing which pins you plan to use on the Arduino.
  • Projects look a lot neater, because you no longer have the rats nest of wires.
  • The Blocks lock into each other which means that they are much easier to transport/carry.


 

What I did not like about Chain Blocks

  • In most cases, the Chain Block protoboard lanes were not numbered, which increased the chances of making mistakes when soldering
  • The need to solder modules to the protoboard, may be a discouragement for some people.
  • I would have liked a choice of different size Chain blocks. Some of the sensors did not fit nicely into the Square blocks.
  • Prextron really need to work on their website if they plan to get serious with this product: Webpage has incomplete functionality or irrelevant links etc etc.


 
 
 

Thank you very much to Prextron for providing the CHAIN BLOCKS used in this tutorial, and allowing me to try out their product. If you are interested in trying them yourself, then make sure to visit them at:


 
 
 
 
 
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Have a look at my videos on my YouTube channel.

11 January 2013

Sonar Project Tutorial


Introduction:
This project utilises the HC-SR04 ultrasonic sensor to scan for nearby objects. You can program the Arduino to sound an alarm when the sensor detects an object within a specific vicinity. Connecting it to a computer allows data to be plotted to make a simple sonar scanner. The scanning ability is made possible through the use of a hobby servo motor SG-5010, and an Adafruit motor shield v1.0.
This project could easily be extended to provide object avoidance for any robotics project. This tutorial was designed so that you could see how the components interact, and also to see how you can use and expand the functionality of the motor shield.



Parts Required:
Freetronics Eleven or any compatible Arduino.
Adafruit motor shield v1.0
HC-SR04 Ultrasonic Sensor
MG-995  or SG-5010 Standard servo
Mini Breadboard 4.5cm x 3.5cm
Female header pins to allow easy access to the analog pins on the Motor Shield
Piezo buzzer - to sound alarm
9V Battery and Battery Clip
Wires to connect it all together

Gauge parts:

Paper (to print the face of the gauge), and some glue to stick it to the wood.
MDF Standard panel (3mm width) - for the top and base of the gauge, and the pointer.
Galvanized bracket (25x25x40mm)
Timber screws: Hinge-long threads csk head Phillips drive (4G x 12mm)
Velcro dots - to allow temporary application of the mini-breadboard to the gauge.

The gauge was used as a customisable housing for the Arduino and related parts, and to provide some visual feedback of the servo position.



The Video:




The Arduino Sketch:


 Part of the sketch above was created using Fritzing.

The Servo motor can be connected to either of the Servo motor pins (Digital 9 or 10). In this case, the Servo is attached to digital pin 10.Make sure you read the servo motor data sheet and identify the VCC (5V), GND, and Signal connectors. Not all servos have the same colour wires. My servo motor has a white signal wire, a red VCC wire and a black GND wire.

Also when connecting your wires to the HC-SR04, pay attention to the front of the sensor. It will identify the pins for you. Make sure you have the sensor facing the correct way. In this sketch, the sensor is actually facing towards you.

In this sketch - we connect the
    Echo pin to Analog pin 0 (A0).
    Trigger pin to Analog pin 1 (A1)
    VCC to a 5V line/pin 
    and GND to a GND line/pin

Pay attention to your motor shield, I have seen some pictures on the internet where the 5V and GND are reversed.





Arduino Code:
You can download the Arduino IDE from this site.

The motor shield requires the Adafruit motor shield driver library to be installed into the Arduino IDE.

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/* ArduinoBasics: Sonar Project - Created by Scott C on 10 Jan 2013
 http://arduinobasics.blogspot.com/2013/01/arduino-basics-sonar-project-tutorial.html
 
 This project uses the Adafruit Motor shield library (copyright Adafruit Industries LLC, 2009
 this code is public domain, enjoy!)
 
 The HC-SR04 sensor uses some code from the following sources:
 From Virtualmix: http://goo.gl/kJ8Gl
 Modified by Winkle ink here: http://winkleink.blogspot.com.au/2012/05/arduino-hc-sr04-ultrasonic-distance.html
 And modified further by ScottC here: http://arduinobasics.blogspot.com/
 on 10 Nov 2012.
*/

#include <AFMotor.h>
#include <Servo.h> 

// DC hobby servo
Servo servo1;

/* The servo minimum and maximum angle rotation */
static const int minAngle = 0;
static const int maxAngle = 176;
int servoAngle;
int servoPos;
int servoPin = 10;


/* Define pins for HC-SR04 ultrasonic sensor */
#define echoPin A0 // Echo Pin = Analog Pin 0
#define trigPin A1 // Trigger Pin = Analog Pin 1
#define LEDPin 13 // Onboard LED
long duration; // Duration used to calculate distance
long HR_dist=0; // Calculated Distance
int HR_angle=0; // The angle in which the servo/sensor is pointing
int HR_dir=1; // Used to change the direction of the servo/sensor
int minimumRange=5; //Minimum Sonar range
int maximumRange=200; //Maximum Sonar Range

/*--------------------SETUP()------------------------*/
void setup() {
 //Begin Serial communication using a 9600 baud rate
 Serial.begin (9600);
 
 // Tell the arduino that the servo is attached to Digital pin 10.
 servo1.attach(servoPin);
 
 //Setup the trigger and Echo pins of the HC-SR04 sensor
 pinMode(trigPin, OUTPUT);
 pinMode(echoPin, INPUT);
 pinMode(LEDPin, OUTPUT); // Use LED indicator (if required)
}

/*----------------------LOOP()--------------------------*/
void loop() {
 
 /* check if data has been sent from the computer: */
 if (Serial.available()) {
 
 /* This expects an integer from the Serial buffer */
 HR_angle = Serial.parseInt();
 
 /* If the angle provided is 0 or greater, then move servo to that 
 position/angle and then get a reading from the ultrasonic sensor */
 if(HR_angle>-1){
 /*Make sure that the angle provided does not go beyond the capabilities
 of the Servo. This can also be used to calibrate the servo angle */
 servoPos = constrain(map(HR_angle, 0,180,minAngle,maxAngle),minAngle,maxAngle);
 servo1.write(servoPos);
 
 /* Call the getDistance function to take a reading from the Ultrasonic sensor */
 getDistance();
 }
 }
}

/*--------------------getDistance() FUNCTION ---------------*/
void getDistance(){ 
 
 /* The following trigPin/echoPin cycle is used to determine the
 distance of the nearest object by bouncing soundwaves off of it. */ 
 digitalWrite(trigPin, LOW); 
 delayMicroseconds(2); 

 digitalWrite(trigPin, HIGH);
 delayMicroseconds(10); 
 
 digitalWrite(trigPin, LOW);
 duration = pulseIn(echoPin, HIGH);
 
 //Calculate the distance (in cm) based on the speed of sound.
 HR_dist = duration/58.2;
 
 /*Send the reading from the ultrasonic sensor to the computer */
 if (HR_dist >= maximumRange || HR_dist <= minimumRange){
 /* Send a 0 to computer and Turn LED ON to indicate "out of range" */
 Serial.println("0");
 digitalWrite(LEDPin, HIGH); 
 } else {
 /* Send the distance to the computer using Serial protocol, and
 turn LED OFF to indicate successful reading. */
 Serial.println(HR_dist);
 digitalWrite(LEDPin, LOW);
 }
}

The code above was formatted using hilite.me

Notes:
Servo Angles: You will notice on line 22, the maximum servo angle used was 176. This value was obtained through trial and error (see below).

Calibrating the servo angles
You may need to calibrate your servo in order to move through an angle of 0 to 180 degrees without straining the motor. Go to line 21-22 and change the minAngle to 0 and the maxAngle to 180. Once you load the sketch to the Arduino/Freetronics ELEVEN, you can then open the Serial Monitor and type a value like 10 <enter>, and then keep reducing it until you get to 0. If you hear the servo motor straining, then move it back up to a safe value and change the minimum servo angle to that value. Do the same for the maximum value.

In this example, the servo's minAngle value was 0, and maxAngle value was 176 after calibration, however, as you can see from the video, the physical range of the servo turned out to be 0 to 180 degrees.




The Processing Sketch

You can download the Processing IDE from this site.

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/* Created by ScottC on 10 Jan 2013 
 http://arduinobasics.blogspot.com/2013/01/arduino-basics-sonar-project-tutorial.html
*/

import processing.serial.*;

int distance;
int angle=0;
int direction=1;

int[] alphaVal = new int[100]; // used to fade the lines
int[] distance2 = new int[100]; // used to store the line lengths
int lineSize = 4; // line length multiplier (makes it longer)

String comPortString;
Serial comPort;

/*---------------------SETUP---------------------------*/
void setup( ) {
 size(displayWidth,displayHeight); //allows fullscreen view
 smooth();
 background(0); // set the background to black
 
 /*Open the serial port for communication with the Arduino
 Make sure the COM port is correct - I am using COM port 8 */
 comPort = new Serial(this, "COM8", 9600);
 comPort.bufferUntil('\n'); // Trigger a SerialEvent on new line 
 
 /*Initialise the line alphaValues to 0 (ie not visible) */
 for(int i=0; i<91; i++){
 alphaVal[i] = 0;
 }
}
 
/*---------------------DRAW-----------------*/
void draw( ) {
 background(0); //clear the screen
 
 /*Draw each line and dot */
 for(int i=0; i<91; i++){
 
 /*Gradually fade each line */
 alphaVal[i]=alphaVal[i]-4;
 
 /*Once it gets to 0, keep it there */
 if(alphaVal[i]<0){
 alphaVal[i]=0;
 }
 
 /*The colour of the line will change depending on the distance */
 stroke(255,distance2[i],0,alphaVal[i]);
 
 /* Use a line thickness of 2 (strokeweight) to draw the line that fans
 out from the bottom center of the screen. */
 strokeWeight(2);
 line(width/2, height, (width/2)-cos(radians(i*2))*(distance2[i]*lineSize), height-sin(radians(i*2))*(distance2[i]*lineSize));
 
 /* Draw the white dot at the end of the line which does not fade */
 stroke(255);
 strokeWeight(1);
 ellipse((width/2)-cos(radians(i*2))*(distance2[i]*lineSize), height-sin(radians(i*2))*(distance2[i]*lineSize),5,5);
 }
}

/* A mouse press starts the scan. There is no stop button */
void mousePressed(){
 sendAngle();
}

/*When the computer receives a value from the Arduino, it will update the line positions */
void serialEvent(Serial cPort){
 comPortString = cPort.readStringUntil('\n');
 if(comPortString != null) {
 comPortString=trim(comPortString);
 
 /* Use the distance received by the Arduino to modify the lines */
 distance = int(map(Integer.parseInt(comPortString),1,200,1,height));
 drawSonar(angle,distance);

 /* Send the next angle to be measured by the Arduino */ 
 sendAngle();
 }
}

/*---------------------------sendAngle() FUNCTION----------------*/
void sendAngle(){
 //Send the angle to the Arduino. The fullstop at the end is necessary.
 comPort.write(angle+".");
 
 /*Increment the angle for the next time round. Making sure that the angle sent
 does not exceed the servo limits. The "direction" variable allows the servo
 to have a sweeping action.*/
 angle=angle+(2*direction);
 if(angle>178||angle<1){
 direction=direction*-1;
 }
}

/*-----------------sketchFullScreen(): Allows for FullScreen view------*/
boolean sketchFullScreen() {
 return true;
}

/*----------------- drawSonar(): update the line/dot positions---------*/
void drawSonar(int sonAngle, int newDist){
 alphaVal[sonAngle/2] = 180;
 distance2[sonAngle/2] = newDist;
}

 


The Processing Output


 

11 November 2012

HC-SR04 Ultrasonic Sensor


Introduction:

The HC-SR04 Ultrasonic Sensor is a very affordable proximity/distance sensor that has been used mainly for object avoidance in various robotics projects . It essentially gives your Arduino eyes / spacial awareness and can prevent your robot from crashing or falling off a table. It has also been used in turret applications, water level sensing, and even as a parking sensor. This simple project will use the HC-SR04 sensor with an Arduino and a Processing sketch to provide a neat little interactive display on your computer screen.



Parts Required:
Freetronics Eleven or any compatible Arduino.
HC-SR04 Ultrasonic Sensor
Mini Breadboard 4.5cm x 3.5cm
Protoshield and female header pins (not essential - but makes it more tidy)
Wires to connect it all together




The Video:




The Arduino Sketch:



     The above sketch was created using Fritzing.





Arduino Code:
You can download the Arduino IDE from this site.

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/*
 HC-SR04 Ping distance sensor:
 VCC to arduino 5v 
 GND to arduino GND
 Echo to Arduino pin 7 
 Trig to Arduino pin 8
 
 This sketch originates from Virtualmix: http://goo.gl/kJ8Gl
 Has been modified by Winkle ink here: http://winkleink.blogspot.com.au/2012/05/arduino-hc-sr04-ultrasonic-distance.html
 And modified further by ScottC here: http://arduinobasics.blogspot.com.au/2012/11/arduinobasics-hc-sr04-ultrasonic-sensor.html
 on 10 Nov 2012.
 */


#define echoPin 7 // Echo Pin
#define trigPin 8 // Trigger Pin
#define LEDPin 13 // Onboard LED

int maximumRange = 200; // Maximum range needed
int minimumRange = 0; // Minimum range needed
long duration, distance; // Duration used to calculate distance

void setup() {
 Serial.begin (9600);
 pinMode(trigPin, OUTPUT);
 pinMode(echoPin, INPUT);
 pinMode(LEDPin, OUTPUT); // Use LED indicator (if required)
}

void loop() {
/* The following trigPin/echoPin cycle is used to determine the
 distance of the nearest object by bouncing soundwaves off of it. */ 
 digitalWrite(trigPin, LOW); 
 delayMicroseconds(2); 

 digitalWrite(trigPin, HIGH);
 delayMicroseconds(10); 
 
 digitalWrite(trigPin, LOW);
 duration = pulseIn(echoPin, HIGH);
 
 //Calculate the distance (in cm) based on the speed of sound.
 distance = duration/58.2;
 
 if (distance >= maximumRange || distance <= minimumRange){
 /* Send a negative number to computer and Turn LED ON 
 to indicate "out of range" */
 Serial.println("-1");
 digitalWrite(LEDPin, HIGH); 
 }
 else {
 /* Send the distance to the computer using Serial protocol, and
 turn LED OFF to indicate successful reading. */
 Serial.println(distance);
 digitalWrite(LEDPin, LOW); 
 }
 
 //Delay 50ms before next reading.
 delay(50);
}

The code above was formatted using hilite.me





Processing Code:
You can download the Processing IDE from this site.

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/* The following Processing Sketch was created by ScottC on
 the 10 Nov 2012 : http://arduinobasics.blogspot.com/
 
 Inspired by this Processing sketch by Daniel Shiffman:
 http://processing.org/learning/basics/sinewave.html
 
*/
import processing.serial.*;


int numOfShapes = 60; // Number of squares to display on screen 
int shapeSpeed = 2; // Speed at which the shapes move to new position
 // 2 = Fastest, Larger numbers are slower

//Global Variables 
Square[] mySquares = new Square[numOfShapes];
int shapeSize, distance;
String comPortString;
Serial myPort;

/* -----------------------Setup ---------------------------*/
void setup(){
 size(displayWidth,displayHeight); //Use entire screen size.
 smooth(); // draws all shapes with smooth edges.
 
 /* Calculate the size of the squares and initialise the Squares array */
 shapeSize = (width/numOfShapes); 
 for(int i = 0; i<numOfShapes; i++){
 mySquares[i]=new Square(int(shapeSize*i),height-40);
 }
 
 /*Open the serial port for communication with the Arduino
 Make sure the COM port is correct - I am using COM port 8 */
 myPort = new Serial(this, "COM8", 9600);
 myPort.bufferUntil('\n'); // Trigger a SerialEvent on new line
}

/* ------------------------Draw -----------------------------*/
void draw(){
 background(0); //Make the background BLACK
 delay(50); //Delay used to refresh screen
 drawSquares(); //Draw the pattern of squares
}


/* ---------------------serialEvent ---------------------------*/
void serialEvent(Serial cPort){
 comPortString = cPort.readStringUntil('\n');
 if(comPortString != null) {
 comPortString=trim(comPortString);
 
 /* Use the distance received by the Arduino to modify the y position
 of the first square (others will follow). Should match the
 code settings on the Arduino. In this case 200 is the maximum
 distance expected. The distance is then mapped to a value
 between 1 and the height of your screen */
 distance = int(map(Integer.parseInt(comPortString),1,200,1,height));
 if(distance<0){
 /*If computer receives a negative number (-1), then the
 sensor is reporting an "out of range" error. Convert all
 of these to a distance of 0. */
 distance = 0;
 }
 }
}


/* ---------------------drawSquares ---------------------------*/
void drawSquares(){
 int oldY, newY, targetY, redVal, blueVal;
 
 /* Set the Y position of the 1st square based on 
 sensor value received */
 mySquares[0].setY((height-shapeSize)-distance);
 
 /* Update the position and colour of each of the squares */
 for(int i = numOfShapes-1; i>0; i--){
 /* Use the previous square's position as a target */
 targetY=mySquares[i-1].getY();
 oldY=mySquares[i].getY();
 
 if(abs(oldY-targetY)<2){
 newY=targetY; //This helps to line them up
 }else{
 //calculate the new position of the square
 newY=oldY-((oldY-targetY)/shapeSpeed);
 }
 //Set the new position of the square
 mySquares[i].setY(newY);
 
 /*Calculate the colour of the square based on its
 position on the screen */
 blueVal = int(map(newY,0,height,0,255));
 redVal = 255-blueVal;
 fill(redVal,0,blueVal);
 
 /* Draw the square on the screen */
 rect(mySquares[i].getX(), mySquares[i].getY(),shapeSize,shapeSize);
 }
}

/* ---------------------sketchFullScreen---------------------------*/
// This puts processing into Full Screen Mode
boolean sketchFullScreen() {
 return true;
}

/* ---------------------CLASS: Square ---------------------------*/
class Square{
 int xPosition, yPosition;
 
 Square(int xPos, int yPos){
 xPosition = xPos;
 yPosition = yPos;
 }
 
 int getX(){
 return xPosition;
 }
 
 int getY(){
 return yPosition;
 }
 
 void setY(int yPos){
 yPosition = yPos;
 }
}

The code above was formatted using hilite.me

 
 



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Follow me on Twitter by looking for ScottC @ArduinoBasics.
Have a look at my videos on my YouTube channel.


 
 

 
 
 



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