Category Archives: Tutorial

In this lesson we explore use of the HC-SR04 sensor to measure the speed of sound. The hookup and programming are pretty simple. The Elegoo Kit includes this sensor, so if you have the kit, you will be using the same hardware we are using. This project builds on the work we did in Lesson 53.

For this build we will be using an Arduino Nano, which allows the project to be built on a single breadboard. This allows cleaner build, and one less likely to have problems from intermittent connections. The build neatness is also facilitated by using small straight jumper wires, which you can get HERE.

You can connect the sensor up according to this schematic:

HC-SR04-Schematic — Schematic for Connecting the HC-SR04 to an Arduino

The connection pins are the same when connecting to a Nano.

The video below explains how to measure speed of sound from data coming from this sensor.

Code used in Today’s Lesson:

int trigPin=12;
int echoPin=11;
int pingTravelTime;
void setup() {
  // put your setup code here, to run once:
pinMode(trigPin,OUTPUT);
pinMode(echoPin,INPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(trigPin,LOW);
delayMicroseconds(10);
digitalWrite(trigPin,HIGH);
delayMicroseconds(10);
digitalWrite(trigPin,LOW);
pingTravelTime=pulseIn(echoPin,HIGH);
delay(25);
Serial.println(pingTravelTime);
}

int trigPin=12;

int echoPin=11;

int pingTravelTime;

void setup() {

// put your setup code here, to run once:

pinMode(trigPin,OUTPUT);

pinMode(echoPin,INPUT);

Serial.begin(9600);

}

void loop() {

// put your main code here, to run repeatedly:

digitalWrite(trigPin,LOW);

delayMicroseconds(10);

digitalWrite(trigPin,HIGH);

delayMicroseconds(10);

digitalWrite(trigPin,LOW);

pingTravelTime=pulseIn(echoPin,HIGH);

delay(25);

Serial.println(pingTravelTime);

}

Arduino, Tutorial

Arduino Tutorial 53: Understanding and Connecting the HC-SR04 Sensor

March 17, 2020 admin

In this lesson we explore using the HC-SR04 sensor. The sensor sends out a ping, and then waits to hear the echo. It measures the time between when the ping is sent and when the echo is heard. Knowing pingTravelTime, allows you to calculate distance from the sensor. In this lesson we will show you how to connect the sensor, and program it to read pingTravelTime. In future lessons we will show you how to change this into distance.

Notice we used an Arduino Nano, which allows the entire project to be build on a single breadboard. This allows a neater, smaller build, and one less likely to have problems from poor or loose connections. The build neatness is also facilitated by using small straight jumper wires, which you can get HERE.

Connecting up the HC-SR04 sensor is simple, as illustrated in this diagram:

This video will take you through our build and initial work step-by-step.

The simple code below is what we used in the video to begin making measurements with the sensor.

int trigPin=12;
int echoPin=11;
int pingTravelTime;
void setup() {
  // put your setup code here, to run once:
pinMode(trigPin,OUTPUT);
pinMode(echoPin,INPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(trigPin,LOW);
delayMicroseconds(10);
digitalWrite(trigPin,HIGH);
delayMicroseconds(10);
digitalWrite(trigPin,LOW);
pingTravelTime=pulseIn(echoPin,HIGH);
delay(25);
Serial.println(pingTravelTime);
}

int trigPin=12;

int echoPin=11;

int pingTravelTime;

void setup() {

// put your setup code here, to run once:

pinMode(trigPin,OUTPUT);

pinMode(echoPin,INPUT);

Serial.begin(9600);

}

void loop() {

// put your main code here, to run repeatedly:

digitalWrite(trigPin,LOW);

delayMicroseconds(10);

digitalWrite(trigPin,HIGH);

delayMicroseconds(10);

digitalWrite(trigPin,LOW);

pingTravelTime=pulseIn(echoPin,HIGH);

delay(25);

Serial.println(pingTravelTime);

}

Arduino, Tutorial

Arduino Tutorial 52: Portable Temperature and Humidity Sensor with DHT11

March 10, 2020 admin

portable temperature sensor — This shows our completed build creating a completely portable DHT11 sensor system

In this lesson we build a completely portable Temperature and Humidity Sensor using the DHT11 sensor. The project is powered by a 9 Volt battery, through the power supply board supplied in the Elegoo Kit. This project builds on the work we did in Lessons 50 and 51.

Also, notice we used an Arduino Nano, which allows the entire project to be build on a single breadboard. This allows a neater, smaller build, and one less likely to have problems from poor or loose connections. The build neatness is also facilitated by using small straight jumper wires, which you can get HERE.

In the configuration in this project, the regulated power supply is providing power to the Arduino through the 5 Volt pin. In such cases, you should not Also plug the USB cable into the arduino. When powering the Arduino with a regulated power supply, do not connect the USB. If you need to program the arduino, disconnect the external power supply first.

The video below gives a detailed step-by-step description of the project.

The code we developed is presented below:

#include "DHT.h"
#define Type DHT11
#include <LiquidCrystal.h>
int rs=7;
int en=8;
int d4=9;
int d5=10;
int d6=11;
int d7=12;
LiquidCrystal lcd(rs,en,d4,d5,d6,d7);

int sensePin=2;
DHT HT(sensePin,Type);
float humidity;
float tempC;
float tempF;
int setTime=500;
int dt=1000;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
HT.begin();
delay(setTime);
lcd.begin(16,2);

}

void loop() {
humidity=HT.readHumidity();
tempC=HT.readTemperature();
tempF=HT.readTemperature(true);

lcd.setCursor(0,0);
lcd.print("Temp F= ");
lcd.print(tempF);
lcd.setCursor(0,1);
lcd.print("Humidity= ");
lcd.print(humidity);
lcd.print(" %");
delay(500);
lcd.clear();

Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print("% Temperature ");
Serial.print(tempC);
Serial.print(" C ");
Serial.print(tempF);
Serial.println(" F ");

}

#include "DHT.h"

#define Type DHT11

#include <LiquidCrystal.h>

int rs=7;

int en=8;

int d4=9;

int d5=10;

int d6=11;

int d7=12;

LiquidCrystal lcd(rs,en,d4,d5,d6,d7);

int sensePin=2;

DHT HT(sensePin,Type);

float humidity;

float tempC;

float tempF;

int setTime=500;

int dt=1000;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

HT.begin();

delay(setTime);

lcd.begin(16,2);

}

void loop() {

humidity=HT.readHumidity();

tempC=HT.readTemperature();

tempF=HT.readTemperature(true);

lcd.setCursor(0,0);

lcd.print("Temp F= ");

lcd.print(tempF);

lcd.setCursor(0,1);

lcd.print("Humidity= ");

lcd.print(humidity);

lcd.print(" %");

delay(500);

lcd.clear();

Serial.print("Humidity: ");

Serial.print(humidity);

Serial.print("% Temperature ");

Serial.print(tempC);

Serial.print(" C ");

Serial.print(tempF);

Serial.println(" F ");

}

Arduino, Tutorial

Arduino Tutorial 51: DHT11 Temperature and Humidity Sensor with LCD Display

March 3, 2020 admin

In this lesson we work towards a stand alone Temperature and Humidity project using the DHT11 sensor.

This video will take you through the build and coding step-by-step, and the schematics below will help you follow along at home.

Our goal in this lesson is to add an LCD to the project. In lesson 50, we got the sensor working, and here we want to get the LCD connected. An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT. In addition, your build can be much neater, cleaner and more stable is you use an arduino nano, instead of the standard arduino uno. The nano is small, and has male pins that allow it to be plugged directly into the breadboard, as seen above. I strongly suggest picking up an Arduino Nano, which you can get HERE. This lesson follows on to the work done in lesson 50. To recap, the DHT11 is connected as follows:

DHT11 Sensor — Connection schematic for the DHT11 Temperature Sensor.

You will also need to add the LCD, using the following schematic:

Arduino LCD Schematic — This schematic will allow you to connect the LCD to the

In my photograph at the top of the post, you can see it is important to keep the build neat, as there are lots of connections which must be made. Neat work is facilitated is you use short jumper wires, instead of the big male to male wires. You can get a jumper wire set that will keep your work neat HERE. I am not trying to sell you a bunch of junk, but as projects get more complicated, you really need to use the short straight wires, or your build will become a rat’s nest.

We develop the code in the video in detail, but you can get the finished code down below.

#include "DHT.h"
#define Type DHT11
#include <LiquidCrystal.h>
int rs=7;
int en=8;
int d4=9;
int d5=10;
int d6=11;
int d7=12;
LiquidCrystal lcd(rs,en,d4,d5,d6,d7);

int sensePin=2;
DHT HT(sensePin,Type);
float humidity;
float tempC;
float tempF;
int setTime=500;
int dt=1000;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
HT.begin();
delay(setTime);
lcd.begin(16,2);

}

void loop() {
humidity=HT.readHumidity();
tempC=HT.readTemperature();
tempF=HT.readTemperature(true);

lcd.setCursor(0,0);
lcd.print("Temp F= ");
lcd.print(tempF);
lcd.setCursor(0,1);
lcd.print("Humidity= ");
lcd.print(humidity);
lcd.print(" %");
delay(500);
lcd.clear();

Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print("% Temperature ");
Serial.print(tempC);
Serial.print(" C ");
Serial.print(tempF);
Serial.println(" F ");

}

#include "DHT.h"

#define Type DHT11

#include <LiquidCrystal.h>

int rs=7;

int en=8;

int d4=9;

int d5=10;

int d6=11;

int d7=12;

LiquidCrystal lcd(rs,en,d4,d5,d6,d7);

int sensePin=2;

DHT HT(sensePin,Type);

float humidity;

float tempC;

float tempF;

int setTime=500;

int dt=1000;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

HT.begin();

delay(setTime);

lcd.begin(16,2);

}

void loop() {

humidity=HT.readHumidity();

tempC=HT.readTemperature();

tempF=HT.readTemperature(true);

lcd.setCursor(0,0);

lcd.print("Temp F= ");

lcd.print(tempF);

lcd.setCursor(0,1);

lcd.print("Humidity= ");

lcd.print(humidity);

lcd.print(" %");

delay(500);

lcd.clear();

Serial.print("Humidity: ");

Serial.print(humidity);

Serial.print("% Temperature ");

Serial.print(tempC);

Serial.print(" C ");

Serial.print(tempF);

Serial.println(" F ");

}

Arduino, Tutorial

Arduino Tutorial 50: How to Connect and Use the DHT11 Temperature and Humidity Sensor

February 25, 2020 admin

In this lesson we show how to measure Temperature and Humidityusing the DHT11 sensor. This is a relatively simple sensor to use, but you will have to download and install a library. In our earlier lessons, we have used libraries before, but this is the first time you will have to download a library. The library I used was downloaded from HERE. The video explains in detail how to install the library, but in a nutshell you download the library from clicking the link on that page. Then you need to open the downloaded zip file, and then drag and drop the contents of the zip file to your desktop. Next you must determine where your arduino library folder is. You can do that by going to the arduino IDE, and under “file” select preferences. This will show you your “Sketchbook Location”, and that folder will contain your libraries folder. The folder you dragged and dropped onto your desktop should be dragged and dropped now into this library folder. The video shows you how to do this if this description is not clear. Now you will need to connect the sensor, according to this schematic:

The video develops the code to use this sensor step-by-step, but the code is included below for your convenience.

#include "DHT.h"
#define Type DHT11
int sensePin=2;
DHT HT(sensePin,Type);
float humidity;
float tempC;
float tempF;
int setTime=500;
int dt=1000;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
HT.begin();
delay(setTime);
}

void loop() {
humidity=HT.readHumidity();
tempC=HT.readTemperature();
tempF=HT.readTemperature(true);

Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print("% Temperature ");
Serial.print(tempC);
Serial.print(" C ");
Serial.print(tempF);
Serial.println(" F ");
delay(dt);


}

#include "DHT.h"

#define Type DHT11

int sensePin=2;

DHT HT(sensePin,Type);

float humidity;

float tempC;

float tempF;

int setTime=500;

int dt=1000;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

HT.begin();

delay(setTime);

}

void loop() {

humidity=HT.readHumidity();

tempC=HT.readTemperature();

tempF=HT.readTemperature(true);

Serial.print("Humidity: ");

Serial.print(humidity);

Serial.print("% Temperature ");

Serial.print(tempC);

Serial.print(" C ");

Serial.print(tempF);

Serial.println(" F ");

delay(dt);

}

An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

Technology Tutorials

Category Archives: Tutorial

Arduino Tutorial 54: Measuring Speed of Sound With HC-SR04 Sensor

Arduino Tutorial 53: Understanding and Connecting the HC-SR04 Sensor

Arduino Tutorial 52: Portable Temperature and Humidity Sensor with DHT11

Arduino Tutorial 51: DHT11 Temperature and Humidity Sensor with LCD Display

Arduino Tutorial 50: How to Connect and Use the DHT11 Temperature and Humidity Sensor

Making The World a Better Place One High Tech Project at a Time. Enjoy!