Arduino IoT Cloud Lesson 4: HC-SR04

Step 1: Requirements

1X Arduino Nano 33 IoT

1X breadboard

4X jumper wires

1X HC-SR04

1X Breadboard nutrition. (5V)

Arduino Build

Step 2: Setup Arduino Create

For the project we create a new “Thing”. You can also use one of the “Thing” s from the previous lessons. But to keep everything clear, we are creating a new “Thing” for this project. In this project we have called the ”Thing” Arduino-IoT-Lesson-4-Distance-Sensor. When the thing is created we add a property. The property in this case is a Distance sensor. For type we again go for ”Length (centimeters)”. We only want to read data, so the permission must be set to read only. At the bottom of the page you will see History. We select this to store the incoming data. This allows us to later see a graph with the measured values.

Now that we have made the property we are going to build and wire it.

In the image below you can already see some data. You will only see this once the code has been uploaded. The current distance is shown in the left image. At the top right you see a small graph. If you click on this you will see the right image. The collected data is converted into a graph. You can see the last minute, 30 minutes, hour, etc. 

Step 2: Building and Wiring

Step 3: Programming

 We program the Arduino in the same way as in the previous lessons. The code you will use for this is below. If you want to learn it better, type the code instead of copying and pasting it. You will learn to program better.

Once you have written the code you can upload it to the Arduino. If this is successful, go back to the IoT Cloud, click on dashboard† You should now see data as shown in the images in step 1.

#define ULTRASONIC_TRIG_PIN 11 // pin TRIG is D11
#define ULTRASONIC_ECHO_PIN 12 //pin ECHO is D12
#include "thingProperties.h"

void setup () {
Serial.begin (9600);
delay (1500);

initProperties ();

ArduinoCloud.begin (ArduinoIoTPreferredConnection);

setDebugMessageLevel (2);
ArduinoCloud.printDebugInfo ();

pinMode (ULTRASONIC_TRIG_PIN, OUTPUT); // The trigger is defined as output
pinMode (ULTRASONIC_ECHO_PIN, INPUT); // The Echo is defined as input
}

void loop () {
ArduinoCloud.update ();

long duration, Distance_Sensor;
digitalWrite (ULTRASONIC_TRIG_PIN, LOW);
delayMicroseconds (2);

digitalWrite (ULTRASONIC_TRIG_PIN, HIGH); // With this we send an ultrasonic sound
delayMicroseconds (10); // We will send for 10 milliseconds

digitalWrite (ULTRASONIC_TRIG_PIN, LOW); // Now we stop transmitting
duration = pulseIn (ULTRASONIC_ECHO_PIN, HIGH); // Here we measure how long it takes before we get the ultrasound back.
distance_Sensor = (duration / 2) / 29.1; // With this we ensure that the values ​​in cm are displayed in the IoT cloud
Serial.print (”Distance:“); // To be able to check whether everything is working without an IoT Cloud connection, we also display it in the Monitor
Serial.print (distance_Sensor);
Serial.println ("cm");
}