App Inventor Arduino DHT11 Project

Display the temperature measured by DHT11 sensor in smartphone

07-05-21 3601

Purpose of this tutorial:

In this tutorial we will see how to send the temperature value of the DTH11 sensor to the smarthpone via bluetooth.

This is why we are going to create two programs: a mobile application with App Inventor for the smartphone and a program for the Arduino board.

Necessary components

Arduino
Smartphone
DHT11 temperature sensor
wire connections

Mounting

Program

Here is the program that allows you to connect the Arduino board to the smartphone and send a message containing the temperature value measured by the DHT11 sensor via bluetooth.

#include <SoftwareSerial.h>
#include <dht11.h>
#define DHT11PIN 4 // broche DATA -> broche 4
dht11 DHT11;
SoftwareSerial hc06(2,3);

void setup(){
hc06.begin(9600);
}

void loop(){
DHT11.read(DHT11PIN);
delay(1000);
hc06.print((float)DHT11.temperature); //sends the temperature value to the smartphone
}

#include <SoftwareSerial.h>

#include <dht11.h>

#define DHT11PIN 4 // broche DATA -> broche 4

dht11 DHT11;

SoftwareSerial hc06(2,3);

void setup(){

hc06.begin(9600);

}

void loop(){

DHT11.read(DHT11PIN);

delay(1000);

hc06.print((float)DHT11.temperature); //sends the temperature value to the smartphone

}

Creation of the application with App Inventor:

We will create a mobile application named ‘temperature_arduino’ with App Inventor which allows you to receive a message from the Arduino board.

We propose to create the design of the application, with the following visual:

Programming with App Inventor

To program the application, App Inventor offers us to use the Blocks space, which allows you to create a program in the form of a block diagram. Very easy to use but requiring a little programming logic.

Here is the program of the application created in the Blocks area of the Inventor App: