▷ How to make a digital thermometer using Arduino?

A digital thermometer measures the temperature of the human body and displays it on the screen. The digital thermometers that are available on the market are a bit expensive. Therefore, if we have the necessary components at home, we can make a low cost digital thermometer at home with the same efficiency of a commercially available thermometer.

Digital thermometer

How do you use a temperature sensor to measure body temperature?

We know that we are going to measure the body temperature of a person using Arduino. Then, let's start compiling more information to start the project.

Paso 1: components

If you want to avoid any inconvenience in the middle of any project, it is best to make a complete list of all the components that we are going to use. The second step, before starting the circuit, is to make a brief study of all these components. Below is a list of all the components we need in this project.

Paso 2: study the components

As we already made a list of the components, we are going to advance and make a brief study of the operation of each component.

Arduino Nano is a microcontroller board. The microcontroller it contains is ATmega328P. You need a C code to work. In this code, we tell the controller how and what operations to perform.

Arduino Nano

The LM35 is a temperature sensor. Its shape is like a transistor. Produces an output voltage that is directly proportional to temperature. The output voltage can easily be used to find the temperature in degrees Celsius. Better than thermistors because it is more sensitive to temperature and provides accurate readings. His range is -55 degrees a 150 Celsius degrees.

Paso 3: do the circuit

Now let's assemble all the components to make a circuit.

1. Insert the Arduino Nano board into the breadboard.

2. Take the LM35 sensor and connect its pins through the male and female jumper wires to the Arduino. Connect the Vcc and ground pin to the 5V and ground of the Arduino Nano board and connect the output pin to Arduino A5. It is better to connect a ww0-ohm resistor with the Vcc pin of the LM35 temperature sensor.LM35 (Photo courtesy: Instruction)

Paso 4: start with Arduino

If you are not yet familiar with the Arduino IDE. Do not worry, here is a step by step procedure to configure and use the Arduino IDE:

1. Download the latest version of the Arduino IDE from Arduino.

2. Connect your Arduino nano board to your laptop and open the control panel.

3. Click Hardware and Sound and then Devices and Printers. Here you will find the port your Arduino Nano board is connected to. On my laptop, it is COM14 but it may be different on your laptop.Find the port

4. Click on the tools menu and set the board to Arduino Nano.Configuration table

5. In the same tools menu, set processor as ATmega328P (Old Bootloader).Adjust the processor

6. Now, in the same tools menu, set the port you have already observed on devices and printers.Configuration port

7. Download the attached code and copy it to your IDE. Click the upload button to save the code to your Arduino Nano board.Increase

Click here to download the code.

Paso 5: Code.

The code is very simple. Briefly explained below:

1. The Arduino pin to take the analog input is initialized at first. All variables that will be used later to save different values ​​are also initialized here.

const int sensor=A5; // Assigning Analog Pin A5 to Variable "sensor
Temp. flotation; //variable to save the temperature in degrees centigrade
Temp. flotation; //variable to save the temperature in degrees Ferhanite
float vout; // temporary variable to hold the sensor reading

2. void setup () is a function in which we initialize the Arduino pins to use them as INPUT or OUTPUT. The baud rate is also configured in this function. The baud rate is the communication speed of the microcontroller board with the connected sensors.

avoid setup() {
PinMode(sensor,INPUT); // Setting the sensor pin as input
Serie... starts (9600);
}

3. void loop () is a function that runs repeatedly in a loop. In this function, the input from the Arduino board is processed and the output is sent to the other pins or displayed on the serial monitor.

void loop() {
vout=analogRead(sensor); //Reading sensor value
vout = vout *(5.0/1023.0);
tempc=vout; // Storage value in degrees centigrade
tempf =(vout*1.8)+32; // Convert the temperature to ferranite
Serial.println("in degree C = ");
Serial.print(tempc);
Serial.println("in degree F = ");
Serial.print(tempf);
Serial.println(" ");
delay(500); //Delay of 1 second for ease of view
}

In the above function, an analog input goes to pin A5 of the Arduino. This analog input is converted to digital format through a formula. In this formula, the analog input is multiplied by the total volts provided by the microcontroller board and divided by the maximum analog value which is 1023.

When this analog data is converted to digital format, are interpreted directly as the temperature in degrees Celsius. To display the feranite temperature additionally on the serial monitor, we have used a formula to convert this temperature into feranite and then show it on the screen.

Now, how we have made a digital thermometer using Arduino. Put this LM35 sensor on your arm and cover it with a cloth and enjoy measuring your body temperature.