Interfacing of TMP36 Temperature Sensor with an Arduino in Tinkerad.

 

Interfacing of TMP36 Temperature Sensor with an Arduino in Tinkerad.

This project will turn the Arduino into a thermometer! By using the tmp36 temperature sensor. We can able to measure our body temperature and turn on the 3 LEDs. Green LED indicates the low-temperature range, Yellow LED indicates the medium temperature range and Red LED indicates the high-temperature range. One can test the circuit starting the simulation, clicking on the sensor, then adjusting its temperature value using the slider, and can test the desired resulting LED patterns. For making the actual circuit, you need to use the Arduino, breadboard, USB cable, male-female jumper wires, three LEDs, three resistors (any value from 100-1K, 220 ohms), a TMP36 sensor,

 

Circuit Diagram:

 

Components Required:

§  Arduino UNO

§  TMP36 (Temperature sensor)

§  Resistor-03

§  LED – Green

§  LED – Yellow

§  LED – Red

§  Connecting wires

 

Connection:

The hardware a part of this project is quite simple and easy to place together. First of all, make the connections for the TMP36 sensor with the Arduino. The connections for the TMP36 sensor with the Arduino given in the above circuit diagram:

Connect the VCC pin of the TMP36 sensor to the 5V pin on the Arduino.

Connect GND pin of TMP36 sensor to the GND terminal of An Arduino.

Connect the green LED anode pin to pin no 4 of an Arduino

Connect the yellow LED anode pin to pin no 3 of an Arduino.

Connect the red LED anode pin to pin no 2 of an Arduino.

Connect the cathode of all the LEDs to the Arduino GND.

About TMP 36 Temperature Sensor:

The TMP36 temperature sensor is used to measure temperature using an Arduino in various applications! This sensor can measure a wide range of temperature range from -40°C to 125°C, and its low-cost sensor, making it a popular choice. TMP36 gives a voltage output that is straightaway proportional to the outside temperature. The TMP36 needs a very low voltage power supply to operate, it’s an accurate temperature sensor.

It won’t require any external calibration circuitry to give the accuracies of ±1°C at +25°C and ±2°C over the −40°C to +125°C temperature range. TMP36 creates a varying voltage output depending on the outside temperature it senses. It has three pins: one which is connected to the ground, another one connects to 5 volts, and a third one is the output pin which is connected to an analog input of an Arduino that is A0

 

Pinout:

Working of project:

As per the circuit diagram, the output voltage of the TMP36 is connected to the analog input pin of an Arduino. The analog Pin A0 reads the voltage and gives some analog value to Arduino. Or in simple words we can say the TMP36 sensor produces a changing voltage signal depending on the outside temperature it senses So, when temperature increases, the pin connected to A0 increases its voltage. And You can see in the circuit diagram that three LEDs are each connected to their digital pin.

This circuit operates in three mode

When the temperature is low it will turn on the green LED.

When the temperature medium it will turn on the yellow LED.

When the temperature is high it will turn on the red LED.

Code Explanation (Block Based):

 

First of all, we create a variable named temp, to store the temperature that is nothing but the sensor value to declare the variable click on the variable block and create a variable, see the below picture.

 

After declaring the variable drag out the set block and set to the following blocks

 

Step to set the variable to “map” or converting temperature into degree Celsius

Step 1: In the Math section, take out a "map" block, and merge two arithmetic blocks inside the first field.

Step 2: Set the temperature range -40 to 125.

Step 3: go to the Input section and take out an "analog read pin A0" block, and fix it into the first arithmetic block inside the "map" block.

Step 4: now set the math’s blocks to "(read analog pin A0 - 20) x 3.04".

After completing all steps, it should look like following picture

 

Take out the serial monitor block to print the temperature on the screen

 

[ Note: About an Arduino map function

The map function in Arduino is used to change one scale of values (that is analogue input values) into another scale of values, and a mainly it is use to read an analogue input which is 10 bit that is it converts varying voltage to 0 to 1023 using internal ADC (analogue to digital converter) and map function change the output to desired range of values.for ex.output values from 0 to 255.

Example “C” code:

/* Map an analog value to 8 bits (0 to 255) */

void setup() {}

 

void loop() {

  int val = analogRead(0);

  val = map(val, 0, 1023, 0, 255);

  analogWrite(9, val);

}

For reference click here Arduino map function ]

Let’s use the main conditional statement of the program that is ‘if’ block

 

 

 

 

first if statement block:

In this if block we will use the less than “<” comparison operator.

Condition:

 If the temperature value is less than 25 degree Celsius then pin 4 will be high and pin no 3 and pin no 2 will be Low. This will make green LED to turn on and other two LEDs will turn off this indicates the low temperature.

Second if statement block:

In this, if block we will use the three different operators two comparison operator that is less than “<” comparison operator and “>” greater than comparison operator and last the logical operator that is “&&” (and) operator

Condition:

 If the temperature value is less than 50 degrees Celsius and If the temperature value is greater than 25 degrees Celsius then pin 3 will be high and pin no 4 and pin no 2 will be Low. This will make green-yellow LED turn on and other two LEDs will turn off this indicates the medium temperature.

Third if statement block:

In this, if block we will use the three different operators two comparison operator that is less than “<” comparison operator and “>” greater than comparison operator and last the logical operator that is “&&” (and) operator.

Condition:

 If the temperature value is less than 125 degrees Celsius and If the temperature value is greater than 50 degrees Celsius then pin 2 will be high and pin no 4 and pin no 2 will be Low. This will make the green-yellow RED turn on and the other two LEDs will turn off this indicates the high temperature.

 

 

[ Note:The logical operators return TRUE or FALSE, which are defined as 1 and 0, respectively, logical operators use where needs to make the decision based on multiple conditions.

&& is the logical and operator: it returns a true value only when if both the conditions are true and returns a false value when both the conditions are false]

 Arduino Sketch:

int temp = 0;   void setup() {   pinMode(A0, INPUT);   Serial.begin(9600);     pinMode(4, OUTPUT);   pinMode(3, OUTPUT);   pinMode(2, OUTPUT); }   void loop() {   temp = map(((analogRead(A0) - 20) * 3.04), 0, 1023, -40, 125);   Serial.println(temp);   if (temp < 25) {     digitalWrite(4, HIGH);     digitalWrite(3, LOW);     digitalWrite(2, LOW);   }   if (temp > 25 && temp < 50) {     digitalWrite(4, LOW);     digitalWrite(3, HIGH);     digitalWrite(2, LOW);   }   if (temp > 50 && temp < 125) {     digitalWrite(4, LOW);     digitalWrite(3, LOW);     digitalWrite(2, HIGH);   }   delay(10); // Delay a little bit to improve simulation performance }