DIY Room Temperature Detector

Now you can build your own room temperature monitor using an Arduino board. The circuit is a combination of an Arduino UNO board, LM35 temperature sensor, and 7 segment display. It will display the temperature on the 7 segment in degree C. It can be powered from any standard Arduino AC mains adaptor (9VDC), or from a suitable battery. First of all note that this circuit can not measure the temperature of the whole city or province.It can only measure the temperature of the surroundings!

Step 1: Things You Will Need

you will need arduino starter kit

you can buy kit from here

Discount coupon code：GBDADD

following things will required from the kit:

arduino uno.

7 segment .

LM35(temperature) sensor.

A buzzer

RGB LED module.

connecting wires.

A battery.

A registor.

A bread board

A laptop or pc having arduino IDE installed.

etc.

Step 2:

Now make the circuit according to given picture above.

connect 2nd pin to 9th pin to seven segment display.

arduino pin 7segment pin

2nd => e

3rd => d

4th => c

5th => dp

6th => b

7th => a

8th => f

9th => g

now coonect A0 pin arduino to 2nd pin of LM35.

now connect RGB led and buzzer to arduino uno pin no.0,1,13 and 12.

Step 3: Programming.....

Just copy and paste following code into Arduino IDE and burn the code into Arduino UNO///

inti=0;

intval;

int temp=0;

void setup()

{

Serial.begin(9600);

pinMode(2,OUTPUT);

pinMode(3,OUTPUT);

pinMode(4,OUTPUT);

pinMode(5,OUTPUT);

pinMode(6,OUTPUT);

pinMode(7,OUTPUT);

pinMode(8,OUTPUT);

pinMode(9,OUTPUT);

pinMode(10,OUTPUT);

pinMode(11,OUTPUT);

pinMode(13,OUTPUT);

pinMode(12,OUTPUT);

pinMode(1,OUTPUT);

pinMode(0,OUTPUT);

digitalWrite(0,LOW);

digitalWrite(12,LOW);

digitalWrite(1,LOW);

digitalWrite(13,LOW);

digitalWrite(10,LOW);

digitalWrite(11,LOW);

}

void loop()

{

val = analogRead(A0);

float mv = ( val/1024.0)*5000;

intcel = mv/10;

if(cel<=30)

{

digitalWrite(0,HIGH);

digitalWrite(1,LOW);

digitalWrite(12,LOW);

delay(10);

digitalWrite(0,LOW);

digitalWrite(1,LOW);

digitalWrite(12,LOW);

digitalWrite(13,LOW);

//Serial.println("lower 30");

}

if(cel>30 &&cel<40)

{

digitalWrite(0,LOW);

digitalWrite(1,HIGH);

digitalWrite(12,LOW);

delay(10);

digitalWrite(0,LOW);

digitalWrite(1,LOW);

digitalWrite(12,LOW);

digitalWrite(13,LOW);

//Serial.println("Higher 30");

}

if(cel>=40)

{

digitalWrite(13,HIGH);

digitalWrite(0,LOW);

digitalWrite(1,LOW);

digitalWrite(12,HIGH);

delay(10);

digitalWrite(0,LOW);

digitalWrite(1,LOW);

digitalWrite(12,LOW);

digitalWrite(13,LOW);

//Serial.println("Higher 40");

}

else{

digitalWrite(0,LOW);

digitalWrite(1,LOW);

digitalWrite(12,LOW);

}

temp=cel/10;

digitalWrite(11,HIGH);

SevenSegament(temp);

digitalWrite(11,LOW);

i=cel%10;

digitalWrite(10,HIGH);

SevenSegament(i);

digitalWrite(10,LOW);

}

voidSevenSegament(int j)

{

if(j==0){

digitalWrite(2,LOW);

digitalWrite(3,LOW);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,LOW);

digitalWrite(8,LOW);

digitalWrite(9,HIGH);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

}

if(j==1){

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

}

if(j==2){

digitalWrite(2,LOW);

digitalWrite(3,LOW);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,LOW);

digitalWrite(8,HIGH);

digitalWrite(9,LOW);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

}

if(j==3)

{digitalWrite(2,HIGH);

digitalWrite(3,LOW);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,LOW);

digitalWrite(8,HIGH);

digitalWrite(9,LOW);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

}

if(j==4){

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,HIGH);

digitalWrite(8,LOW);

digitalWrite(9,LOW);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);}

if(j==5){

digitalWrite(2,HIGH);

digitalWrite(3,LOW);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,LOW);

digitalWrite(8,LOW);

digitalWrite(9,LOW);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);}

if(j==6){

digitalWrite(2,LOW);

digitalWrite(3,LOW);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,LOW);

digitalWrite(8,LOW);

digitalWrite(9,LOW);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

}

if(j==7){

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,LOW);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);}

if(j==8)

{

digitalWrite(2,LOW);

digitalWrite(3,LOW);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,LOW);

digitalWrite(8,LOW);

digitalWrite(9,LOW);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);}

if(j==9){

digitalWrite(2,HIGH);

digitalWrite(3,LOW);

digitalWrite(4,LOW);

digitalWrite(5,HIGH);

digitalWrite(6,LOW);

digitalWrite(7,LOW);

digitalWrite(8,LOW);

digitalWrite(9,LOW);

digitalWrite(2,HIGH);

digitalWrite(3,HIGH);

digitalWrite(4,HIGH);

digitalWrite(5,HIGH);

digitalWrite(6,HIGH);

digitalWrite(7,HIGH);

digitalWrite(8,HIGH);

digitalWrite(9,HIGH);

}

}

Step 4: Power...

Now just give power from electric cell pack which is provided in kit.you will see temperature reading on seven-segment.

That's it.Enjoy.