Temperature Sensor With Arduino UNO

Intro: Temperature Sensor With Arduino UNO

Learn how to read Temperature using LM35 Temperature sensor!

The LM35 series are precision integrated-circuit temperature devices with an output voltage linearly proportional to the Centigrade temperature. The LM35 device has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from the output to obtain convenient Centigrade scaling.

You can used this sensor for many projects, like fire prevention monitoring, weather forecasting, overheat monitor and many more.

STEP 1: Build Circuit

To build our circuit with Arduino Uno, follow the steps below:

1. Connect Arduino Uno GND to LM35 GND
2. Connect Arduino 5V pin to LM35 pin 1
3. Connect Arduino Uno Analog Pin 1 to LM35 pin OUT

STEP 2: Program and Read the Sensor

Download and open the attached source code on Arduino IDE.

Upload the sketch and read the sensor output on Serial Monitor

int pinTemp = A1;   //This is where our Output data goes

void setup() {
  Serial.begin(9600);     
}
void loop() {
  int temp = analogRead(pinTemp);    //Read the analog pin
  temp = temp * 0.48828125;   // convert output (mv) to readable celcius
  Serial.print("Temperature: ");
  Serial.print(temp);
  Serial.println("C");  //print the temperature status
  delay(1000);  
}

Once uploaded you will see the temperature status like this

Temperature: 29C

Temperature: 28C

Temperature: 29C

Temperature: 27.8C

Comments

[PadamveerS]

Can multiple Lm35's be used with this config?

[conradie.aj]

thank you for this.. but .. the output and program are not 100% correct. if you print an INT you will never get decimal point. a small change would be something like this:

int pinTemp = A1; //This is where our Output data goes
void setup() {
Serial.begin(9600);
}
void loop() {
int tempSensor = analogRead(pinTemp); //Read the analog pin
Serial.print("Temperature: sensor: ");
Serial.println(tempSensor);
float tempConverted = tempSensor * 0.48828125; // convert output (mv) to readable celcius
Serial.print("Temperature: converted: ");
Serial.print(tempConverted);
Serial.println(" C"); //print the temperature status
delay(1000);
}

[gassper.vaupot]

i used same code but as output i'm getting 475 C why???

[SomeRamdoOnline]

You might have your ground wire and power backwards, try swapping the ground and power wire