How Can Interface LM35, LM34 And LM335 Into  Arduino....?

In this 3rd article .I will show ,that "How Can Interface LM35, LM34 And LM335  Temperature Sensors Into  Arduino....?"Before this ,i have published two posts.If you want to visit for more information about Arduino projects.

1.LED BLINK ON ARDUINO BOARD WITH SIMPLE ARDUINO PROGRAMMING.

2.Anti Theft Detection From IR Sensor Using Arduino.

I will tell you, How to interface the LM35,LM34 or LM335 temperature sensors and write the code to receive the temperature readings and show on serial monitor.

What is LM35/LM34 Or LM335 Temperature Sensors?

The LM35, LM34 and LM335 are temperature measuring sensors.

That output analog voltage proportional to the temperature.

S.N.   Temperature Sensor        Output Voltage              Linearity

  1.        LM35                Analog Output Voltage                   10-mv/C

                                         Proportional to Temperature      

                                                             In               

                                                     Celsius( C )             

 2.        LM34                  Analog Output Voltage                  10-mv/F

                                         Proportional to Temperature      

                                                             In                                         

                                                     Fahrenheit(F)                       

 3.        LM335                     Analog Output Voltage             10-mv/K

                                       Proportional to Temperature      

                                                            In                                         

                                                     Kelvin(K)    

       

The   LM35 Temperature sensor is output voltage provide in centigrade (0C) in temperature and also LM34 analog output voltage in Fahrenheit (0F) and LM335 is output voltage provide in Kelvin unit, all these temperature sensor are different different output voltage provide in unit. These sensors are not need any external circuit for calibration.

For Example:- If the LM35 analog output voltage is 100-mv/c, That means 10C of                                       Temperature value .   

If you want to know more information about this Temperature sensor. You can read their data sheet.

1.LM35(LM35DZ) Data Sheets With Link.

2.LM34 Data Sheets Sheets With Link.

3.LM335 Data Sheets With LInk.     

Pin out of LM35/LM34

There are Three pins Vcc   , Vout    and GND of LM35 And LM34 Temperature sensor.

                                        

                                         

LM35/LM34

VCC  -    Supply Voltage (5v - 40v)

Vout   -    It gives analog output voltage who proportional to the temperature in (0C)               

                                                   

GND  -      Common    

Here LM35/LM34 Interface to Arduino.

LM35/LM34               ArduinoUno  

Vcc                    -          5v

                                                            

GND                 -          GND Or Common  

Vout                  -          Analog Pin

Here the LM335 temperature sensor is different from LM35 and LM35 sensor. 

Here LM335 Interface to Arduino.

LM335                   ArduinoUno  

Adj            -            No Connect

                                                            

GND         -             GND Or Common  

Vout          -             Analog Pin with Pull up resistor 2k Ohm

Here Adj can be used calibrated for more accuracy temperature.But here Adj pin of LM335 is not connect. I am only using Vout pin of LM335 with 2k ohm pull up resistor.

Schematic Diagram Of Temperature Sensor From the Frizzing  

         

Here following code to readings the temperature from the LM 35 or LM34 sensor and Display on the serial monitor and you will un comment following code for LM335. When you will Read temperature from the LM335 Temperature sensor. 
Code:-

       int   LM35  = A0;

       float LM35_var;

       float Vout;

       float TempC;

       float TempF;

    //float TempK;  //uncomment When you will use LM335

      

  void setup()

     {

       Serial.begin( 9600 );

       pinMode( LM35, INPUT );

     }

void loop()

    {

        LM35_var  =  analogRead( LM35 );

       Vout          =  ( LM_var * 5000 )/1023;

//For LM35

        TempC     =  Vout/10;

        TempF    =  (TempC * 1.8) + 32;

//For LM34

  //      TempF  = Vout/10;

  //      TempC  = (TempF - 31.0) * (5.0/9.0);

//For LM335

 //       TempK = Vout/10;

//        TempC = TempK - 272;

//        TempF = ( TempC * 1.8 ) + 32;

        

        Serial.Print(" Vout = ");

        Serial.println( Vout );

        Serial.Print(" Temperature = ");

        Serial.println( TempC );

        Serial.Print("Fahrenheit= ");

        Serial.println( TempF);

        delay(500);

}