Light Emitting Register & Temperature Sensor LM35

ADC / By /

In this program we use an LDR to read the light condition. The connection diagram of LDR as follow-

LDR is nothing but a register that vary with light condition. At low light resistance is high and at high light the resistance is low. Temperature sensor LM35 is a digital temperature whose Vout value change according to temperature. The sensor has reading +10mV/°C. Since our ADC has a resolution 5/1024=4.88mV so the desire temperature is

The main program-

  #include<avr/io.h>
  #include<stdio.h>
  #include<util/delay.h>
  #include"adc.h"
  #include"lcd.h"
  uint16_t value,tempa;
  float temperature;
  char str[20];
int main(void)
  {
   LCD_INIT();
   adc_init();
   LCD_Clear();
   DDRB|=(1<<DDB1);                     //LOAD PORT
   _delay_ms(10);
   LCD_Clear();
   while(1)
   {
     value=read_adc(0);
     tempa=read_adc(1);
     temperature=(tempa*4.88)/10;
     sprintf(str,"%d   %.2f",value,temperature);
     if(value<=400)
	    {
	      PORTB |=(1<<PINB1);			 //in dark condition glow
	    }else{
	      PORTB &=~(1<<PINB1);			 //else off
	    }
     LCD_write_string(1,1,"ADC  Temperature");
     LCD_write_string(1,2,str);
   }
 return 0;
}

Read all dark condition of light and your desire condition inside if loop. For proper connection diagram see the proteus simulation.

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Sensor clibration.rar