humidity

[bharat]

wat r the basic used ..of using microcontroller for sensing humidity?

 

 

can any simplified that following code or tel me wat these is all about…

 

 

/ Program to Interface Humidity sensor with 8051 Microcontroller

#include<reg51.h>

sfr lcd_data_pin=0x80;//p0 port

sbit rs=P3^0;

sbit rw=P3^1;

sbit en=P3^2;

sbit wr= P3^3;

sbit rd= P3^4;

sbit intr= P3^5;

sfr input_port=0x90; //p1 port

unsigned int number=0;

unsigned char humidity,lcd,key=0;

 

void delay(unsigned char count)

{

unsigned char i;

unsigned int j;

for(i=0;i<count;i++)

for(j=0;j<1275;j++);

}

 

void lcd_command(unsigned char comm)

{

lcd_data_pin=comm;

en=1;

rs=0;

rw=0;

delay(1);

en=0;

}

 

void lcd_data(unsigned char disp)

{

lcd_data_pin=disp;

en=1;

rs=1;

rw=0;

delay(1);

en=0;

}

 

lcd_dataa(unsigned char *disp)

{

unsigned char x;

for(x=0;disp[x]!=0;x++)

{

lcd_data(disp[x]); 

}

}

 

void lcd_ini()

{

lcd_command(0x38);  // for using 8-bit 2 row LCD 

delay(50);

lcd_command(0x0F);        // for display on cursor blinking

delay(50);

lcd_command(0x0C);

delay(50);

lcd_command(0x80);

delay(50);

}

 

void lcd_display(unsigned int val)

{  

unsigned char flg=0;

lcd_command(0xC7);

if(val==0)

lcd_data(‘0’);

while(val>0)

{  

lcd=val%10;

val=val/10;

lcd_command(0xC7-flg);

lcd_data(lcd+’0′);

flg++;  

}

  

}

 

void display()

{

key++;

number=number+input_port;

if(key==11)

{

number=number/key;

number=number*10;

number=number/25;

humidity=number-3;

lcd_display(humidity);

key=0;

number=0;

}

}

 

void adc()

{

rd=1;

wr=0;

delay(2);

wr=1;

while(intr==1);

rd=0;

display();

delay(2);

intr=1;

}

 

void main()

{

lcd_ini();

lcd_dataa(“%Rel.Humidity:”);

while(1)

{

adc();

}

}

[GANEEV SINGH]

Hi

This code is written in order to read a sensor value (must be a humidity sensor here) and display "Rel.Humidity" on a LCD. 

In this code average of 11 consecutive sensor readings is made and then it is converted to relative humidity value by means of some sort of a formula. This all is happening inside display() function.

Since 8051's don't have inbuilt ADCs therefore an 8 bit ADC IC must be connected to it with PORT1.

[Author]

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