A Major project on

DIGITAL WATTMETER

-S.SRAVANKUMARREDDY (11B91A04A5)-R.ARJUNBABU (11B91A04A0)-S.VAMSHIKRISHNAREDDY (11B91A04A1)

WHAT IS digital WATTMETER ?

The wattmeter is an instrument for measuring the electric power or the supply rate

of electrical energy in watts of any given circuit. Electromagnetic wattmeter s are used

for measurement of utility frequency and audio frequency power; other types are

required for radio frequency measurements.

What is digital voltmeter?

Digital Voltmeters (DVMs) are a special case of A/Ds.

DVMs are voltmeters - i.e. they measure voltage - and are general

purpose instruments commonly used to measure voltages in labs

and in the field. DVMs display the measured voltage using LCDs

or LEDs to display the result in a floating point format.

What is digital ammeter ?

Ammeter, instrument for measuring either direct or alternating electric

current, in amperes. An ammeter can measure a wide range of current values

because at high values only a small portion of the current is directed through

the meter mechanism; a shunt in parallel with the meter carries the major

portion.

PROGRAM of digital wattmeter

sbit LCD_RS at RB0_bit;

sbit LCD_EN at RB1_bit;

sbit LCD_D4 at RB2_bit;

sbit LCD_D5 at RB3_bit;

sbit LCD_D6 at RB4_bit;

sbit LCD_D7 at RB5_bit

sbit LCD_RS at RB0_bit;

sbit LCD_EN at RB1_bit;

sbit LCD_D4 at RB2_bit;

sbit LCD_D5 at RB3_bit;

sbit LCD_D6 at RB4_bit;

sbit LCD_D7 at RB5_bit

sbit button1 at RD0_bit;

sbit button2 at RD1_bit;

sbit button3 at RD2_bit;

sbit device1 at RC0_bit;

sbit device2 at RC1_bit;

sbit device3 at RC2_bit;

unsigned char byte[]="0123456789";

unsignedint temp,temp1,i1,i2;

unsignedint w1;

char a;

sbit buzzer at RD4_bit;

void main()

{

TRISD0_bit=TRISD1_bit=TRISD2_bit=1;

TRISD5_bit=TRISD6_bit=TRISD7_bit=0;

TRISC0_bit=0;

device1=device2=device3=1;

delay_ms(300);

device1=device2=device3=0;

buzzer=0;

button1=button2=button3=1;

LCD_init();

ADC_init();

LCD_cmd(_LCD_clear);

LCD_cmd(_lcd_cursor_off);

lcd_out(1,9,"Imax=90");

lcd_out(2,10,"Wm=1090");

delay_ms(100);

while(1)

{

lcd_out(1,9,"Imax=90");

lcd_out(2,10,"Wm=1090");

if(button1==0)

{

while(button1==0);

device1=~device1;

}

if(button2==0)

{

while(button2==0);

device2=~device2;

}

if(button3==0)

{

while(button3==0);

device3=~device3;

}

i1=ADC_read(1);

i1=i1/1.80;

i1=i1*10;

if(i1<90)

{

lcd_chr(1,1,'I');

lcd_chr(1,2,'=');

lcd_chr(1,3,byte[i1/100%10]);

lcd_chr(1,4,byte[i1/10%10]);

lcd_chr(1,5,byte[i1%10]);

lcd_chr(1,6,'m');

lcd_chr(1,7,'A');

w1=12.1*i1;

w1=w1*10;

lcd_chr(2,1,'W');

lcd_chr(2,2,'=');

lcd_chr(2,3,byte[w1/10000%10]);

lcd_chr(2,4,byte[w1/1000%10]);

lcd_chr(2,5,byte[w1/100%10]);

lcd_chr(2,6,byte[w1/10%10]);

lcd_chr(2,7,'m');

lcd_chr(2,8,'W');

delay_ms(100);

}

if(i1>95)

{

w1=i1*12.1;

lcd_chr(1,3,byte[i1/100%10]);

lcd_chr(1,4,byte[i1/10%10]);

lcd_chr(1,5,byte[i1%10]);

lcd_chr(2,3,byte[w1/1000%10]);

lcd_chr(2,4,byte[w1/100%10]);

lcd_chr(2,5,byte[w1/10%10]);

lcd_chr(2,6,byte[w1%10]);

delay_ms(1000);

LCD_cmd(_lcd_clear);

LCD_out(1,1,"Overload Occurs ");

LCD_out(2,1,"Devices Turn OFF");

for(a=0;a<12;a++)

{

buzzer=1;

delay_ms(100);

buzzer=0;

delay_ms(100);

device1=device2=device3=0;

}

LCD_cmd(_lcd_clear);

}

}}

Circuit diagram of digital wattmeter