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Title: Pulse Width Mudulation(PWM)
Description: explanation and code for generating a pwm square wave with variable duty cycle in 8051 or any other micro controller. explained with softwares used and snapshots
Description: explanation and code for generating a pwm square wave with variable duty cycle in 8051 or any other micro controller. explained with softwares used and snapshots
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PULSE WITH MODULATION
OBJECTIVE:
The objective is to generate a pulse of constant time period on a certain pin of 8051
Microcontroller and to increase and decrease the duty cycle of the generated pulse using two
control push buttons such that its time period remains unchanged
...
The code is as
follows:
#include
h>
sbit pulse = P1^0;
sbit inc = P2^0;
sbit dec = P2^1;
void msdelay(int);
main()
{
int i=200;
int j=200;
int D=0x50;
P3=D;
do
{
pulse=1;
msdelay(i);
pulse=0;
msdelay(j);
}
while(inc==0 && dec==0);
check_again:
if(inc==1 && dec==0)
{
while(inc==1 && dec==0)
{
if(inc==1 && dec==0)
{i=i+20; j=j-20; D=D+0x10; P3=D;}
else if(inc==0 && dec==1)
{i=i-20; j=j+20; D=D-0x10; P3=D;}
else
{i=i; j=j;}
do
{
pulse=1;
msdelay(i);
pulse=0;
msdelay(j);
}
while(inc==0 && dec==0);
}
//////// while 1 closed
goto check_again;
}
//////// if closed
else
{
while(inc==0 && dec==1)
{
if(inc==0 && dec==1)
{i=i-20; j=j+20; D=D-0x10; P3=D; }
else if(inc==1 && dec==0)
{i=i+20; j=j-20; D=D+0x10; P3=D;}
else
{i=i; j=j;}
do
{
pulse=1;
msdelay(i);
pulse=0;
msdelay(j);
}
while(inc==0 && dec==0);
}
/////// while 2 closed
goto check_again;
//////// else closed
}
//////// main closed
///////////////// delay function//////////////////
void msdelay(int time)
{
int x,y;
for(x=0; x
}
The I write the C language code in Kiel Software and compiled it to generate the required HEX
file
...
The simulated circuit is shown in the figure below
...
While at the same time the resulting duty cycle can also be observed on the
7-segment display as shown in the figure above
...
Title: Pulse Width Mudulation(PWM)
Description: explanation and code for generating a pwm square wave with variable duty cycle in 8051 or any other micro controller. explained with softwares used and snapshots
Description: explanation and code for generating a pwm square wave with variable duty cycle in 8051 or any other micro controller. explained with softwares used and snapshots