mikroc program pulse width modulation

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Now lets see how to write a code using the mikroc compiler to control the pwm module .
For your convenience MikroC provides PWM library and there are 4 functions present in

• Pwm_Init
• Pwm_Change_Duty
• Pwm_Start
• Pwm_Stop

The pwm_init takes a arguement of frequency in hertz

To Initialize a PWM module at 5KHz do this :Pwm_Init(5000);

Pwm_Start and Pwm_Stop are self explanatory I guess .These functions doesnt take any arguements .

Pwm_Change_Duty Changes PWM duty ratio. Parameter duty takes values from 0 to 255, where 0 is 0%, 127 is 50%, and 255 is 100% duty ratio. Other specific values for duty ratio can be calculated as (Percent*255)/100.

Take a look at the following simple program

void main (){
portb = 0x00 ; //clear portb
TRISB = 0xFF ; //Set PortB as input
PORTC = 0x00; // clear PORTC 
TRISC = 0; // PORTC is output
Pwm1_Init(5000); // Initialize PWM modulen set frequency as 5000
Pwm1_Start(); //Start the pwm module
while(1){
if (portb==0x80) //if rc7 is high
Pwm_Change_Duty(127); //set the duty cycle as 50%

}
}

This program creates a pwm on pin17 of PIC16F877A .

Hope you found this tutorial useful .If you have any doubts about the program .Leave a comment .