[PIC] PIC16f887 how to achieve 60HZ pwm frequency

[Tamim Neak]

i have made a little progress i changed the code to this

unsigned char sin_table[64]={0, 6, 12, 18, 24, 30, 36, 42, 48, 53, 59, 64, 69, 74, 79, 84, 88, 93, 97, 100, 104, 107, 110, 113, 115, 118, 120, 121, 123, 124, 124, 125, 125, 125, 124, 124, 123, 121, 120, 118, 115, 113, 110, 107, 104, 100, 97, 93, 88, 84, 79, 74, 69, 64, 59, 53, 48, 42, 36, 30, 24, 18, 12, 6};   //100% duty cycle

unsigned int TBL_POINTER_NEW, TBL_POINTER_OLD, TBL_POINTER_SHIFT, SET_FREQ;
unsigned int TBL_temp;
unsigned char DUTY_CYCLE;
unsigned int temp;

void interrupt(){
if (TMR2IF_bit == 1){
TBL_POINTER_NEW = TBL_POINTER_OLD + SET_FREQ;
if (TBL_POINTER_NEW < TBL_POINTER_OLD){
CCP1CON.P1M1 = ~CCP1CON.P1M1; //Reverse direction of full-bridge
                                        }
TBL_POINTER_SHIFT = TBL_POINTER_NEW >> 10;
DUTY_CYCLE = TBL_POINTER_SHIFT;
CCPR1L = sin_table[DUTY_CYCLE];
TBL_POINTER_OLD = TBL_POINTER_NEW;
TMR2IF_bit = 0;
                }
}
void Run_PWM(){
PORTC.F2 = 0;
PORTD.F5 = 0;
PORTD.F6 = 0;
PORTD.F7 = 0;
SET_FREQ = 1024;
TBL_POINTER_SHIFT = 0;
TBL_POINTER_NEW = 0;
TBL_POINTER_OLD = 0;
DUTY_CYCLE = 0;
PR2 = 0b01111100; //124
CCP1CON = 0b01001100; // duty lowest bits + PWM mode
TMR2IF_bit = 0;
T2CON = 4; //TMR2 on, prescaler and postscaler 1:1
while (TMR2IF_bit == 0);
TMR2IF_bit = 0;
TRISC = 0;
TMR2IE_bit = 1;
GIE_bit = 1;
PEIE_bit = 1;
}
void Stop_PWM(){
PORTC = 0;
PORTD = 0;
}


void main() {
ANSEL = 0; //Disable ADC
ANSELH = 0x00;
CM1CON0 = 0; //Disable Comparator
CM2CON0 = 0;
TRISD.F0 = 1;
TRISC.F2 = 0;
TRISD.F5 = 0;
TRISD.F6 = 0;
TRISD.F7 = 0;
TRISB.F0 = 0;
PORTC.F2 = 0;
PORTD.F5 = 0;
PORTD.F6 = 0;
PORTD.F7 = 0;
PORTB.F0 = 0;
PORTD.F0 = 0;
SET_FREQ = 1024;
TBL_POINTER_SHIFT = 0;
TBL_POINTER_NEW = 0;
TBL_POINTER_OLD = 0;
DUTY_CYCLE = 0;
PR2 = 0b01111100; //124
CCP1CON = 0b01001100; // duty lowest bits + PWM mode

do{
if (PORTD.F0==0){
   PORTB.F0 = 0;
   Stop_PWM();
        }
else {
   Run_PWM();
   PORTB.F0 = 1;
  }

}while(1);
}

now i have the folllowing issue i am getting

start of program

when i set the PORTB.F0 high

when i set the portb.f0 back to low

I want it to start with all 4 port as low then when PORTB.F0 is set high it should have wave form of picture 3 And when I set PORTB.F0 back to low all 4 pins should go low. I want the pwm to start from scratch whenever I set PORTB.F0 high.

 

[Tamim Neak]

i meant portd.f0 above.

 

[Tamim Neak]

the changes i made are wrong. i have chaged them again this time i am calling the enhanced pwm shutdown to stop the pwm and start it again here is the code.

unsigned char sin_table[64]={0, 6, 12, 18, 24, 30, 36, 42, 48, 53, 59, 64, 69, 74, 79, 84, 88, 93, 97, 100, 104, 107, 110, 113, 115, 118, 120, 121, 123, 124, 124, 125, 125, 125, 124, 124, 123, 121, 120, 118, 115, 113, 110, 107, 104, 100, 97, 93, 88, 84, 79, 74, 69, 64, 59, 53, 48, 42, 36, 30, 24, 18, 12, 6};   //100% duty cycle

unsigned int TBL_POINTER_NEW, TBL_POINTER_OLD, TBL_POINTER_SHIFT, SET_FREQ;
unsigned int TBL_temp;
unsigned char DUTY_CYCLE;
unsigned int temp;
char i;

void interrupt(){
if (TMR2IF_bit == 1){
TBL_POINTER_NEW = TBL_POINTER_OLD + SET_FREQ;
if (TBL_POINTER_NEW < TBL_POINTER_OLD){
CCP1CON.P1M1 = ~CCP1CON.P1M1; //Reverse direction of full-bridge
                                        }
TBL_POINTER_SHIFT = TBL_POINTER_NEW >> 10;
DUTY_CYCLE = TBL_POINTER_SHIFT;
CCPR1L = sin_table[DUTY_CYCLE];
TBL_POINTER_OLD = TBL_POINTER_NEW;
TMR2IF_bit = 0;
                }
}
void Run_PWM(){
PORTC.F2 = 0;
 PORTD.F5 = 0;
 PORTD.F6 = 0;
 PORTD.F7 = 0;
 SET_FREQ = 1024;
TBL_POINTER_SHIFT = 0;
TBL_POINTER_NEW = 0;
TBL_POINTER_OLD = 0;
DUTY_CYCLE = 0;
//ECCPAS = 0b00000101; //autoshutodwm disabled
PR2 = 0b01111100; //124
CCP1CON = 0b01001100; // duty lowest bits + PWM mode
TMR2IF_bit = 0;
T2CON = 4; //TMR2 on, prescaler and postscaler 1:1
while (TMR2IF_bit == 0);
TMR2IF_bit = 0;     // Timer2 interrupt flag
TRISC = 0;
TMR2IE_bit = 1;      //interrupt when TMR2 matches PR2
GIE_bit = 1;      // Global interrupt enabled
PEIE_bit = 1;     // peripheral interrupt enabled
ECCPAS =0b11000000;       //autoshutodwm on INT pin high
PWM1CON    = PWM1CON +   0b10000000  ;
}

void main() {
ANSEL = 0; //Disable ADC 
ANSELH = 0x00;
CM1CON0 = 0; //Disable Comparator
CM2CON0 = 0;
TRISC.F2 = 0;
TRISD.F5 = 0;
TRISD.F6 = 0;
TRISD.F7 = 0;
TRISB.F0 = 1;
 PORTC.F2 = 0;
 PORTD.F5 = 0;
 PORTD.F6 = 0;
 PORTD.F7 = 0;
  PORTB.F7 = 0;
  Run_PWM();

while(1);
 }

i have a new problem the pwm runs at the start of the program and starts responding to the portb.fo/int interrupt after the second time i set the portb.fo high. i want it to not run at the beginning and run after the first time i set the pin portb.fo high. please get back to me as soon as possible.