Jump to content

Lucian

Members
  • Content Count

    2
  • Joined

  • Last visited

Community Reputation

0 Neutral

About Lucian

  • Rank
    Newbrie
  1. I think we don't have. You can make your own function. I have a sample code made long back. see if it can help u. Its made for PIC16F72, 1mhz RC clock. #include <system.h> // Set clock frequency to 1MHz. #pragma CLOCK_FREQ 1000000 //set configuration fuse. #pragma DATA _CONFIG, _RC_OSC & _WDT_OFF & _CP_OFF & _PWRTE_OFF int duty_cycle; //global variable /*Interrupt service routine (ISR).On timer2 interrupt, program will jump to this code location. */ void interrupt( void ) { char pulse; /*generate two 50hz 180 degree out of phase pulses & externally AND it with the 100Hz pwm pin to get a modulated 50Hz to drive mosfets connected to a transformer in a push-pull configuration. A/D conversion of the the output voltage can act as feed back to adjust the duty-cycle ( not yet implemented in this code). */ pulse = portb; pulse.0 = ~ pulse.0; pulse.1 = ~ pulse.1; portb = pulse; pir1.1=0; //clear TMR2 to pr2 match interrupt flag } void load_duty_cycle(void) { ccpr1l.7 = duty_cycle.9; ccpr1l.6 = duty_cycle.8; ccpr1l.5 = duty_cycle.7; ccpr1l.4 = duty_cycle.6; ccpr1l.3 = duty_cycle.5; ccpr1l.2 = duty_cycle.4; ccpr1l.1 = duty_cycle.3; ccpr1l.0 = duty_cycle.2; ccp1con.5 = duty_cycle.1; ccp1con.4 = duty_cycle.0; } // The main code configures the pwm registers void main() { trisa = 255; trisb = 0; //configure port B as output trisc = 0; // portc as out put portb = 1; //set port B to 1 portc = 0; //clear portc // enable interrupts intcon.6=1; //enable peripheral interrupt intcon.7=1; //enable global interrupt pie1.1=1; //tmr2 to pr2 match interrupt //configure the ccp1con register to enable PWM module. /*ccpxm3:ccpxm0: mode select bits<3:0> 11xx = for PWM mode. */ ccp1con=0b00001100; // //PWM period=[(PR2)+1]*4*Tosc*(TMR2 prescaler value) /*our pmw period is 10ms(100Hz),Tosc is 1/1000,000Hz & prescaler is 16.For which PR2+1 works out to 156.25. Lets round it to 156 & make PR2 to 155. */ //load the period value into pr2 register. pr2 = 155; /*timer2 control register we have selected bit6-3...(0000) 1:1 for post scaler bit2.....(1) timer2 on bit1-0...(11) prescaler is 16 */ t2con = 0b00000111; /*PWM duty cycle = (ccpr1l:ccp1con<5:4>)*Tosc*(TMR2 prescaler value) Here i have taken 2ms as an example value for duty cycle, Tosc & pre- scaler are same as above.We will get 10 bit values when we work with larger duty cycle but for our example we get the value as 125. */ //load the duty cycle values while( 1 ) { int b0; for(b0=1;b0<563;b0++) { duty_cycle = b0; load_duty_cycle(); delay_ms(9); } } } Regards Raghunathan
  2. Are there functions in Sourceboost C Compiler for PWM?
×
×
  • Create New...