軟件實現(xiàn)雙極性SPWM

PWM正弦波發(fā)生器:

#include //config1__CONFIG (FOSC_HS & WDTE_OFF & MCLRE_OFF & CP_OFF & BOREN_OFF);//confing2//__CONFIG (PLLEN_ON); //OSC*4 = 32 MHz__CONFIG (PLLEN_OFF); //OSC = 8 MHzconst unsigned int pwmtab[]={0x80,0x86,0x8C,0x92,0x98,0x9E,0xA4,0xA9,0xAF,0xB4,0xBA,0xBF,0xC4,0xC9,0xCE,0xD3,0xD7,0xDB,0xDF,0xE3,0xE7,0xEA,0xED,0xF0,0xF3,0xF5,0xF8,0xFA,0xFB,0xFC,0xFE,0xFE,0xFF,0xFF,0xFF,0xFF,0xFE,0xFD,0xFC,0xFA,0xF9,0xF7,0xF4,0xF2,0xEF,0xEC,0xE9,0xE5,0xE1,0xDD,0xD9,0xD5,0xD0,0xCC,0xC7,0xC2,0xBC,0xB7,0xB2,0xAC,0xA6,0xA1,0x9B,0x95,0x8F,0x89,0x83,0x7D,0x77,0x71,0x6B,0x65,0x5F,0x5A,0x54,0x4E,0x49,0x44,0x3E,0x39,0x34,0x30,0x2B,0x27,0x23,0x1F,0x1B,0x17,0x14,0x11,0x0E,0x0C,0x09,0x07,0x06,0x04,0x03,0x02,0x01,0x01,0x01,0x01,0x02,0x02,0x04,0x05,0x06,0x08,0x0B,0x0D,0x10,0x13,0x16,0x19,0x1D,0x21,0x25,0x29,0x2D,0x32,0x37,0x3C,0x41,0x46,0x4C,0x51,0x57,0x5C,0x62,0x68,0x6E,0x74,0x7A};

void PWM1(void){ #define FOSC 8000000.0 //系統(tǒng)時間頻率8M, #define DIV 1.0 //timer2預(yù)分頻 //#define DIV 4.0 //timer2預(yù)分頻 //#define DIV 16.0 //timer2預(yù)分頻 #define FPWM 20000.0 //PWM頻率 20k(spwm) #define PWM_PERIOD 1000000.0/FPWM //PWM周期 50us #define TOSC 1000000.0/(FOSC) //機器周期 0.125US //4TOSC = 0.125US*4 = 0.5us #define PR2_LOADER (PWM_PERIOD-(4*TOSC*DIV)) / (4*TOSC*DIV) RB3 = 0; TRISB3 = 0; RB5 = 0; TRISB5 = 0; CCPTMRS = 0; CCP1CON = 0x8c; CCP1CON &= ~(0x03<<4); CCPR1L=0x00; TMR2 = 0; T2CON = 0x00;//預(yù)分頻1:1 PR2 = 99; PWM1CON = 0x02;//死區(qū)時間1us (FOSC/4（4 * TOSC）) TMR2IF = 0; //Timer2 與PR2 匹配中斷標(biāo)志位 TMR2IE = 1; // TMR2 與PR2 匹配中斷允許位 T2CON |= (1<<2)|(0x02<<3); }

void main(){ for (i=0; i<255; i++); PWM1(); INTCONbits.GIE = 1; INTCONbits.PEIE = 1; TRISBbits.TRISB0 = 0; PORTBbits.RB0 = 0; while(1) { }}void interrupt isr(void){ static unsigned char index; unsigned int reference; if (TMR2IE && TMR2IF) { TMR2IF = 0; PORTBbits.RB0 = !PORTBbits.RB0; reference = pwmtab[index]; CCPR1L = (reference>>2)&0xff; //CCP1CON &= ~(0x03<<4); //CCP1CON |= ((reference&0xff)<<4); if (++index > 66*2) { index = 0; } }}

看了N天理論，不如動手一試！

呵呵, 結(jié)果！