code.c

通过单片机模拟实现一个sin波形的输出。实现方式就是有pwm输出。

#include <pic.h>

#define	ADNUM	805

//base 0.
//const unsigned int Sin[100] = {0,1,2,4,6,9,12,16,20,25,30,35,41,48,55,63,71,79,88,97,106,116,127,138,149,160,172,184,197,209,223,236,250,263,278,292,306,321,336,351,367,382,398,413,429,445,461,477,493,509,524,540,556,572,588,604,619,635,650,666,681,696,711,725,739,754,767,781,794,808,820,833,845,857,868,879,890,901,911,920,929,938,946,954,962,969,976,982,987,992,997,1001,1005,1008,1011,1013,1015,1016,1017,1018};

//base 10
const unsigned int Sin[100] = {10,11,12,13,16,18,22,25,29,34,39,45,51,57,64,71,79,87,96,105,114,124,134,145,156,167,179,191,203,215,228,241,255,268,282,296,310,325,340,354,369,384,400,415,430,446,462,477,493,509,524,540,555,571,587,602,617,633,648,663,677,692,707,721,735,749,762,776,789,802,814,826,838,850,861,872,883,893,903,912,921,930,938,946,953,960,966,972,978,983,988,992,995,999,1001,1004,1005,1006,1007,1007};

// base 25.
//const unsigned int Sin[100] = {25,25,27,28,31,33,36,40,44,48,53,59,64,71,77,84,92,100,108,117,126,136,146,156,166,177,189,200,212,224,237,249,262,275,289,303,316,330,345,359,374,388,403,418,433,448,463,478,493,509,524,539,554,569,584,599,614,629,643,658,672,687,701,714,728,742,755,768,780,793,805,817,828,840,851,861,871,881,891,900,909,917,925,933,940,946,953,958,964,969,973,977,981,984,986,989,990,992,992,992};

//这是50的差值。
//const unsigned int Sin[100] = {50,51,52,53,55,58,61,64,68,72,77,82,87,93,100,106,114,121,129,137,146,155,164,174,184,194,205,216,227,239,251,263,275,287,300,313,326,340,353,367,381,394,408,423,437,451,465,480,494,509,523,537,552,566,580,594,609,623,636,650,664,677,691,704,717,730,742,754,766,778,790,801,812,823,833,843,853,862,871,880,888,896,903,911,917,924,930,935,940,945,949,953,956,959,962,964,965,967,967,968};

//base 100.
//const unsigned int Sin[100] = {100,100,101,103,105,107,109,112,116,120,124,128,133,139,144,150,157,163,170,178,185,193,202,210,219,229,238,248,258,268,279,289,300,312,323,334,346,358,370,382,394,407,419,432,445,457,470,483,496,509,521,534,547,560,572,585,598,610,623,635,647,659,671,683,694,705,717,728,738,749,759,769,779,788,798,807,815,824,832,839,847,854,860,867,873,878,884,889,893,897,901,905,908,910,912,914,916,917,917,917};

static unsigned int step;
unsigned long int longbuf;
unsigned int tempint;
unsigned char tempchar, datamul;
bit Fbit;

bit ADbit,ADFbit;
unsigned int ADdata,tempAD;
unsigned char ADmul,ADcnt;

unsigned int Rcnt;
unsigned int delay,delay2;

void main (void)
{
//-------------------------------------var initlize.
	step = 49;
	Fbit = 1;
	ADbit = 1;
	ADmul = 200;
	ADcnt = 0;
	Rcnt = 0;
	datamul = 200;						//must be low 255.
//-------------------------------------initlize.
	RB2 = 1;
	RC2 = 1;

	TRISC2 = 0;
	TRISC7 = 0;
	TRISC6 = 0;
	TRISA4 = 0;
	TRISA1 = 0;

	TRISB2 = 0;

	RB2 = 1;
	RC2 = 1;
//=============== COMPARE.
	CM1CON0 = 0x16;	
	
	CM2CON0 = 0x17;
	CM2CON1 = 0x32;
	
	SRCON = 0x00;						//...???
	VRCON = 0x00;						//??????
	
	C1IF = 0;
	C1IE = 0;
	C2IF = 0;
	C2IE = 0;
	
	C1ON = 0;
	C2ON = 0;
//=============== INT.
	TRISB0 = 1;
	
	INTEDG = 0;
	INTE = 0;
	INTF = 0;
//=============== AD.
	ANSEL = 0x08;
	TRISA3 = 1;
	ANSELH = 0x20;
	TRISB5 = 1;

	ADCON0 = 0xF4;
	ADCON1 = 0x90;
	ADIF = 0;
	ADIE = 0;
	ADON = 1;
		
//=============== TIMER2.PWM1.PWM2.
	TMR2 = 0;
	T2CON = 0x08;	
	PR2 = 251;				//251--> 100-> 50.1Hz;
	TMR2IF = 0;
	TMR2IE = 1;
	
	CCP1CON = 0x8F;			//ECCP1.
	PWM1CON = 0x0a;			//05 ---> 1uS, 04 ---> 0.8uS,06 ---> 1.2uS;
	ECCPAS = 0x55;			//过障保护。INT-->过流保护;
	PSTRCON = 0x13;			//PWM IO SET. and refresh Set.

	CCP2CON = 0x00;			//CCP2.
	CCPR2L = 0x80;

//================ COMP.
//	ANS2 = 1;	
//	ANS3 = 1;				//模拟输入电压参考端+5V。
//	ANS9 = 1;
//	ANS10 = 1;
	TRISA2 = 1;
	TRISA3 = 1;
	TRISB3 = 1;
	TRISB1 = 1;
	
	CM1CON0 = 0x07;
	CM2CON0 = 0x06;
	CM2CON1 = 0x30;	
	C1OE = 1;
	
	SRCON = 0x00;
	VRCON = 0x3C;			//外部参考电压分压调节
	VREN = 1;
	
	C1IE = 0;
	C2IE = 0;				//interrupt process.
	
	C1ON = 1;
	C2ON = 1;
	
// ================ 延时启动。
	delay = 0;
	delay2 = 0;
	while (1)
	{
		for (delay = 0; delay < 500; delay ++);
		if (C1OUT == 0)
			delay2 ++;
		else 
			delay2 = 0;
			
		if (delay2 > 5)
			break;
	}

	for (delay = 0; delay < 300; delay ++)
		for (delay2 = 0; delay2 < 6000; delay2 ++);		
		
	ECCPASE = 0;
	TMR2ON = 1;							//延时开启PWM。
		
//================= 中断.
	PEIE = 1;
	GIE = 1;
//-------------------------------------main code.
	while (1)
	{
		NOP();
//-------------------- AD processe.
		if (ADbit)
		{
			ADIF = 0;
			GODONE = 1;
			NOP();
			NOP();
			while (!ADIF);

			ADIF = 0;
			NOP();
			ADdata = ADRESH;
			ADdata <<= 8;
			ADdata += ADRESL;
/*
		if (ADdata > 900)
		{
			if (ADmul != 250)
				ADmul ++;
		}
		else
		{
			if (ADmul != 150)
				ADmul --;
		}
*/
			if (ADdata > ADNUM)
			{
				tempAD = ADdata - ADNUM;
				ADFbit = 1;
			}
			else 
			{
				tempAD = ADNUM - ADdata;
				ADFbit = 0;
			}
			
			
			if (tempAD > 3)					//5
			{
				if (ADFbit)
				{
					if (ADmul != 250)
						ADmul ++;
				}
				else 
				{
					if (ADmul != 150)
						ADmul --;
				}
			}

			ADbit = 0;
		}
//-------------------- R_Protect.
	if (C2OUT == 1)
	{
		RA1 = 0;
		if (Rcnt > 35000)
			ECCPASE = 1;		
	}
	else
	{
		RA1 = 1;
		Rcnt = 0;	
	}
	
//--------------------- other;
		NOP();
		NOP();

	}
}

void interrupt ISR (void)
{
	if (TMR2IE && TMR2IF)
	{
		TMR2IF = 0;
		RC7 = 1;		//for Test.
		if (Fbit)
		{
			step ++;
			if (step == 50)					//..
			{
				datamul = ADmul;			//refresh PWM datamul.
				ADcnt ++;
				//if (ADcnt == 2)
				{
					ADbit = 1;
					ADcnt = 0;
				}
			}
			if (step == 100)
			{
				Fbit = 0;
			}
		}
		else
		{
			step --;
			if (step == 1)
			{
				Fbit = 1;
			}
		}

		longbuf = Sin[step -1];

		if (step > 50)
		{
			longbuf = (longbuf - 509) * datamul;
			tempint = longbuf >> 8;
			tempint += 509;
		}	
		else
		{
			longbuf = (509 -longbuf) * datamul;
			tempint = longbuf >> 8;
			tempint = 509 - tempint;
		}

		//longbuf =longbuf * datamul;
		//tempint = longbuf >> 8;			//datamul <= 255;

		CCPR1L = tempint >> 2;
		tempchar = tempint;
		tempchar <<= 4;
		CCP1CON = (CCP1CON & 0xCF) | (tempchar & 0x30);

		Rcnt ++;
		RC7 = 0;			//for test.
	}

}