51单片机输出两路SPWM用于控制DC-AC半桥逆变电路工作的程序

本程序使用51单片机输出两路SPWM信号，用于控制DC-AC半桥逆变电路工作。其中，P1口输出SPWM1信号，P2口输出SPWM2信号。

程序代码如下：

#include <reg52.h>

sbit SPWM1 = P1^0; // SPWM1输出口
sbit SPWM2 = P2^0; // SPWM2输出口

unsigned char code sinTable[256] = { // 正弦波表
    128,131,134,137,140,143,146,149,152,155,158,161,165,168,171,174,
    177,180,183,186,189,192,195,198,201,204,207,210,212,215,218,221,
    223,226,229,232,234,237,239,242,244,247,249,251,253,255,257,259,
    261,263,265,267,269,271,273,274,276,278,279,281,282,284,285,287,
    288,289,291,292,293,294,296,297,298,299,300,301,302,303,303,304,
    305,306,306,307,307,308,308,308,309,309,309,309,309,309,309,309,
    309,309,309,308,308,308,307,307,306,306,305,304,303,303,302,301,
    300,299,298,297,296,294,293,292,291,289,288,287,285,284,282,281,
    279,278,276,274,273,271,269,267,265,263,261,259,257,255,253,251,
    249,247,244,242,239,237,234,232,229,226,223,221,218,215,212,210,
    207,204,201,198,195,192,189,186,183,180,177,174,171,168,165,161,
    158,155,152,149,146,143,140,137,134,131,128,125,122,119,116,113,
    110,107,104,101,98,95,91,88,85,82,79,76,73,70,67,64,61,
    58,55,52,49,47,44,42,39,37,34,32,30,28,26,24,22,20,
    18,16,14,12,10,8,6,5,3,2,1,0,0,0,0,0,0,
    0,0,0,0,1,2,3,5,6,8,10,12,14,16,18,20,22,
    24,26,28,30,32,34,37,39,42,44,47,49,52,55,58,61,64,
    67,70,73,76,79,82,85,88,91,95,98,101,104,107,110,113,116,
    119,122,125};

void delay(unsigned int n) // 延时函数
{
    unsigned int i, j;
    for (i = 0; i < n; i++)
        for (j = 0; j < 125; j++);
}

void main()
{
    unsigned char i = 0; // 正弦波表索引值
    while (1)
    {
        SPWM1 = (i < sinTable[i]); // SPWM1输出
        SPWM2 = (i >= sinTable[i]); // SPWM2输出
        i++;
        if (i == 255) // 索引值循环
            i = 0;
        delay(1); // 延时1ms
    }
}

在程序中，使用正弦波表来生成SPWM信号。使用while循环不断更新SPWM1和SPWM2的输出状态，以达到控制半桥逆变电路工作的目的。同时，使用delay函数来控制SPWM信号的频率，本程序中为1kHz。

需要注意的是，程序中的正弦波表是8位分辨率的，因此SPWM信号的精度也只有8位。如果需要更高的精度，可以使用更大的正弦波表，或使用浮点数计算正弦波。