用51单片机产生正弦波

用51单片机产生正弦波

单片机产生50Hz正弦波 1.实验要求

用单片机产生50Hz可调正弦波。 2.实验电路图

3.实验程序 #include #include

#define uchar unsigned char #define uint unsigned int #define DA_PORT XBYTE[0xf218] uchar code sin[256]={

0x80, 0x83, 0x86, 0x89, 0x8c, 0x8f, 0x92, 0x95, 0x98, 0x9c, 0x9f, 0xa2, 0xa5, 0xa8, 0xab, 0xae, 0xb0, 0xb3, 0xb6, 0xb9, 0xbc, 0xbf, 0xc1, 0xc4, 0xc7, 0xc9, 0xcc, 0xce, 0xd1, 0xd3, 0xd5, 0xd8, 0xda, 0xdc, 0xde, 0xe0, 0xe2, 0xe4, 0xe6, 0xe8,

0xea, 0xec, 0xed, 0xef, 0xf0, 0xf2, 0xf3, 0xf4, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfc, 0xfd, 0xfe, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xfe, 0xfd, 0xfc, 0xfc, 0xfb, 0xfa, 0xf9, 0xf8, 0xf7, 0xf6, 0xf5, 0xf3, 0xf2, 0xf0, 0xef, 0xed, 0xec, 0xea, 0xe8, 0xe6, 0xe4, 0xe3, 0xe1, 0xde, 0xdc, 0xda, 0xd8, 0xd6, 0xd3, 0xd1, 0xce, 0xcc, 0xc9, 0xc7, 0xc4, 0xc1, 0xbf, 0xbc, 0xb9, 0xb6, 0xb4, 0xb1, 0xae, 0xab, 0xa8, 0xa5, 0xa2, 0x9f, 0x9c, 0x99, 0x96, 0x92, 0x8f, 0x8c, 0x89, 0x86, 0x83, 0x80, 0x7d, 0x79, 0x76, 0x73, 0x70, 0x6d, 0x6a, 0x67, 0x64, 0x61, 0x5e, 0x5b, 0x58, 0x55, 0x52, 0x4f, 0x4c, 0x49, 0x46, 0x43, 0x41, 0x3e, 0x3b, 0x39, 0x36, 0x33, 0x31, 0x2e, 0x2c, 0x2a, 0x27, 0x25, 0x23, 0x21, 0x1f, 0x1d, 0x1b, 0x19, 0x17, 0x15, 0x14, 0x12, 0x10, 0x0f, 0x0d, 0x0c, 0x0b, 0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x03, 0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0c, 0x0d, 0x0e, 0x10, 0x12, 0x13, 0x15, 0x17, 0x18, 0x1a, 0x1c, 0x1e, 0x20, 0x23, 0x25, 0x27, 0x29, 0x2c, 0x2e, 0x30, 0x33, 0x35,

0x38, 0x3b, 0x3d, 0x40, 0x43, 0x46, 0x48, 0x4b, 0x4e, 0x51, 0x54, 0x57, 0x5a, 0x5d, 0x60, 0x63, 0x66, 0x69, 0x6c, 0x6f, 0x73, 0x76, 0x79, 0x7c, }; uint step =1; float a = 1.0; void delay(uint m); void sinwave(); void main() { while(1) {

sinwave(); } }

void delay(uint m) {

uint i , j;

for(i = 0; i < m; i++) for(j = 0; j < 120; j++); } void sinwave() { uchar t; uint i;

for(t= 0; t< 256; t= t+ 1)

{

for(i = 0 ; i < step ; i++) DA_PORT = (sin[t]*a); }

4.实验结果

将输出的模拟量接到示波器上，可调出频率为50Hz的正弦波;通过改变a和step值可改变输出波形的幅值和周期。