输出1HZ正弦波、三角波、方波、锯齿波
使用LCD1602显示
DAC0832的D0~D7数据输入口，IOUT1、IOUT2互补输出口，RFB反馈端口、
VREF基准电压值（一般是5V）。用定时器控制段码表输出速度来控制波形的频率。
（定时数值)*10^(-6)*256=波形频率。
（1）锯齿波的实现原理：锯齿波的实现过程是首先定义一个初值然后进行加法操作，加的步数的多少则根据要求的频率来进行。然后加到某个数之后就再重新设置为初值，再重复执行刚刚的操作，如此循环下去。在本程序中初值为00H，最大值为FFH。
（2）三角波的实现原理：三角波的实现是设置一个初值，然后进行加数，同样是加到某个数之后再进行减数，减到初值之后就再返回到先前的操作。此程序输入的VREF的电压是＋5V，因此该波形输出的最大频率是初值为00H和最终值为FFH，且步数为1，这样输出的波形是最大的。
（3）方波的实现原理：此波形的实现只需开始的时候设置一个初值然后直接输出这个值就行了，输出一段时间后，然后再重新置一个数据，然后再输出这个数据一段时间，但是此时的时间一定要等于前面那段时间。这样才是一个方波，如果两个时间不相同，那就相当于一个脉冲波了。
主函数和中断服务函数
#include <REGX52.H>#include <Delay.h>#include <LCD1602.h>#include <data.h>#include "Timer0.h"#define BO P3#define KEY0 P1_0#define KEY1 P1_1#define KEY2 P1_2#define KEY3 P1_3#define KEY4 P1_4unsigned int Number=1,Signal_chose=0,n=0,THHL,x,i;unsigned int freq=3906;void main(){Timer0Init();LCD_Init();while(1){//if(KEY4==0)//{//Delay(20);//while(KEY4==0);//Delay(20);//freq=freq/10;//Number=Number*10;//}if(KEY0==0){TF0 = 0;LCD_ShowString(1,1,"sin:");LCD_ShowString(2,1,"FREQ:");LCD_ShowNum(2,8,Number,3);LCD_ShowString(2,11,"Hz");TR0 = 1;Signal_chose=0;}if(KEY1==0){TF0 = 0;LCD_ShowString(1,1,"squ:");LCD_ShowString(2,1,"FREQ:");LCD_ShowNum(2,8,000,3);LCD_ShowString(2,11,"Hz");TR0 = 1;Signal_chose=2;}if(KEY2==0){TF0 = 0;LCD_ShowString(1,1,"thr:");LCD_ShowString(2,1,"FREQ:");LCD_ShowNum(2,8,Number,3);LCD_ShowString(2,11,"Hz");TR0 = 1;Signal_chose=1;}if(KEY3==0){TF0 = 0;LCD_ShowString(1,1,"jch:");LCD_ShowString(2,1,"FREQ:");LCD_ShowNum(2,8,Number,3);LCD_ShowString(2,11,"Hz");TR0 = 1;Signal_chose=3;}switch(Signal_chose) { case 0: {BO=sin[n]; break;} //正弦波case 1: {BO=thr[n]; break;} //三角波case 2: {for(i=0;i<256;i++){BO=squ[i];}break;} //方波case 3: {BO=256-n;break;}//锯齿波default:{break;} }}}void Timer0_Routine() interrupt 1{THHL=65536-freq;//(freq=3906)*10^(-6)*256=1HzTL0=THHL%256;TH0=THHL/256; if(n>=255) {n=0;} else {n++;} }
LCD显示函数
#include <REGX52.H>//引脚配置：sbit LCD_RS=P2^0;sbit LCD_RW=P2^1;sbit LCD_EN=P2^2;#define LCD_DataPort P0//函数定义：/*** @brief LCD1602延时函数，12MHz调用可延时1ms* @param 无* @retval 无*/void LCD_Delay(){unsigned char i, j;i = 2;j = 239;do{while (--j);} while (--i);}/*** @brief LCD1602写命令* @param Command 要写入的命令* @retval 无*/void LCD_WriteCommand(unsigned char Command){LCD_RS=0;LCD_RW=0;LCD_DataPort=Command;LCD_EN=1;LCD_Delay();LCD_EN=0;LCD_Delay();}/*** @brief LCD1602写数据* @param Data 要写入的数据* @retval 无*/void LCD_WriteData(unsigned char Data){LCD_RS=1;LCD_RW=0;LCD_DataPort=Data;LCD_EN=1;LCD_Delay();LCD_EN=0;LCD_Delay();}/*** @brief LCD1602设置光标位置* @param Line 行位置，范围：1~2* @param Column 列位置，范围：1~16* @retval 无*/void LCD_SetCursor(unsigned char Line,unsigned char Column){if(Line==1){LCD_WriteCommand(0x80|(Column-1));}else if(Line==2){LCD_WriteCommand(0x80|(Column-1+0x40));}}/*** @brief LCD1602初始化函数* @param 无* @retval 无*/void LCD_Init(){LCD_WriteCommand(0x38);//八位数据接口，两行显示，5*7点阵LCD_WriteCommand(0x0c);//显示开，光标关，闪烁关LCD_WriteCommand(0x06);//数据读写操作后，光标自动加一，画面不动LCD_WriteCommand(0x01);//光标复位，清屏}/*** @brief 在LCD1602指定位置上显示一个字符* @param Line 行位置，范围：1~2* @param Column 列位置，范围：1~16* @param Char 要显示的字符* @retval 无*/void LCD_ShowChar(unsigned char Line,unsigned char Column,char Char){LCD_SetCursor(Line,Column);LCD_WriteData(Char);}/*** @brief 在LCD1602指定位置开始显示所给字符串* @param Line 起始行位置，范围：1~2* @param Column 起始列位置，范围：1~16* @param String 要显示的字符串* @retval 无*/void LCD_ShowString(unsigned char Line,unsigned char Column,char *String){unsigned char i;LCD_SetCursor(Line,Column);for(i=0;String[i]!='\0';i++){LCD_WriteData(String[i]);}}/*** @brief 返回值=X的Y次方*/int LCD_Pow(int X,int Y){unsigned char i;int Result=1;for(i=0;i<Y;i++){Result*=X;}return Result;}/*** @brief 在LCD1602指定位置开始显示所给数字* @param Line 起始行位置，范围：1~2* @param Column 起始列位置，范围：1~16* @param Number 要显示的数字，范围：0~65535* @param Length 要显示数字的长度，范围：1~5* @retval 无*/void LCD_ShowNum(unsigned char Line,unsigned char Column,unsigned int Number,unsigned char Length){unsigned char i;LCD_SetCursor(Line,Column);for(i=Length;i>0;i--){LCD_WriteData(Number/LCD_Pow(10,i-1)%10+'0');}}/*** @brief 在LCD1602指定位置开始以有符号十进制显示所给数字* @param Line 起始行位置，范围：1~2* @param Column 起始列位置，范围：1~16* @param Number 要显示的数字，范围：-32768~32767* @param Length 要显示数字的长度，范围：1~5* @retval 无*/void LCD_ShowSignedNum(unsigned char Line,unsigned char Column,int Number,unsigned char Length){unsigned char i;unsigned int Number1;LCD_SetCursor(Line,Column);if(Number>=0){LCD_WriteData('+');Number1=Number;}else{LCD_WriteData('-');Number1=-Number;}for(i=Length;i>0;i--){LCD_WriteData(Number1/LCD_Pow(10,i-1)%10+'0');}}/*** @brief 在LCD1602指定位置开始以十六进制显示所给数字* @param Line 起始行位置，范围：1~2* @param Column 起始列位置，范围：1~16* @param Number 要显示的数字，范围：0~0xFFFF* @param Length 要显示数字的长度，范围：1~4* @retval 无*/void LCD_ShowHexNum(unsigned char Line,unsigned char Column,unsigned int Number,unsigned char Length){unsigned char i,SingleNumber;LCD_SetCursor(Line,Column);for(i=Length;i>0;i--){SingleNumber=Number/LCD_Pow(16,i-1)%16;if(SingleNumber<10){LCD_WriteData(SingleNumber+'0');}else{LCD_WriteData(SingleNumber-10+'A');}}}/*** @brief 在LCD1602指定位置开始以二进制显示所给数字* @param Line 起始行位置，范围：1~2* @param Column 起始列位置，范围：1~16* @param Number 要显示的数字，范围：0~1111 1111 1111 1111* @param Length 要显示数字的长度，范围：1~16* @retval 无*/void LCD_ShowBinNum(unsigned char Line,unsigned char Column,unsigned int Number,unsigned char Length){unsigned char i;LCD_SetCursor(Line,Column);for(i=Length;i>0;i--){LCD_WriteData(Number/LCD_Pow(2,i-1)%2+'0');}}
定时器配置函数
#include <REGX52.H>extern unsigned int freq;void Timer0Init(void){unsigned int THHL;TMOD &= 0xF0;//设置定时器模式TMOD |= 0x01;//设置定时器模式THHL=65536-freq;TL0 =THHL%256;//设置定时初值TH0 =THHL/256;//设置定时初值TF0 = 0;//清除TF0标志TR0 = 1;//定时器0开始计时ET0=1;EA=1;PT0=0; }
波形段码表
#ifndef _DATA_H#define _DATA_Hunsigned code sin[256]={ 0x80,0x83,0x85,0x88,0x8A,0x8D,0x8F,0x92, 0x94,0x97,0x99,0x9B,0x9E,0xA0,0xA3,0xA5, 0xA7,0xAA,0xAC,0xAE,0xB1,0xB3,0xB5,0xB7, 0xB9,0xBB,0xBD,0xBF,0xC1,0xC3,0xC5,0xC7, 0xC9,0xCB,0xCC,0xCE,0xD0,0xD1,0xD3,0xD4, 0xD6,0xD7,0xD8,0xDA,0xDB,0xDC,0xDD,0xDE, 0xDF,0xE0,0xE1,0xE2,0xE3,0xE3,0xE4,0xE4, 0xE5,0xE5,0xE6,0xE6,0xE7,0xE7,0xE7,0xE7, 0xE7,0xE7,0xE7,0xE7,0xE6,0xE6,0xE5,0xE5, 0xE4,0xE4,0xE3,0xE3,0xE2,0xE1,0xE0,0xDF, 0xDE,0xDD,0xDC,0xDB,0xDA,0xD8,0xD7,0xD6, 0xD4,0xD3,0xD1,0xD0,0xCE,0xCC,0xCB,0xC9, 0xC7,0xC5,0xC3,0xC1,0xBF,0xBD,0xBB,0xB9, 0xB7,0xB5,0xB3,0xB1,0xAE,0xAC,0xAA,0xA7, 0xA5,0xA3,0xA0,0x9E,0x9B,0x99,0x97,0x94, 0x92,0x8F,0x8D,0x8A,0x88,0x85,0x83,0x80, 0x7D,0x7B,0x78,0x76,0x73,0x71,0x6E,0x6C, 0x69,0x67,0x65,0x62,0x60,0x5D,0x5B,0x59, 0x56,0x54,0x52,0x4F,0x4D,0x4B,0x49,0x47, 0x45,0x43,0x41,0x3F,0x3D,0x3B,0x39,0x37, 0x35,0x34,0x32,0x30,0x2E,0x2D,0x2C,0x2A, 0x29,0x28,0x26,0x25,0x24,0x23,0x22,0x21, 0x20,0x1F,0x1E,0x1D,0x1D,0x1C,0x1C,0x1B, 0x1B,0x1A,0x1A,0x1A,0x19,0x19,0x19,0x19, 0x19,0x19,0x19,0x19,0x1A,0x1A,0x1A,0x1B, 0x1B,0x1C,0x1C,0x1D,0x1D,0x1E,0x1F,0x20, 0x21,0x22,0x23,0x24,0x25,0x26,0x28,0x29, 0x2A,0x2C,0x2D,0x2F,0x30,0x32,0x34,0x35, 0x37,0x39,0x3B,0x3D,0x3F,0x41,0x43,0x45, 0x47,0x49,0x4B,0x4D,0x4F,0x52,0x54,0x56, 0x59,0x5B,0x5D,0x60,0x62,0x65,0x67,0x69, 0x6C,0x6E,0x71,0x73,0x76,0x78,0x7B,0x7D }; unsigned code thr[256]={0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87, 0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F, 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97, 0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F, 0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7, 0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7, 0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF, 0xBF,0xBE,0xBD,0xBC,0xBB,0xBA,0xB9,0xB8, 0xB7,0xB6,0xB5,0xB4,0xB3,0xB2,0xB1,0xB0,0xAF,0xAE,0xAD,0xAC,0xAB,0xAA,0xA9,0xA8, 0xA7,0xA6,0xA5,0xA4,0xA3,0xA2,0xA1,0xA0, 0x9F,0x9E,0x9D,0x9C,0x9B,0x9A,0x99,0x98, 0x97,0x96,0x95,0x94,0x93,0x92,0x91,0x90, 0x8F,0x8E,0x8D,0x8C,0x8B,0x8A,0x89,0x88, 0x87,0x86,0x85,0x84,0x83,0x82,0x81,0x80, 0x7F,0x7E,0x7D,0x7C,0x7B,0x7A,0x79,0x78, 0x77,0x76,0x75,0x74,0x73,0x72,0x71,0x70, 0x6F,0x6E,0x6D,0x6C,0x6B,0x6A,0x69,0x68, 0x67,0x66,0x65,0x64,0x63,0x62,0x61,0x60, 0x5F,0x5E,0x5D,0x5C,0x5B,0x5A,0x59,0x58, 0x57,0x56,0x55,0x54,0x53,0x52,0x51,0x50, 0x4F,0x4E,0x4D,0x4C,0x4B,0x4A,0x49,0x48, 0x47,0x46,0x45,0x44,0x43,0x42,0x41,0x40, 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47, 0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F, 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57, 0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F, 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67, 0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F, 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77, 0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F }; unsigned code squ[256]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff};#endif
显示部分功能代码来源某站UP主，仿真结果
