使用51单片机制作函数信号发生器(DAC0832仿真演示)

文章目录

  • (1)DA转换
  • (2)DAC0832简介
  • (3)电路设计
  • (4)参考例程
  • (5)参考文献
  • (1)DA转换

    单片机作为一个数字电路系统,当需要采集外界模拟量的使用需要进行AD转换,将模拟量转换成数字量,供单片机使用。51单片机需要外部配置一个AD转换芯片来进行模拟量的采集,如我之前写了一篇ADC0832的使用。高级的单片机如STC12和STM32已经集成了AD转换功能,只需简单配置一下,便可以采集到AD转换后的数据。

    AD转换(Analog to Digital)是模拟量转换数字量,那么DA转换(Digital to Analog)便是数字量转换成模拟量。

    使用DAC0832进行数字到模拟的转换,再使用定时器控制输出波形的频率便可以制作一个函数信号发生器。

    (2)DAC0832简介





    CS:低电平有效,片选输入线
    WR1:低电平大于500ms有效,输入锁存器
    WR2:高电平有效,与XFER结合可将输入锁存器的8位数据传输到DAC寄存器中
    XFER:低电平有效,数据传输控制输入线
    DI0~DI7:8位数据位并行输入,有效时间大于90ns有效
    VCC:电源输入5V-15V
    VERF:基准电压输入线-10V~10V
    RFB:反馈信号输入,可以看成一个反馈监测
    IOUT1:电流输出1,其值随着输入线性变化
    IOUT2:电流输出2,与OUT1值之和为一个常数

    (3)电路设计

    单片机最小系统

    波形切换控制

    (这里由于博主时间有限,例程代码的LED显示功能就没有写了)



    (4)参考例程

    #include <reg52.h>
    #define uchar unsigned char
    #define uint unsigned int
    
    #define DI	P0											//8位数据输入线
    
    //sbit sine_wave_LED1					= P1^0;	//正弦波指示灯
    //sbit square_wave_LED2 			= P1^1;	//方波指示灯
    //sbit triangular_wave_LED3 	= P1^2;	//三角波指示灯
    //sbit sawtooth_wave_LED4			= P1^3;	//锯齿波指示灯
    sbit change_wave_Key				= P1^4;	//更换波形
    
    uint freq = 3906;										//定时数值×16^(-6)×256 = 波形频率 例程使用1KHZ
    uint number=1,n=0,THHL,i;
    
    //正弦波段码
    unsigned 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   
                                                                       };   
    //三角波段码
    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    
                                                                       }; 
    
    //方波段码																																	 
    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												
    														};
    															
    
    //10ms延时函数
    void delay_10ms(uchar i)
    {
    	//毫秒级延时函数
    	//在12MHZ下晶振下,大约延时10ms/次
        uchar a,b,c;
    		for(c = i; c > 0; --c)
    	    for(b = 129; b > 0; b--)
    				for(a = 38; a > 0; a--);
    }
    
    //定时器0初始化
    void Timer0Init(void)
    {
    	unsigned int THHL;
    	TMOD &= 0xF0;				//定时器1失效
    	TMOD |= 0x01;				//定时器0,16位计数
    	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;							//开定时器0中断
    	EA=1;								//开总中断
    	PT0=0;							//定时器0中断最优
    }
    
    void main()
    {
    	/*指示灯初始化,全部熄灭*/
    //	triangular_wave_LED3  = 1;
    //	square_wave_LED2			= 1;
    //	sine_wave_LED1				= 1;
    	
    	Timer0Init();//初始化定时器0
    	
    	while(1)
    	{
    		if(change_wave_Key == 0)
    		{
    			delay_10ms(1);//延时消抖
    			if(change_wave_Key == 0)
    			{
    				while(!change_wave_Key);//松手检测
    				number++;
    				
    				if(number == 5)
    				{
    					number = 0;
    				}
    			}
    		}
    		
    		switch(number)
    		{
    			case 1:	{DI=sin[n]; break;}//正弦波
    			case 2: {DI=thr[n]; break;}//三角波
    			case 3: {for(i=0;i<256;i++){DI=squ[i];} break;}//方波
    			case 4:	{DI=256-n; break;}//锯齿波
    			default:{break;}
    		}
    		
    	}
    }
    
    //定时器0中断处理函数
    void Timer0_Routine() interrupt 1
    {
    	THHL=65536-freq;
    	TL0=THHL%256;
    	TH0=THHL/256;  
    	if(n>=255) 
    	{n=0;} 
    	else 
    	{n++;}   
    }
    
    

    电路仿真及代码例程
    链接:https://share.weiyun.com/ALLrnKTu 密码:cchvph

    (5)参考文献

    基于51单片机的DAC0832波形发生器

    由于作者水平有限,如有错误望指摘。

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