1、 姓名： 学号： 实 验 报 告实验项目名称： D/A、A/D转换实验 同组人： 实验时间： 实验室： 指导教师： 一、实验目的：（l）学习外部接口的应用。ADC0809、DAC0832的工作方式，输入/输出方式的应用。（2）熟悉Proteus软件电路设计和Keil软件程序调试方法。重点：ADC0809、DAC0832的工作方式二、实验顶备知识： （l）AT89S51与ADC、DAC接口的连接，ADC0809、DAC0832的基本原理。（2）Proteus软件应用，Keil软件程序调试应用。三、实验内容 利用DAC0832转换器输出锯齿波、三角波、方波和正弦波。1、设计要求：以DAC0832转
2、换器和AT89C52单片机设计仿真电路，该电路能在虚拟示波器上显示出锯齿波、三角波、方波和正弦波，并能用虚拟电压表显示输出电压值，要求电压范围为015V且周期约为510ms。2、仿真电路原理图元器件选取：AT89C52：单片机；RES、RX8：电阻、8排阻；CRYSTAL：晶振；CAP、CAP-ELEC：电容、电解电容；DAC0832：D/A转换器；LM358N：运算放大器。图6-1 电路原理图3、程序设计内容程序设计首先考虑DAC0832转换芯片的入口地址，地址的设置与接口电路的连接方式有关。P2.7端口与DAC0832的CS片选端相连，要选通DAC0832，要求CS引脚为低电平，则DAC0
3、832的入口地址为0x7FFFH。4、程序清单 #include #include #include #define DAC0832Addr1 0x7FFF #define DAC0832Addr2 0xBFFF#define DAC0832Addr3 0xDFFF#define DAC0832Addr4 0xEFFF#define uchar unsigned char#define uint unsigned intuchar p; float f;int a; #define pi 3.1415926 void Uart_Init( void ); void TransformData1
4、(uchar c0832data1);void TransformData2(uchar c0832data2);void TransformData3(uchar c0832data3);void TransformData4 (uchar c0832data4);void Delay();uchar const code ZXB_code255=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
5、,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
6、,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
7、,0x4c,0x49,0x46,0x43,0x41,0x3e,0x3b,0x39,0x36,0x33,0x31,0x2e,0x2c,0x2a,0x27,0x25,0x23,0x21,0x1f,0x1d,0x1b,0x19,0x17,0x15,0x14,0x12,0x10,0xf,0xd,0xc,0xb,0x9,0x8,0x7,0x6,0x5,0x4,0x3,0x3,0x2,0x1,0x1,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x1,0x1,0x2,0x3,0x3,0x4,0x5,0x6,0x7,0x8,0x9,0xa,0xc,0xd,0xe,
8、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;main() uchar cDigital1=0; Uart_Init();P0=0xFF;P1=0xFF;P2=0xFF;P3=0xFF;Delay();while(1)for(
9、cDigital1=0;cDigital10;cDigital1-) Delay(); TransformData1(cDigital1);TransformData2(cDigital1);TransformData3(255);TransformData4(ZXB_code-(cDigital1-255); void TransformData1(uchar c0832data1) *(uchar xdata*)DAC0832Addr1)=c0832data1; void TransformData2(uchar c0832data2) *(uchar xdata*)DAC0832Addr
10、2)=c0832data2; void TransformData3(uchar c0832data3) *(uchar xdata*)DAC0832Addr3)=c0832data3; void TransformData4(uchar c0832data4) *(uchar xdata*)DAC0832Addr4)=c0832data4; void Uart_Init( void )SCON=0x52;TMOD=0x21;TCON=0x69;TH1=0xf3;void Delay()uint i; for (i=0;i250;i+) ; ADC0809电压模/数转换1、设计要求：以AT89
11、C52单片机为核心设计ADC0809模数转换仿真电路，模拟电压输入由可变电位器提供。输入电压范围04.99V，经ADC0809转换成对应的0255通过数码管显示。2、仿真电路原理图元器件选取： AT89C52：单片机；RES：电阻；CRYSTAL：12MHz晶振；CAP、CAP-ELEC：电容、电解电容；7SEG-MPX4-CC：4位七段共阴极数码管；74LS02、74LS04、74LS74、74LS373或非门、反相位、D触发器、地址锁存器；POT-LIN：变阻器；ADC0809：8位A/D转换器。图6-2 电路原理图3、程序设计内容将单片机的P0.0、P0.1和P0.2通过74LS373地
12、址锁存器与ADC0809的ADDA、ADDB和ADDC相连接，选择ADC0809的采集通道IN0。P2.7控制ADC0809的ALE和OE端口，因此ADC0809的地址可以定位ox7FF8。4、程序清单 #include #include #define unit unsigned int#define uchar unsigned char#define AD XBYTE 0x7FF8sbit led1=P20;sbit led2=P21;sbit led3=P22;sbit led4=P23;sbit ad_busy=P32;bit bk=1;unsigned char ad_data,
13、LED1, LED2, LED3;ucharcode led_segment12=0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x00,0x00; void delay(unsigned int i)while( i )i-;void display(void) LED1=ad_data%10;LED2=(ad_data/10)%10;LED3=ad_data/100;P2=0xff;delay(2);P1=led_segmentLED1; led1=0;delay(100);led1=1;if(LED3=0)&(LED2=0) LED2
14、=10;P1=led_segmentLED2;led2=0;delay(100);led2=1;if(LED3=0) LED3=10;P1=led_segmentLED3;led3=0;delay(100);led3=1;bk=!bk;void ad0808(void) interrupt 0 EA=0;EX0=0;ad_data=AD;EA=1;EX0=1;void main(void)EA=1; EX0=1; ad_data=0;ad_busy=0;while(1)if( bk )AD=0;display();四、实验结果及分析：1、 DAC0832转换器输出锯齿波、三角波、方波和正弦波2、ADC0809电压模/数转换五、思考题：1、DAC转换器的主要性能指标有哪些？目前常用的DAC转换器主要有哪几种类型？各有什么特点？2、ADC转换器的主要性能指标有哪些？目前常用的ADC转换器主要有哪几种类型？各有什么特点？指导教师批阅及成绩 年 月 日- 8 -
