信号发生器设计报告

信号发生器设计报告—基于STC89C52单片机的信号发生器张蓉（测仪101，5801210038）设计方案：采用AT89C51单片机和DAC0832数模转换器生成波形，加上一个低通滤波器，生成的波形比较纯净。它的特点是可产生任意波形，频率容易调节，频率能达到设计的500HZ以上。性能高，在低频范围内稳定性好、操作方便、体积小、耗电少。将输出电压通过一个运算放大器的放大。这样还有个优点是幅度连续可调。工作原理：数字信号可以通过数/模转换器转换成模拟信号，因此可通过产生数字信号再转换成模拟信号的方法来获得所需要的波形。89C51单片机本身就是一个完整的微型计算机，具有组成微型计算机的各部分部件：中央处理器CPU、随机存取存储器RAM、只读存储器ROM、I/O接口电路、定时器/计数器以及串行通讯接口等，只要将89C51再配置键盘及、数模转换及波形输出、放大电路等部分，即可构成所需的波形发生器。各部分电路图：单片机最小系统：数/模转换电路：运放电路:总电路图：主流程图：实物图：调试过程:调试过程：不通电，用万用表根据电路图仔细检查各线路连接是否正常。首先是调试单片机部分，DA和运算放大器芯片不接。用STC_ISP_V483软件通过串口下程序。看是否可以正常下程序。当可以正常下程序时，给51单片机下一个让所有I/0口一会儿输入0，延时，再输出1，以此类推。用万用表测量各I/O口得电压是不是一会儿高，一会儿低。安上DA和运算放大器芯片，给单片机下一个输出正弦波的测试程序，通过示波器看输出是否正常。给单片机下一个完整的程序，分别按下S1，看波形是否改变。按下S2，看频率是否改变。系统仿真波形：矩形波：锯齿波：三角波：程序：#include<reg51.h>#defineucharunsignedchar#defineuintunsignedintsbitcsda=P2^2;sbitwr=P2^1;sbits1=P3^2;sbits2=P3^3;uchark=0,p=0,delay=0;ucharbxxz=0;pinglv=0;uchara=1,b=0,c=0,d=0,e=0;ucharcodesin[64]={135,145,158,167,176,188,199,209,218,226,234,240,245,249,252,254,254,253,251,247,243,237,230,222,213,204,193,182,170,158,146,133,121,108,96,84,72,61,50,41,32,24,17,11,7,3,1,0,0,2,5,9,14,20,28,36,45,55,66,78,90,102,114,128};ucharcodejuxing[64]={255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};ucharcodejuchi[64]={0,4,8,12,16,20,24,28,32,36,40,45,49,53,57,61,65,69,73,77,81,85,89,93,97,101,105,109,113,117,121,125,130,134,138,142,146,150,154,158,162,166,170,174,178,182,186,190,194,198,202,206,210,215,219,223,227,231,235,239,243,247,251,255};ucharcodetixing[64]={0,13,26,39,52,65,78,91,104,117,130,143,156,169,182,195,208,221,234,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,247,242,229,216,203,190,177,164,151,138,125,112,99,86,73,60,47,34,21,8};ucharcodesanjiao[64]={0,8,16,24,32,40,48,56,64,72,80,88,96,104,112,120,128,136,144,152,160,168,176,184,192,200,208,216,224,232,240,248,248,240,232,224,216,208,200,192,184,176,168,160,152,144,136,128,120,112,104,96,88,80,72,64,56,48,40,32,24,16,8,0};voiddelay1(){ inta,b; for(a=1;a>0;a--) for(b=122;b>0;b--);}voidint0()interrupt0{ EX0=0; delay1(); if(s1==0){ bxxz++; if(bxxz==5) bxxz=0; switch(bxxz) { case0: {a=1,b=0,c=0,d=0,e=0;} break; case1: {a=0,b=1,c=0,d=0,e=0;} break; case2: {a=1,b=0,c=1,d=0,e=0;} break; case3: {a=0,b=0,c=0,d=1,e=0;} break; case4: {a=0,b=0,c=0,d=0,e=1;} break; } delay1(); while(!s1); } while(!s1); EX0=1;}voidint1()interrupt2{ EX1=0; delay1(); if(s2==0){ p++; if(p==8) p=0; switch(p) { case1: pinglv=3; break; case2: pinglv=6; break; case3: pinglv=9; break; case4: pinglv=12; break; case5: pinglv=15; break; case6: pinglv=18; break; case7: pinglv=21; break; default: pinglv=0; break; } delay1(); while(!s2); } while(!s2); EX1=1;}voidmain(){ csda=0; wr=0; EA=1; IT0=1; EX0=1; IT1=1; EX1=1; while(1) { while(a) { delay=pinglv; P0=sin[k]; k++; if(k==64) k=0; while(delay) delay--; } while(b) { delay=pinglv; P0=juxing[k]; k++; if(k==64) k=0; while(delay) delay--; } while(c) { delay=pinglv; P0=juchi[k]; k++; if(k==64) k=0; while(delay) delay--; } while(d) { delay=pinglv; P0=tixing[k]; k++