課程設(shè)計(jì)（論文）基于51單片機(jī)函數(shù)信號(hào)發(fā)生器設(shè)計(jì)

1、摘 要: 本系統(tǒng)利用單片機(jī)stc89c52采用程序設(shè)計(jì)方法產(chǎn)生鋸齒波、正弦波、矩形波三種波形，再通過(guò)d/a轉(zhuǎn)換器dac0832將數(shù)字信號(hào)轉(zhuǎn)換成模擬信號(hào)，濾波放大，最終由示波器顯示出來(lái)，能產(chǎn)1001khz的波形。，并通過(guò)液晶屏1602顯示其各自的類(lèi)型以及數(shù)值，系統(tǒng)大致包括信號(hào)發(fā)生部分、數(shù)/模轉(zhuǎn)換部分以及液晶顯示部分三部分，其中尤其對(duì)數(shù)/模轉(zhuǎn)換部分和波形產(chǎn)生和變化部分進(jìn)行詳細(xì)論述。關(guān)鍵詞：?jiǎn)纹瑱C(jī)stc89c52、dac0832、液晶1602abstract: this system capitalize on stc89c52，it makes use of central processor t

2、o generate three kinds of waves, they are triangle wave, and use d/a conversion module, wave generate module and liquid crystal display of 1602, it can have the 100hz-1000hz profile. in this system it can control wave form choosing, frequency, range,can have the sine wave, the square-wave, the trian

3、gular wave. simultaneously may also take the frequency measurement frequency,and displays them through liquid crystal display of 1602. this design includes three modules. they are d/a conversion module, wave generate module and liquid crystal display of led module. in this design, the wave generator

4、 into wave form module and d/a conversion module are discussed in detail. key word: stc89c52, dac0832, liquid crystal 1602.目錄1. 系統(tǒng)設(shè)計(jì)1.1 設(shè)計(jì)要求 1.2方案設(shè)計(jì)與論證 1.2.1 信號(hào)發(fā)生電路方案論證 1.2.2 單片機(jī)的選擇論證 1.2.3 顯示方案論證 1.2.4 鍵盤(pán)方案論證 1.3 總體系統(tǒng)設(shè)計(jì) 1.4 硬件實(shí)現(xiàn)及單元電路設(shè)計(jì) 1.4.1 單片機(jī)最小系統(tǒng)的設(shè)計(jì)1.4.2 波形產(chǎn)生模塊設(shè)計(jì) 1.4.3 顯示模塊的設(shè)計(jì) 1.4.4 鍵盤(pán)模塊的設(shè)計(jì)1.5 軟

5、件設(shè)計(jì)流程 1.6 源程序2. 輸出波形的種類(lèi)與頻率的測(cè)試2.1 測(cè)試儀器及測(cè)試說(shuō)明2.2 測(cè)試結(jié)果3. 設(shè)計(jì)心的及體會(huì)4. 附錄 4.1 參考文獻(xiàn) 1、 系統(tǒng)設(shè)計(jì) 經(jīng)過(guò)考慮，我們確定方案如下：利用at89s52單片機(jī)采用程序設(shè)計(jì)方法產(chǎn)生鋸齒波、正弦波、矩形波三種波形，再通過(guò)d/a轉(zhuǎn)換器dac0832將數(shù)字信號(hào)轉(zhuǎn)換成模擬信號(hào)，濾波放大，最終由示波器顯示出來(lái)，通過(guò)鍵盤(pán)來(lái)控制三種波形的類(lèi)型選擇、頻率變化，最終輸出顯示其各自的類(lèi)型以及數(shù)值。1.1、設(shè)計(jì)要求 1)、利用單片機(jī)采用軟件設(shè)計(jì)方法產(chǎn)生三種波形 2）、三種波形可通過(guò)鍵盤(pán)選擇 3）、波形頻率可調(diào) 4）、需顯示波形的種類(lèi)及其平率1.2方案設(shè)計(jì)與論

6、證 1.2.1 信號(hào)發(fā)生電路方案論證 方案一：通過(guò)單片機(jī)控制d/a，輸出波形。此方案輸出的波形不夠穩(wěn)定，抗干擾能力弱，不易調(diào)節(jié)。但此方案電路簡(jiǎn)單、成本低。 方案二：使用傳統(tǒng)的鎖相頻率合成方法。通過(guò)芯片ic145152，壓控振蕩器搭接的鎖相環(huán)電路輸出穩(wěn)定性極好的正弦波，再利用過(guò)零比較器轉(zhuǎn)換成方波，積分電路轉(zhuǎn)換成三角波。此方案，電路復(fù)雜，干擾因素多，不易實(shí)現(xiàn)。 方案三：利用max038芯片組成的電路輸出波形。max038是精密高頻波形產(chǎn)生電路，能夠產(chǎn)生準(zhǔn)確的三角波、方波和正弦波三種周期性波形。但此方案成本高，程序復(fù)雜度高。以上三種方案綜合考慮，選擇方案一。1.2.2 單片機(jī)的選擇論證 方案一：st

7、c89s52單片機(jī)是一種高性能8位單片微型計(jì)算機(jī)。它把構(gòu)成計(jì)算機(jī)的中央處理器cpu、存儲(chǔ)器、寄存器、i/o接口制作在一塊集成電路芯片中，從而構(gòu)成較為完整的計(jì)算機(jī)、而且其價(jià)格便宜。方案二：c8051f005單片機(jī)是完全集成的混合信號(hào)系統(tǒng)級(jí)芯片，具有與8051兼容的微控制器內(nèi)核，與mcs-51指令集完全兼容。除了具有標(biāo)準(zhǔn)8052的數(shù)字外設(shè)部件，片內(nèi)還集成了數(shù)據(jù)采集和控制系統(tǒng)中常用的模擬部件和其他數(shù)字外設(shè)及功能部件，而且執(zhí)行速度快。但其價(jià)格較貴以上兩種方案綜合考慮，選擇方案一 1.2.3 顯示方案論證 方案一：采用led數(shù)碼管。led數(shù)碼管由8個(gè)發(fā)光二極管組成，每只數(shù)碼管輪流顯示各自的字符。由于人眼

8、具有視覺(jué)暫留特性，當(dāng)每只數(shù)碼管顯示的時(shí)間間隔小于1/16s時(shí)人眼感覺(jué)不到閃動(dòng)，看到的是每只數(shù)碼管常亮。使用數(shù)碼管顯示編程較易，但要顯示內(nèi)容多，而且數(shù)碼管不能顯示字母。 方案二：采用lcd液晶顯示器1602。其功率小，效果明顯，顯示編程容易控制，可以顯示字母。以上兩種方案綜合考慮，選擇方案二。1.2.4 鍵盤(pán)方案論證方案一：獨(dú)立鍵盤(pán)。獨(dú)立鍵盤(pán)的按鍵觸點(diǎn)一端接于單片機(jī)，另一端接于地。當(dāng)鍵盤(pán)上沒(méi)有鍵閉合時(shí)，單片機(jī)引腳為高電平。當(dāng)某一個(gè)鍵閉合時(shí)，該鍵所對(duì)應(yīng)的單片機(jī)引腳為低電平。方案二：編碼式鍵盤(pán)。編碼式鍵盤(pán)的按鍵觸點(diǎn)接于74ls148芯片。當(dāng)鍵盤(pán)上沒(méi)有閉合時(shí)，所有鍵都斷開(kāi)，當(dāng)某一鍵閉合時(shí)，該鍵對(duì)應(yīng)的編

9、碼由74ls148輸出。以上兩種方案綜合考慮，選擇方案一。1.3總體系統(tǒng)設(shè)計(jì)該系統(tǒng)采用單片機(jī)作為數(shù)據(jù)處理及控制核心，由單片機(jī)完成人機(jī)界面、系統(tǒng)控制、信號(hào)的采集分析以及信號(hào)的處理和變換，采用按鍵輸入，利用液晶顯示電路輸出數(shù)字顯示的方案。將設(shè)計(jì)任務(wù)分解為按鍵電路、液晶顯示電路等模塊。圖（1）為系統(tǒng)的總體框圖 圖（1） 總體方框圖1.4硬件實(shí)現(xiàn)及單元電路設(shè)計(jì) 1.4.1單片機(jī)最小系統(tǒng)的設(shè)計(jì)89c51是片內(nèi)有rom/eprom的單片機(jī)，因此，這種芯片構(gòu)成的最小系統(tǒng)簡(jiǎn)單可靠。用80c51單片機(jī)構(gòu)成最小應(yīng)用系統(tǒng)時(shí)，只要將單片機(jī)接上時(shí)鐘電路和復(fù)位電路即可，如圖（2） 89c51單片機(jī)最小系統(tǒng)所示。由于集成度

10、的限制，最小應(yīng)用系統(tǒng)只能用作一些小型的控制單元。其應(yīng)用特點(diǎn)：(1) 有可供用戶使用的大量i/o口線。(2) 內(nèi)部存儲(chǔ)器容量有限。(3) 應(yīng)用系統(tǒng)開(kāi)發(fā)具有特殊性。圖（2） 89c51單片機(jī)最小系統(tǒng)1.4.2 波形產(chǎn)生模塊設(shè)計(jì) 由單片機(jī)采用編程方法產(chǎn)生三種波形、通過(guò)da轉(zhuǎn)換模塊dac0832在進(jìn)過(guò)濾波放大之后輸出。其電路圖如下： 圖（3）波形產(chǎn)生電路如上圖所示，單片機(jī)的p0口連接dac0832的八位數(shù)據(jù)輸入端，dac0832的輸出端接放大器，經(jīng)過(guò)放大后輸出所要的波形。dac0832的為八位數(shù)據(jù)并行輸入的，其結(jié)構(gòu)圖如下： 圖（4）dac0832的內(nèi)部結(jié)構(gòu)1.4.3 顯示模塊的設(shè)計(jì)通過(guò)液晶1602顯示

11、輸出的波形、頻率，其電路圖如下： 圖（5）液晶顯示如上圖所示，1602的八位數(shù)據(jù)端接單片機(jī)的p1口，其三個(gè)使能端rs、rw、e分別接單片機(jī)的p3.2p3.4。通過(guò)軟件控制液晶屏可以顯示波形的種類(lèi)以及波形的頻率。1.4.4 鍵盤(pán)顯示模塊的設(shè)計(jì)本系統(tǒng)采用獨(dú)立鍵盤(pán)，其連接電路圖如下： 圖（6）鍵盤(pán)圖中鍵盤(pán)引出的三跟線分別接單片機(jī)的p2口。如圖開(kāi)關(guān)1用來(lái)切換輸出波形、開(kāi)關(guān)2和3用來(lái)調(diào)節(jié)頻率的加減。當(dāng)按開(kāi)關(guān)2時(shí)輸出波形的頻率增加，按開(kāi)關(guān)3時(shí)輸出波形的頻率減小。1.5 軟件設(shè)計(jì)流程本系統(tǒng)采用stc89c52單片機(jī)，用編程的方法來(lái)產(chǎn)生三種波形，并通過(guò)編程來(lái)切換三種波形以及波形頻率的改變。具體功能有：（1）各

12、個(gè)波形的切換；（2）各種參數(shù)的設(shè)定；（3）頻率增減等。軟件調(diào)通后，通過(guò)編程器下載到stc89c52芯片中，然后插到系統(tǒng)中即可獨(dú)立完成所有的控制。軟件的流程圖如下： 圖（7）程序流程圖1.6源程序#include#define uchar unsigned char #define uint unsigned int sbit cs=p20;sbit wr=p21;sbit lcden=p30;sbit lcdrs=p31;uchar num,fre;uchar code table1=wave:;uchar code table2=f:;uchar code tosin256=0x80,0x8

13、3,0x86,0x89,0x8d,0x90,0x93,0x96,0x99,0x9c,0x9f,0xa2,0xa5,0xa8,0xab,0xae,0xb1,0xb4,0xb7,0xba,0xbc,0xbf,0xc2,0xc5,0xc7,0xca,0xcc,0xcf,0xd1,0xd4,0xd6,0xd8,0xda,0xdd,0xdf,0xe1,0xe3,0xe5,0xe7,0xe9,0xea,0xec,0xee,0xef,0xf1,0xf2,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfd,0xfe,0xff,0xff,0xff,0xf

14、f,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xfe,0xfd,0xfd,0xfc,0xfb,0xfa,0xf9,0xf8,0xf7,0xf6,0xf5,0xf4,0xf2,0xf1,0xef,0xee,0xec,0xea,0xe9,0xe7,0xe5,0xe3,0xe1,0xde,0xdd,0xda,0xd8,0xd6,0xd4,0xd1,0xcf,0xcc,0xca,0xc7,0xc5,0xc2,0xbf,0xbc,0xba,0xb7,0xb4,0xb1,0xae,0xab,0xa8,0xa5,0xa2,0x9f,0x9c,0x99,0x96,0x9

15、3,0x90,0x8d,0x89,0x86,0x83,0x80,0x80,0x7c,0x79,0x76,0x72,0x6f,0x6c,0x69,0x66,0x63,0x60,0x5d,0x5a,0x57,0x55,0x51,0x4e,0x4c,0x48,0x45,0x43,0x40,0x3d,0x3a,0x38,0x35,0x33,0x30,0x2e,0x2b,0x29,0x27,0x25,0x22,0x20,0x1e,0x1c,0x1a,0x18,0x16,0x15,0x13,0x11,0x10,0x0e,0x0d,0x0b,0x0a,0x09,0x08,0x07,0x06,0x05,0x0

16、4,0x03,0x02,0x02,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x02,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0d,0x0e,0x10,0x11,0x13,0x15,0x16,0x18,0x1a,0x1c,0x1e,0x20,0x22,0x25,0x27,0x29,0x2b,0x2e,0x30,0x33,0x35,0x38,0x3a,0x3d,0x40,0x43,0x45,0x48,0x4c,0x4e,0x51,0x5

17、5,0x57,0x5a,0x5d,0x60,0x63,0x66,0x69,0x6c,0x6f,0x72,0x76,0x79,0x7c,0x80 ;/*正弦波碼 */uchar code tosqu256=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,0xf

18、f,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,07xff,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,0x

19、ff,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,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x

20、00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x

21、00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00; /*方波碼*/uchar code totri256=0x01,0x03,0x05,0x07,0x09,0x0b,0x0d,0x0f,0x11,0x13,0x15,0x17,0x19,0x1b,0x1d,0x1f,0x21,0x23

22、,0x25,0x27,0x29,0x2b,0x2d,0x2f,0x31,0x33,0x35,0x37,0x39,0x3b,0x3d,0x3f,0x41,0x43,0x45,0x47,0x49,0x4b,0x4d,0x4f,0x51,0x53,0x55,0x57,0x59,0x5b,0x5d,0x5f,0x61,0x63,0x65,0x67,0x69,0x6b,0x6d,0x6f,0x71,0x73,0x75,0x77,0x79,0x7b,0x7d,0x7f,0x81,0x83,0x85,0x87,0x89,0x8b,0x8d,0x8f,0x91,0x93,0x95,0x97,0x99,0x9b

23、,0x9d,0x9f,0xa1,0xa3,0xa5,0xa7,0xa9,0xab,0xad,0xaf,0xb1,0xb3,0xb5,0xb7,0xb9,0xbb,0xbd,0xbf,0xc1,0xc3,0xc5,0xc7,0xc9,0xcb,0xcd,0xcf,0xd1,0xd3,0xd5,0xd7,0xd9,0xdb,0xdd,0xdf,0xe1,0xe3,0xe5,0xe7,0x49,0xeb,0xed,0xef,0xf1,0xf3,0xf5,0xf7,0xf9,0xfb,0xfd,0xff,0xff,0xfd,0xfb,0xf9,0xf7,0xf5,0xf3,0xf1,0xef,0xed

24、,0xeb,0xe9,0xe7,0xe5,0xe3,0xe1,0xdf,0xdd,0xdb,0xd9,0xd7,0xd5,0xd3,0xd1,0xcf,0xcd,0xcb,0xc9,0xc7,0xc5,0xc3,0xc1,0xbf,0xbd,0xbb,0xb9,0xb7,0xb5,0xb3,0xb1,0xaf,0xad,0xab,0xa9,0xa7,0xa5,0xa3,0xa1,0x9f,0x9d,0x9b,0x99,0x97,0x95,0x93,0x91,0x8f,0x8d,0x8b,0x89,0x87,0x85,0x83,0x81,0x7f,0x7d,0x7b,0x79,0x77,0x75

25、,0x73,0x71,0x6f,0x6d,0x6b,0x69,0x67,0x65,0x63,0x61,0x5f,0x5d,0x5b,0x59,0x57,0x55,0x53,0x51,0x4f,0x4d,0x4b,0x49,0x47,0x45,0x43,0x41,0x3f,0x3d,0x3b,0x39,0x37,0x35,0x33,0x31,0x2f,0x2d,0x2b,0x29,0x27,0x25,0x23,0x21,0x1f,0x1d,0x1b,0x19,0x17,0x15,0x13,0x11,0x0f,0x0d,0x0b,0x09,0x07,0x05,0x03,0x01,;void del

26、ay(uint z)/延時(shí)子程序 uchar i,j; for(i=z;i0;i-) for(j=110;j0;j-);void delay1(uint y) /延時(shí)y 個(gè)機(jī)器周期 uint x; for(x=y;x0;x-); void write_com(uint com)/向液晶寫(xiě)命令 lcdrs=0; p1=com; delay(5); lcden=1; delay(5); lcden=0; void write_dat(uint dat) /向液晶寫(xiě)數(shù)據(jù) lcdrs=1; p1=dat; delay(5); lcden=1; delay(5); lcden=0; void write

27、_fre(uint fre)/向液晶寫(xiě)數(shù)據(jù)：需顯示的頻率 uchar qian,bai,shi,ge; qian=fre/1000; bai=fre/100%10; shi=fre/10%10; ge=fre%10; write_com(0x80+0x42); write_dat(qian); write_dat(bai); write_dat(shi); write_dat(ge); write_dat(0x48);/寫(xiě)hz，用ascii碼表示 write_dat(0x5a); void init_yej() /液晶初始化 lcden=0; write_com(0x38); write_co

28、m(0x0c); write_com(0x06); write_com(0x01); write_com(0x80+0x00);for(num=0;num5;num+) write_dat(table1num); /寫(xiě)wave: write_com(0x80+0x40); /寫(xiě) f： for(num=0;num1)t-;if(key3=0)t+; void daxianshi()/da+xianshi if(type=0) write_com(0x80+0x05); write_dat(s); /寫(xiě)sine: write_dat(i); write_dat(n);write_dat(e);wh

29、ile(1)p0=tosincount;count+;delay1(t);fre=(1000/(9+3*t); write_fre(fre);if(type=1)/squ write_com(0x80+0x05); /squre write_dat(s); write_dat(q); write_dat(u); write_dat(r); write_dat(e); while(1)p0=tosqucount;count+;delay1(t);fre=(100000/(3*t); write_fre(fre);if(type=2)/tri write_com(0x80+0x05); write_dat(t); /寫(xiě)trian: write_dat(r); write_dat(i); write_dat(a); write_dat(n); while