新聞中心

EEPW首頁(yè) > 嵌入式系統(tǒng) > 設(shè)計(jì)應(yīng)用 > 拉幕式數(shù)碼顯示技術(shù)

拉幕式數(shù)碼顯示技術(shù)

作者: 時(shí)間:2011-02-27 來源:網(wǎng)絡(luò) 收藏

1. 實(shí)驗(yàn)任務(wù)

AT89S51P0.0/AD0P0.7/AD7端口接數(shù)碼管的ah端,8位數(shù)碼管的S1S8通過74LS138譯碼器的Y0Y7來控制選通每個(gè)數(shù)碼管的位選端。AT89S51P1.0P1.2控制74LS138A,B,C端子。在8位數(shù)碼管上從右向左循環(huán)顯示“12345678”。能夠比較平滑地看到拉幕的效果。

2.電路原理圖

4.21.1

3.系統(tǒng)板上硬件連線

(1. 把“系統(tǒng)”區(qū)域中的P0.0/AD0P0.7/AD78芯排線連接到“動(dòng)態(tài)數(shù)碼顯示”區(qū)域中的ah端口上;

(2. 把“三八譯碼模塊”區(qū)域中的Y0Y78芯排線連接到“動(dòng)態(tài)數(shù)碼顯示”區(qū)域中的S1S8端口上;

(3. 把“單片機(jī)系統(tǒng)”區(qū)域中的P1.0P1.2端口用3根導(dǎo)線連接到“三八譯碼模塊”區(qū)域中的A、BC“端口上;

4.程序設(shè)計(jì)方法

(1. 動(dòng)態(tài)數(shù)碼顯示技術(shù);如何進(jìn)行動(dòng)態(tài)掃描,由于一次只能讓一個(gè)數(shù)碼管顯示,因此,要顯示8位的數(shù)據(jù),必須經(jīng)過讓數(shù)碼管一個(gè)一個(gè)輪流顯示才可以,同時(shí)每個(gè)數(shù)碼管顯示的時(shí)間大約在1ms4ms之間,所以為了保證正確顯示,我必須每隔1ms,就得刷新一個(gè)數(shù)碼管。而這刷新時(shí)間我們采用單片機(jī)的定時(shí)/計(jì)數(shù)器T0來控制,每定時(shí)1ms對(duì)數(shù)碼管刷新一次,T0采用方式2。

(2. 在進(jìn)行數(shù)碼顯示的時(shí)候,要對(duì)顯示單元開辟8個(gè)顯示緩沖區(qū),每個(gè)顯示緩沖區(qū)裝有顯示的不同數(shù)據(jù)即可。

5.程序框圖

主程序框圖


中斷服務(wù)程序

6.匯編源程序

DISPBUF EQU 30H

DISPCNT EQU 38H

DISPBIT EQU 39H

T1CNTA EQU 3AH

T1CNTB EQU 3BH

CNT EQU 3CH

ORG 00H

LJMP START

ORG 0BH

LJMP INT_T0

START: MOV DISPCNT,#8

MOV A,#10

MOV R1,#DISPBUF

LP: MOV @R1,A

INC R1

DJNZ DISPCNT,LP

MOV DISPBIT,#00H

MOV T1CNTA,#00H

MOV T1CNTB,#00H

MOV CNT,#00H

MOV TMOD,#01H

MOV TH0,#(65536-1000) / 256

MOV TL0,#(65536-1000) MOD 256

SETB TR0

SETB ET0

SETB EA

SJMP $

INT_T0:

MOV TH0,#(65536-1000) / 256

MOV TL0,#(65536-1000) MOD 256

MOV A,DISPBIT

ADD A,#DISPBUF

MOV R0,A

MOV A,@R0

MOV DPTR,#TABLE

MOVC A,@A+DPTR

MOV P0,A

MOV A,P1

ANL A,#0F8H

ADD A,DISPBIT

MOV P1,A

INC DISPBIT

MOV A,DISPBIT

CJNE A,#08H,NEXT

MOV DISPBIT,#00H

NEXT: INC T1CNTA

MOV A,T1CNTA

CJNE A,#50,LL1

MOV T1CNTA,#00H

INC T1CNTB

MOV A,T1CNTB

CJNE A,#8,LL1

MOV T1CNTB,#00H

INC CNT

MOV A,CNT

CJNE A,#9,LLX

MOV CNT,#00H

MOV A,CNT

LLX: CJNE A,#01H,NEX1

MOV 30H,#8

LL1: LJMP DONE

NEX1: CJNE A,#02H,NEX2

MOV 31H,#8

MOV 30H,#8

LJMP DONE

NEX2: CJNE A,#03H,NEX3

MOV 32H,#8

MOV 31H,#8

MOV 30H,#8

LJMP DONE

NEX3: CJNE A,#04H,NEX4

MOV 33H,#8

MOV 32H,#8

MOV 31H,#8

MOV 30H,#8

LJMP DONE

NEX4: CJNE A,#05H,NEX5

MOV 34H,#8

MOV 33H,#8

MOV 32H,#8

MOV 31H,#8

MOV 30H,#8

LJMP DONE

NEX5: CJNE A,#06H,NEX6

MOV 35H,#8

MOV 34H,#8

MOV 33H,#8

MOV 32H,#8

MOV 31H,#8

MOV 30H,#8

LJMP DONE

NEX6: CJNE A,#07H,NEX7

MOV 36H,#8

MOV 35H,#8

MOV 34H,#8

MOV 33H,#8

MOV 32H,#8

MOV 31H,#8

MOV 30H,#8

LJMP DONE

NEX7: CJNE A,#08H,NEX8

MOV 37H,#8

MOV 36H,#8

MOV 35H,#8

MOV 34H,#8

MOV 33H,#8

MOV 32H,#8

MOV 31H,#8

MOV 30H,#8

LJMP DONE

NEX8: CJNE A,#00H,DONE

MOV 37H,#10

MOV 36H,#10

MOV 35H,#10

MOV 34H,#10

MOV 33H,#10

MOV 32H,#10

MOV 31H,#10

MOV 30H,#10

LL: LJMP DONE

DONE: RETI

TABLE: DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH,00H

END

7.C語(yǔ)言源程序

#include AT89X51.H>

unsigned char code dispcode[]={0x3f,0x06,0x5b,0x4f,

0x66,0x6d,0x7d,0x07,

0x7f,0x6f,0x77,0x7c,

0x39,0x5e,0x79,0x71,0x00};

unsigned char dispbitcode[]={0xf8,0xf9,0xfa,0xfb,

0xfc,0xfd,0xfe,0xff};

unsigned char dispbuf[8]={16,16,16,16,16,16,16,16};

unsigned char dispbitcnt;

unsigned int t02scnt;

unsigned char t5mscnt;

unsigned char u;

unsigned char i;

void main(void)

{

TMOD=0x02;

TH0=0x06;

TL0=0x06;

TR0=1;

ET0=1;

EA=1;

while(1);

}

void t0(void) interrupt 1 using 0

{

t5mscnt++;

if(t5mscnt==4)

{

t5mscnt=0;

P0=dispcode[dispbuf[dispbitcnt]];

P1=dispbitcode[dispbitcnt];

dispbitcnt++;

if(dispbitcnt==8)

{

dispbitcnt=0;

}

}

t02scnt++;

if(t02scnt==1600)

{

t02scnt=0;

u++;

if(u==9)

{

u=0;

}

for(i=0;i8;i++)

{

dispbuf[i]=16;

}

for(i=0;iu;i++)

{

dispbuf[i]=8;

}

}

}



評(píng)論


相關(guān)推薦

技術(shù)專區(qū)

關(guān)閉