|
1． 實(shí)驗(yàn)任務(wù) 用AT89S51單片機(jī)的P0.0/AD0－P0.7/AD7端口接數(shù)碼管的a－h端，8位數(shù)碼管的S1－S8通過74LS138譯碼器的Y0－Y7來控制選通每個(gè)數(shù)碼管的位選端。AT89S51單片機(jī)的P1.0－P1.2控制74LS138的A，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 
3． 系統(tǒng)板上硬件連線 （1． 把“單片機(jī)系統(tǒng)”區(qū)域中的P0.0/AD0－P0.7/AD7用8芯排線連接到“動(dòng)態(tài)數(shù)碼顯示”區(qū)域中的a－h端口上； （2． 把“三八譯碼模塊”區(qū)域中的Y0－Y7用8芯排線連接到“動(dòng)態(tài)數(shù)碼顯示”區(qū)域中的S1－S8端口上； （3． 把“單片機(jī)系統(tǒng)”區(qū)域中的P1.0－P1.2端口用3根導(dǎo)線連接到“三八譯碼模塊”區(qū)域中的A、B、C“端口上； 4． 程序設(shè)計(jì)方法 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1ms到4ms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。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;i<8;i++) { dispbuf[i]=16; } for(i=0;i<u;i++) { dispbuf[i]=8; } } }
|
66821730(技術(shù)支持)
