adc0809 basic.asm

ADC0808的数字电压表原理图

LED_0	EQU 	30H		 	;存放三个数码管的段码
LED_1 	EQU 	31H
LED_2 	EQU 	32H

ADC	EQU	35H			;存放转换后的数据
ST 	BIT 	P3.2
OE 	BIT 	P3.0
EOC 	BIT 	P3.1
	ORG 	00H

START: 	MOV	LED_0,#00H
	MOV	LED_1,#00H
	MOV	LED_2,#00H
	MOV	DPTR,#TABLE		;送段码表首地址

	SETB	P3.4
	SETB	P3.5
	CLR	P3.6		 	;选择ADC0808的通道3

WAIT: 	CLR 	ST
	SETB 	ST
	CLR 	ST				;启动转换
 	JNB 	EOC,$		 	;等待转换结束
	SETB 	OE 				;允许输出
	MOV 	ADC,P1			;暂存转换结果
	CLR 	OE			  	;关闭输出
	MOV 	A,ADC			;将AD转换结果转换成BCD码
	MOV 	B,#100
	DIV 	AB
	MOV 	LED_2,A
	MOV 	A,B
	MOV 	B,#10
	DIV 	AB
	MOV 	LED_1,A
	MOV 	LED_0,B

	LCALL	DISP		  	;显示AD转换结果
	SJMP 	WAIT

intov:  
	mov dptr,#tab
	mov a,adc 
	movc a,@a+dptr
	mov b,#2
	div ab
	mov r1,b
	mov b,#10
	div ab
	mov led_2,a
	mov led_1,b
	cjne r1,#01,kk1
        mov led_0,#05
back:   ret
kk1:    mov led_0,#00
        ajmp back	

	
DISP:	mov    dptr,#table
   	MOV	A,LED_0			;数码显示子程序
	MOVC	A,@A+DPTR
	CLR	P2.3
	MOV	P0,A
	LCALL	DELAY
	SETB	P2.3

        mov    dptr,#table
	MOV	A,LED_1
	MOVC	A,@A+DPTR
	CLR	P2.2
	MOV	P0,A
	LCALL	DELAY
	SETB	P2.2

        mov    dptr,#table
	MOV	A,LED_2
	MOVC	A,@A+DPTR
	setb    acc.7
	CLR	P2.1
	MOV	P0,A
	LCALL	DELAY
	SETB	P2.1
	RET
DELAY:	MOV	R6,#10			;延时5毫秒
D1:	MOV	R7,#250
	DJNZ	R7,$
	DJNZ	R6,D1

	RET

TABLE: 	DB 	3FH,06H,5BH,4FH,66H
	DB 	6DH,7DH,07H,7FH,6FH
	
tab:
db      0,      0   ,  	0   ,	1,	0,	2,	0,	0,	3,	0
db	4,	0,	0,	5,	0,	6,	0,	0,	7,	0
db	8,	0,	0,	9,	0,	0,	10,	0,	11,	0
db	0,	12,	0,	13,	0,	0,	14,	0,	15,	0
db	0,	16,	0,	17,	0,	0,	18,	0,	19,	0
db	0,	20,	0,	0,	21,	0,	22,	0,	0,	23

db	0,	24,	0,	0,	25,	0,	26,	0,	0,	27
db	0,	28,	0,	0,	29,	0,	0,	30,	0,	31
db	0,	0,	32,	0,	33,	0,	0,	34,	0,	35
db	0,	0,	36,	0,	37,	0,	0,	38,	0,	39
db	0,	0,	40,	0,	0,	41,	0,	42,	0,	0

db	43,	0,	44,	0,	0,	45,	0,	46,	0,	0
db	47,	0,	48,	0,	0,	49,	0,	50,	0,	0
db	51,	0,	0,	52,	0,	53,	0,	0,	54,	0
db	55,	0,	0,	56,	0,	57,	0,	0,	58,	0
db	59,	0,	0,	60,	0,	0,	61,	0,	62,	0
db	0,	63,	0,	64,	0,	0,	65,	0,	66,	0

db	0,	67,	0,	68,	0,	0,	69,	0,	70,	0
db	0,	71,	0,	0,	72,	0,	73,	0,	0,	74
db	0,	75,	0,	0,	76,	0,	77,	0,	0,	78
db	0,	79,	0,	0,	80,	0,	0,	81,	0,	82
db	0,	0,	83,	0,	84,	0,	0,	85,	0,	86

db	0,	0,	87,	0,	88,	0,	0,	89,	0,	90
db	0,	0,	91,	0,	0,	92,	0,	93,	0,	0
db	94,	0,	95,	0,	0,	96,	0,	97,	0,	0
db	98,	0,	99,	0,	0,	100,	0,	0,	0	
 END