The speed at which analog input is converted to digital output depends on the speed of clk input.
According to datasheets of ADC0804 the typical operating frequency is 640khz at 5 volts. there are 2 ways to provide clock
source to ADc0804. as shown in fig.
According to datasheets of ADC0804 the typical operating frequency is 640khz at 5 volts. there are 2 ways to provide clock
source to ADc0804. as shown in fig.
ADC0804 with self clocking |
ADC0804 with 8051 crystal clocking |
Programming
; P2.5 CONNECTED TO RD
; P2.6 TO WR
; P2.7 TO INTR
; WR IS USED FOR STARTING CINVERSION
; SHOULD GO FROM L - H FOR CI=ONVERSION TO START
; CLR RD TO START READING DATA
ORG 0000H
RD BIT P2.5
WR BIT P2.6
INTR BIT P2.7
MYDATA EQU P1 ; DATA BUS OF ADC0804
MOV P1,#0FFH ; MAKE P1 INPUT
SETB INTR
BACK :
CLR WR
SETB WR
HERE :
JB INTR, HERE ; WAIT FOR END OF CONVERSION
CLR RD ; START READING
MOV A, MYDATA ;
ACALL CONVERSION; YOUR CONVERSION HEX - ASCCII
ACALL DISPLAY ; DISPLAY DATA
SETB RD ; RD =1 FOR NEXT ROUND
SJMP BACK ;
; P2.5 CONNECTED TO RD
; P2.6 TO WR
; P2.7 TO INTR
; WR IS USED FOR STARTING CINVERSION
; SHOULD GO FROM L - H FOR CI=ONVERSION TO START
; CLR RD TO START READING DATA
ORG 0000H
RD BIT P2.5
WR BIT P2.6
INTR BIT P2.7
MYDATA EQU P1 ; DATA BUS OF ADC0804
MOV P1,#0FFH ; MAKE P1 INPUT
SETB INTR
BACK :
CLR WR
SETB WR
HERE :
JB INTR, HERE ; WAIT FOR END OF CONVERSION
CLR RD ; START READING
MOV A, MYDATA ;
ACALL CONVERSION; YOUR CONVERSION HEX - ASCCII
ACALL DISPLAY ; DISPLAY DATA
SETB RD ; RD =1 FOR NEXT ROUND
SJMP BACK ;
CONVERSION :
; ANY HEX TO ASCII CONVERSION PROGRAM WILL DO.
DISPLAY :
; AS NO DISPLAY THEREFORE NOT TO BE USED
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