How To Interface An ADC0831 To The 8051

I already make an example of using temperature sensor with ADC0831 connect to  8051 .When you give heat at the temperature sensor and  the LCD display data temperature will be increase...

The ADC0831 series are 8-bit successive approximation A/D converters with a serial I/O and configurable input multiplexers with up to 8 channels. The serial I/O is configured to comply with the NSC MICROWIRE™ serial data exchange standard for easy interface to the COPS™ family of processors, and can interface with standard shift registers or µPs. The 2-, 4- or 8-channel multiplexers are software configured for single-ended or differential inputs as well as channel assignment. The differential analog voltage input allows increasing the common-mode rejection and offsetting the analog zero input voltage value. In addition, the voltage reference input can be adjusted to allow encoding any smaller analog voltage span to the full 8 bits of resolution.

List of equipment  

IMPORTANT: ANY CONNECTION SHOULD FOLLOW THE SCHEMATIC DIAGRAM TO AVOID THE COMPONENTS FROM DAMAGE. 

In ADC0831 interfacing, the Vin(+) is connect to analog pin data from sensor used and pin Vin (-) to ground. Three main pin CS, CLK and DO are connect to I/O microcontroller and Vref can be directly connect to VCC supply (+5VDC). The basic program for ADC0831 with 8051 is show below by according the timing pulse graph above. The data from ADC0831 only transfer to P1 as an output.

CLK        BIT    P1.1
CS        BIT    P1.0
DO        BIT    P1.2

ORG 00H
        MOV    P2,#00H    
SENS1:    MOV    R0,#8
        CLR    CS
UP:        CLR    CLK
        ACALL    DELAY
        SETB    CLK
        ACALL    DELAY
        MOV    C,DO
        RLC    A
        DJNZ    R0,UP
        SETB    CS
        MOV    P2,A
        MOV R7,A
        AJMP    SENS1
        END


First of all I made a schematic circuit in Proteus and  write program in Keil Uvision3 and perform simulation.You can see circuit that i have make.After finish and record the value of display i build circuit on bredboard.

Circuit 

Program 

CLK        BIT    P1.1
CS        BIT    P1.0
DO        BIT    P1.2

        ORG     00H
        MOV     A,#38H
        ACALL     COMNWRT
        ACALL     DELAY
        MOV     A,#0EH
        ACALL     COMNWRT
        ACALL     DELAY
        MOV        A,#01
        ACALL     COMNWRT
        ACALL    DELAY
        MOV     A,#06H
        ACALL     COMNWRT
        ACALL     DELAY
   
                   
   
        MOV        P2,#00H    
SENS1:    MOV        R0,#8
        CLR        CS
UP:        CLR        CLK
        ACALL    DELAY
        SETB    CLK
        ACALL    DELAY
        MOV        C,DO
        RLC        A
        DJNZ    R0,UP
        SETB    CS
        MOV        P2,A
        MOV     R7,A
        ACALL    CONVT
        AJMP    SENS1
 CONVT:    MOV     A,#84H
        ACALL     COMNWRT
        ACALL     DELAY

         MOV    A,R7
        MOV B,#10
        DIV AB
        MOV R3,B
        MOV B,#10
        DIV AB
        MOV    R2,B
        MOV    R1,A
            CLR    A
            MOV    A,#30H
            ADD    A,R1
            MOV    R1,A  
            CLR    A
            MOV    A,#30H
            ADD    A,R2
            MOV    R2,A
            CLR    A
            MOV    A,#30H
            ADD    A,R3
            MOV    R3,A  
           
           
           
               
            MOV    A,#"T"
            ACALL    DATAWRT
            MOV    A,#"E"
            ACALL    DATAWRT
            MOV    A,#"M"
            ACALL    DATAWRT
            MOV    A,#"P"
            ACALL    DATAWRT
            MOV    A,#":"
            ACALL    DATAWRT
            MOV    A,R1
            ACALL    DATAWRT
               MOV    A,R2
            ACALL    DATAWRT
            MOV    A,R3
            ACALL    DATAWRT
            MOV    A,#"'"
            ACALL    DATAWRT
            MOV    A,#"C"
            ACALL    DATAWRT
            RET

COMNWRT:MOV     P2,A
        CLR     P3.5
        CLR     P3.6
        SETB     P3.7
        ACALL     DELAY
        CLR     P3.7
        RET
DATAWRT:MOV     P2,A
        SETB     P3.5
        CLR     P3.6
        SETB     P3.7
        ACALL     DELAY
        CLR     P3.7
        RET

       
DELAY:    MOV        40H,#120
HERE1:    MOV        41H,#250
TERUS:    DJNZ    41H,TERUS
        DJNZ    40H,HERE1
        RET
        END