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8051 coding problem for a light bulb control

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Rockyvud

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I have been trying to control a light bulb through computer interface and usign 8051 microcontroller.I think i am wrong somewhere in microcontroller programming,can someone tell me where? following is the program

org 00h
mov p2,#00H
mov tmod,#20H
mov scon,#50H
mov th1,#
setb tr1
scan:
jnb ri,$
mov p2,sbuf
clr ri
jmp scan
end,
 

Re: 8051 coding problem

What is your BaudRate ..
MOV TH1,# what?

Code: 
                       1    $NOPAGING
                       2    $MOD252
                       3    
0000                   4            org 00h
                       5    
0000 75A000            6            mov p2,#00H 
0003 7404              7            MOV A, #04h             ; 9600bps ..
0005 120012            8            LCALL Ser_Setup
                       9     
0008                  10    scan: 
0008 3098FD           11            jnb ri,$ 
000B 8599A0           12            mov p2,sbuf 
000E C298             13            clr ri 
0010 80F6             14            jmp scan
                      15    
                      16    ; =====================================================================
                      17    ; Initialize Serial communications  A=Baud Rate
                      18    ; With cristal oscillator of 11,059,200 value for auto-reloded Timer1 is calculated using the
                      19    ; following formula: 256-57600/BaudRate=TH1
                      20    ; Full formula: 256-[2pwrSMOD/32]*[SC/(12*BaudRate)]
                      21    
0012                  22    Ser_Setup:      
0012 758780           23                    MOV     PCON, #80h
0015 759852           24                    MOV     SCON, #52h
0018 758920           25                    MOV     TMOD, #20h
001B 900024           26    SetNewBaud:     MOV     DPTR, #BAUDRATE
001E 93               27                    MOVC    A, @A+DPTR
001F F58D             28                    MOV     TH1, A
0021 D28E             29                    SETB    TR1
0023 22               30                    RET
                      31    
0024 FF               32    BAUDRATE:       DB   0FFh               ; 57600         0
0025 FE               33                    DB   0FEh               ; 28800         1
0026 FD               34                    DB   0FDh               ; 19200         2
0027 FC               35                    DB   0FCh               ; 14400         3
0028 FA               36                    DB   0FAh               ; 9600          4
0029 F4               37                    DB   0F4h               ; 4800          5  
002A E8               38                    DB   0E8h               ; 2400          6
002B D0               39                    DB   0D0h               ; 1200          7
002C A0               40                    DB   0A0h               ; 600           8  
002D 40               41                    DB   040h               ; 300           9
                      42    
                      43    
                      44    ; ====================================================================
                      45    
                      46            end

VERSION 1.2h ASSEMBLY COMPLETE, 0 ERRORS FOUND
BAUDRATE . . . . . . . . . . . .  C ADDR  0024H  
P2 . . . . . . . . . . . . . . .  D ADDR  00A0H  PREDEFINED  
PCON . . . . . . . . . . . . . .  D ADDR  0087H  PREDEFINED  
RI . . . . . . . . . . . . . . .  B ADDR  0098H  PREDEFINED  
SBUF . . . . . . . . . . . . . .  D ADDR  0099H  PREDEFINED  
SCAN . . . . . . . . . . . . . .  C ADDR  0008H  
SCON . . . . . . . . . . . . . .  D ADDR  0098H  PREDEFINED  
SER_SETUP. . . . . . . . . . . .  C ADDR  0012H  
SETNEWBAUD . . . . . . . . . . .  C ADDR  001BH  NOT USED  
TH1. . . . . . . . . . . . . . .  D ADDR  008DH  PREDEFINED  
TMOD . . . . . . . . . . . . . .  D ADDR  0089H  PREDEFINED  
TR1. . . . . . . . . . . . . . .  B ADDR  008EH  PREDEFINED

Regards,
IanP
 

    R

    Rockyvud

    Points: 2
    Helpful Answer Positive Rating
8051 coding problem

Baud rate is 9600 bps.




MOV TH1,# -3
Is this right for getting 9600 baudrate?
 

Re: 8051 coding problem

Rockyvud wrote:
MOV TH1,# -3
Is this right for getting 9600 baudrate?
Click to expand...

MOV TH1,# -3 is right for getting 9600 baudrate if fXTAL = 11.0592 MHz and if bit SMOD == 0. (SMOD = PCON.7)
 

8051 coding problem

Try these,

MOV SCON,#50H
MOV TMOD,#20H
MOV TH1,#0FDH ;for 9600 baud rate n 11.0592MHZ
SETB TR1

Added after 1 minutes:

ALSO I USE TO CALL SOME DELAY ROUTINE BEFORE SBUF (if there is a loop)
 

8051 coding problem

Basic '51 UART troubleshooting:
**broken link removed**

wek
 

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