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01/20/09 12:59
Modified:
  01/20/09 13:19

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#161634 - Serial Communication Problems
Hi 8051 experts. I am a newbie in this field. Can you pls help me why I can't make the circuit below to work? Pls tell me what is wrong with it. I also included the program. It might help.

Thanks in advance,
Bing Lo


 ORG     00H            ; Reset
 sjmp start
 start:
    MOV TMOD,#20H        ;enable timer1, mode 2 (auto reload)
    MOV TH1,#0FDH        ;9600 Baud rate
    MOV SCON,#50H        ;8 bit, 1 stop bit, REN enabled
    SETB TR1
again: mov r1, #0dh
 mov dptr,#date1
AGAIN1:movc a,@a+dptr            ;Read P0
inc dptr
    MOV SBUF,A            ;send data
HERE:JNB TI,HERE            ;wait for data to be transferred
    CLR TI            ;clear TI for next char
 djnz r1, again1
    SJMP AGAIN            ;keep doing it
date1: db "Hellow World!"

	end
 



List of 34 messages in thread
TopicAuthorDate
Serial Communication Problems            01/01/70 00:00      
   standards have a purpose            01/01/70 00:00      
      Serial Communication Problem            01/01/70 00:00      
         OH, how often            01/01/70 00:00      
   No negative Tx supply            01/01/70 00:00      
      Serial Communication Problem            01/01/70 00:00      
   Software or documentation bug            01/01/70 00:00      
      I am so new sorry            01/01/70 00:00      
         Reset            01/01/70 00:00      
   I found this Image at google            01/01/70 00:00      
      Read datasheets to better understand            01/01/70 00:00      
      which derivative            01/01/70 00:00      
      It will meet the RS232 requirements            01/01/70 00:00      
         Are You sure?            01/01/70 00:00      
            are you saying "PC" when you say "mother board"            01/01/70 00:00      
               You are right , Eric,            01/01/70 00:00      
                  because            01/01/70 00:00      
                     cheap is paradigm today, so            01/01/70 00:00      
                        That's odd ... I've never seen one ...            01/01/70 00:00      
                           odd, but real .            01/01/70 00:00      
                              Explaining to beginners            01/01/70 00:00      
                                 agree            01/01/70 00:00      
                           look for a copy of the EIA standard and read it            01/01/70 00:00      
                           right, but not the issue            01/01/70 00:00      
            RS-232 transceiver in PC            01/01/70 00:00      
   Basics            01/01/70 00:00      
      MAX232 vs DS275            01/01/70 00:00      
         It is not that simple            01/01/70 00:00      
            I bought the required componentss            01/01/70 00:00      
               It worked! Yahoo!!!!Googlooo!!!            01/01/70 00:00      
   Circuit Design            01/01/70 00:00      
      May need to have pullup resistors            01/01/70 00:00      
         It worked, thanks!            01/01/70 00:00      
            It destroyed though my red led            01/01/70 00:00      

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