http://www.8051projects.net/ Learn to make simple microcontroller projects, pic, 8051, avr and arm projects. download 8051 projects, tutorials, libraries, sample codes. join the microcontroller discussion forum and ask doubts regarding electronics. the best source for 8051 over internet. en-gb 2009-01-08T10:42:14-08:00 contact@nospam.com hourly 1 2000-01-01T12:00+00:00 http://www.8051projects.net/forum-t11188.html 2009-01-08T10:42:14-08:00 I want to send characters to Hyperterminal from 8051. Please let me know if my connections and code are right.8051 TX -> MAX232 T1in.... MAX232 T1out -> PC RX=====9600 baud. 11.0592 MHz. 8 bits. 1 stopbit. No parity.CODE:
clr sm0
setb sm1
MOV TMOD, #20H
MOV TH1, #253
MOV A, PCON            
clr ACC.7              
MOV PCON, A     
mov SCON, #50H ;8b, 1stop, 1start, REN enabled
GAIN: mov SBUF, #'A' ;letter A is transmitted
HERE: jnb TI, HERE
clr TI
sjmp GAIN
endThanks http://www.8051projects.net/forum-t11188.html 2009-01-08T10:42:14-08:00 Arun Kumar V Hi Mac, the max232 connection seems to be correct, the code doesn't work bcoz you haven't started the timer1, here's the modified code:CODE:MOV TMOD, #20H
MOV TH1, #253
ANL PCON,#7FH  
MOV SCON, #50H ;8b, 1stop, 1start, REN enabled
SETB TR1

GAIN: MOV SBUF, #'A' ;letter A is transmitted
HERE: jnb TI, HERE
clr TI
sjmp GAIN
endall the best !Arun http://www.8051projects.net/forum-t11188.html 2009-01-08T10:42:14-08:00 sashijoseph Connections are OK.In the code you've forgotten to start the timer (setb TR1).Some lines are superfluous...since you've already set SCON to 50H there's no need to explicitly clr and set smo and sm1.On reset,the PCON D7 bit is cleared automatically,so you can do away with those 3 lines as well.EDIT : Seems Arun and I posted at the same time.. http://www.8051projects.net/forum-t11188.html 2009-01-08T10:42:14-08:00 Colin Mac ok thanks a lot guys http://www.8051projects.net/forum-t11188.html 2009-01-08T10:42:14-08:00 Colin Mac That worked. Now I'm trying to send 'A' from one micro to another to turn on a led. Can you let me know if you see a problem? CODE:
MOV TMOD, #20H
MOV TH1, #244 ;2400
ANL PCON,#7FH  
MOV SCON, #50H ;8b, 1stop, 1start,
SETB TR1

send:
MOV SBUF, #'A' ;letter A is transmitted
jnb TI, $
clr TI
jmp send
endCODE:
MOV TMOD, #20H
MOV TH1,  #244  ;2400
ANL PCON, #7FH  
MOV SCON, #50H ;8b, 1stop, 1start, REN enabled
SETB TR1

setb p1.7
start:
JNB RI, $ ; wait for an entire byte to be received
CLR RI ; the receive interrupt flag is set by hardware but must be cleared by software
MOV A, SBUF;
CJNE A, #'A', start
clr p1.7
jmp $
end
  http://www.8051projects.net/forum-t11188.html 2009-01-08T10:42:14-08:00 sashijoseph seems ok.... http://www.8051projects.net/forum-t11188.html 2009-01-08T10:42:14-08:00 Colin Mac I think it's working now. Cheers.