8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes : Forum / topic 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 Creative Commons LicenseThis work is licensed under a Creative Commons Attribution-Noncommercial 2.5 India License.Rickey's World Disclaimer Ajay Bhargav - contact@nospam.com contact@nospam.com Mon, 01 Dec 2008 11:53:17 -0800 Mon, 01 Dec 2008 11:53:17 -0800 http://backend.userland.com/rss e107 (http://e107.org) 60 Search Search 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes query http://www.8051projects.net/search.php serial interfacing doubt. http://www.8051projects.net/forum-t10320.html
ORG 00H
MOV TMOD,#20H
MOV TH1,#0FDH
MOV TL1,#0FDH
MOV SCON,#50H
SETB TR1

READ: JNB RI,READ
MOV A,SBUF
CJNE A,#0FFH,CLEAR
CLR RI

WAIT: JNB RI,WAIT
MOV A,SBUF
CJNE A,#00H,NXT
CLR P1.7
SJMP DOWN

NXT: CJNE A,#01H,DOWN
SETB P1.7

CLEAR: CLR RI
SJMP HERE
END
]]> Wed, 25 Jun 2008 08:54:23 -0700 http://www.8051projects.net/forum-t10320.html Re: serial interfacing doubt. http://www.8051projects.net/forum-t10320.html
in your program you are comparing the incoming characters to some fixed ones and switching LED on/off.

you have defined some labels/segments which are not present in your code like :

ORG 00H
MOV TMOD,#20H
MOV TH1,#0FDH
MOV TL1,#0FDH
MOV SCON,#50H
SETB TR1

READ: JNB RI,READ
MOV A,SBUF
CJNE A,#0FFH,CLEAR
CLR RI

WAIT: JNB RI,WAIT
MOV A,SBUF
CJNE A,#00H,NXT
CLR P1.7
SJMP DOWN

NXT: CJNE A,#01H,DOWN
SETB P1.7

CLEAR: CLR RI
SJMP HERE
END


data sent over serial port will be in ASCII format, so its better to compare with known ASCII letters than HEX values for eg: a b c


a modified code looks like this:

CODE:
ORG 00H

MOV TMOD,#20H
MOV TH1,#0FDH
MOV TL1,#0FDH
MOV SCON,#50H
SETB TR1

SETB P1.7

READ: JNB RI,READ
MOV A,SBUF
CLR RI
CJNE A,#'A',NOTA       ;  if it is "A" then the LED glows
CLR P1.7
SJMP READ

NOTA: CJNE A,#'B',READ
SETB P1.7                   ; if its "B"  LED is off
SJMP READ                 ; if you enter any other letters/nums it just ignores

END
 
]]> Arun Kumar V<nura1002003@nospam.com> Wed, 25 Jun 2008 18:13:08 -0700 http://www.8051projects.net/forum-t10320.html Re: serial interfacing doubt. http://www.8051projects.net/forum-t10320.html oreo<witchkingx@nospam.com> Thu, 26 Jun 2008 04:06:49 -0700 http://www.8051projects.net/forum-t10320.html Re: serial interfacing doubt. http://www.8051projects.net/forum-t10320.html
you can either use 'A' or 41H, because the compiler ultimately converts all Ascii, Decimal, binary values into hex.

i had used Edsim51 last year,it looked good but not very flexible. the code i gave works well and has been tested on some other sim called 80513 Simulator. here are the test results:

When 'A' is pressed - P1.7 is 0






When 'B' or any other letter is pressed P1.7 is 1




i'll try it on Edsim51 tonight..........

one more thing, in our forum we have a Thanks giving Button, if you find the replies helpful you can press the Thanks button


Arun]]> Arun Kumar V<nura1002003@nospam.com> Thu, 26 Jun 2008 06:11:37 -0700 http://www.8051projects.net/forum-t10320.html Re: serial interfacing doubt. http://www.8051projects.net/forum-t10320.html oreo<witchkingx@nospam.com> Fri, 27 Jun 2008 20:17:24 -0700 http://www.8051projects.net/forum-t10320.html Re: serial interfacing doubt. http://www.8051projects.net/forum-t10320.html
Private Sub Form_Load()
On Error Resume Next
MSComm1.CommPort = 1
MSComm1.Settings = "9600,N,8,1"
MSComm1.DTREnable = False
MSComm1.PortOpen = True
End Sub

Private Sub cmdsend_Click()
Dim LED As Long
If opton.Value = True Then
LED = A
Else
LED = B
End If
MSComm1.Output = Char$(LED)
End Sub

Private Sub Form_Unload(Cancel As Integer)
MSComm1.PortOpen = False
End Sub
]]> oreo<witchkingx@nospam.com> Mon, 30 Jun 2008 08:49:18 -0700 http://www.8051projects.net/forum-t10320.html