Hi,

I have a 89C51RD+ development board, I have been learning making small programs and debugging them on the board. Now I am starting learning serial communication but I am having problem receving a character from the board to my pc which I have connected through RS232.

I have written the following code in Visual Basic to receive the character:

MSComm1.Settings = "9600,N,8,1"
MSComm1.CommPort = 1
MSComm1.PortOpen = True
Text1.Text = MSComm1.Input

Simultaneously I have programmed the Chip to transmit data through TxD pin the code is:


;TRANSMISSION
mov scon,#h'50 ; Serial port in mode 1
mov tmod,#h'20 ; Set up timer 1 in mode 2 (autoreload) ...
mov th1,#h'FC ; TO SET UP BAUD RATE
mov tl1,#h'FC

setb tr1
mov a,#h'45
loop: ; Send P1 contents continuously
mov sbuf,a
again: jnb TI,again
clr TI
sjmp loop


After running the program i am not receiving any character in the text box. what is the problem??? Although on short(connecting) the RXD and TXD pin and running the VB program I am getting the data outputted. but not with 89C51RD+. I am using simple development board with only RXD,TXD and ground pin to the RS232 (9 pin)connector. Hence I am working with simple serial transmission and not with Handshaking one.
Can someone help me or simply show me a code to transmit a single character to PC from 89C51RD+ ???