8051 Serial UART Problem

A

ahmedragia21

Member

• Dec 14, 2007

• #1

Hi im using 89S52 UART With max232 , the transmitter to pc works fine to hyber terminal but the reciever doesnt work , and the code works fine on the keil UART simulator ! i dont know why the reciever doesnt work , is there a setup for hyber terminal to let the reciever work ?

thanks

 

K

kchriste

New Member

Forum Supporter

• Dec 14, 2007

• #2

Try setting handshaking to NONE in "hyber terminal" if you haven't already.

 

A

ahmedragia21

Member

• Dec 14, 2007

• #3

thanks for the reply
what's handshaking i didnt put it to NONE in hyperterminal ..
how to do it
so do u think the problem isnt in the hardware ?

 

K

kchriste

New Member

Forum Supporter

• Dec 14, 2007

• #4

It is one thing of many that could be wrong but the easiest to fix.
Look here:

 

Attachments

• HT.PNG

  68.3 KB · Views: 614

A

ahmedragia21

Member

• Dec 14, 2007

• #5

the Tx to pc is working but from pc to the micro it doesnt
is this is problem ?

thanks again

 

A

ahmedragia21

Member

• Dec 15, 2007

• #6

i set the handshaking to none and still the hyber doesnt send charachters :S and the micro doesnt recieve...
is there a test to make sure the circuits are working ?

 

K

kchriste

New Member

Forum Supporter

• Dec 15, 2007

• #7

You can check that the pins on the MAX232 have the following voltages:
Pin 16 = +5V
Pin 2 = +9V
Pin 6 = -9V
Pin 15 = 0V (ground reference for above measurements)

Without a diagram it is hard to tell which input on the MAX232 your are using, but when the PC sends data to the PIC you should get activity on either pins 8&9 or pins 12&13 of the MAX232.