8051 Serial UART Problem - Electronic Circuits Projects Diagrams Free

ahmedragia21 · 15th December 2007, 04:38 AM

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

kchriste · 15th December 2007, 06:14 AM

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

ahmedragia21 · 15th December 2007, 06:17 AM

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 ?

kchriste · 15th December 2007, 06:39 AM

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

Look here:

ahmedragia21 · 15th December 2007, 06:40 AM

the Tx to pc is working but from pc to the micro it doesnt

is this is problem ?

thanks again

ahmedragia21 · 15th December 2007, 09:04 PM

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 ?

kchriste · 16th December 2007, 12:27 AM

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.

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15th December 2007, 04:38 AM	#1
ahmedragia21	8051 Serial UART Problem 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

15th December 2007, 06:14 AM	#2
kchriste	Try setting handshaking to NONE in "hyber terminal" if you haven't already. __________________ Inside every little problem, is a big problem trying to get out.

15th December 2007, 06:17 AM	#3
ahmedragia21	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 ?

15th December 2007, 06:39 AM	#4
kchriste	It is one thing of many that could be wrong but the easiest to fix. Look here: Attached Thumbnails __________________ Inside every little problem, is a big problem trying to get out.

15th December 2007, 06:40 AM	#5
ahmedragia21	the Tx to pc is working but from pc to the micro it doesnt is this is problem ? thanks again

15th December 2007, 09:04 PM	#6
ahmedragia21	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 ?

16th December 2007, 12:27 AM	#7
kchriste	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. __________________ Inside every little problem, is a big problem trying to get out.