Hello all, Today I made myself a nice and simple serial cable - TX, RX and ground (I don't need anything else), and it works well when I connect 2 laptops to each other, running HyperTerminal. Unfortunately, HyperTerminal does not record serial data sent by 2 different evaluation boards (MCBSTR7/9), running Keil / ST sample code. What can be the cause of this? Can it be related to the type of wire I used? Any ideas are welcome!
Thanks in advance
You need to swap RX and TX on one end of the cable.
The swap (based on the cable you have built) is not when talking PC to PC, but when you talk PC to Eval board you need to swap one end.
Robert, Thanks for your reply. Could you please explain further? I have made a null cable, of course. What do you mean exactly by "swap"?
Greetings, Tamir
Don't use a null cable to talk to the dev board. Go straight through.
Ok, I will try that tomorrow...thanks.
Hi Tamir,
if I understand you correctly you do the following:
RX---\ /------RX uC Board-1 X uC Board-2 TX---/ \------TX (null-modem cable)
As you can see from the figure above, you can only monitor one transmit channel at the time (uC Board-1 or uC Board-2). It is important to notice that if you connect the PC serial port transmitter line to the wrong wire, the two RS232 drivers will compete. The result is most probably that the PC driver will be stronger and your uC Board will not be seen on the RS232 bus.
PC monitoring serial link: RX---\ /------RX uC Board-1 X uC Board-2 TX---/ \---+--TX | |--RX PC serial port TX PC serial port (not required)
I hope this helps!
Frank
Note This message was edited to reduce width.
F D, Thanks for your reply. Actually, I am only connecting one evaluation board to a PC. I understand that I need to make a non-null cable for that - so that's what I'm going to do.
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