Need a NULL Modem cable

Hi,

Sorry for unrelated question.
I need a NULL modem (RS232 DB9F-DB9F) cable to connect beagleboard to USB to serial converter.
Can anyone on list advised me from where can I have this cable in India (specially in Delhi)?

Thanks,
Chetan Nanda

Chetan,
The null modem cable is fairly available peripheral. You should get it in any electronics shop. I am not sure about Delhi, but if you are in Bangalore SP road is the place to get it.

2009/12/2 Chetan Nanda <chetannanda@gmail.com>

Or make one yourself… I’ve done it so many times I can still remember the pinout:

Solder pin 2 on one connector to pin 3 on the other, 3 to 2 and 5 to 5. Gives you the basics (Rx, Tx and Ground)

Then you can add 4 to 6, 6 to 4, 7 to 8 and 8 to 7 to cover the handshaking control

There seems no real consensus on what to do with pins 9 and 1.

Or make one yourself… I’ve done it so many times I can still remember the pinout:

Solder pin 2 on one connector to pin 3 on the other, 3 to 2 and 5 to 5. Gives you the basics (Rx, Tx and Ground)

Then you can add 4 to 6, 6 to 4, 7 to 8 and 8 to 7 to cover the handshaking control

Thanks Edward, but
On http://en.wikipedia.org/wiki/File:D9_Null_Modem_Wiring.png it shows:

1,6 → 4
and 4 → 1,6

rest are same as mentioned. So What should be the final pinout?

I would check the System Reference Manual.

http://beagleboard.org/static/BBSRM_latest.pdf

Gerald

I would check the System Reference Manual.

http://beagleboard.org/static/BBSRM_latest.pdf

Hi Gerald,

I have a quick look at reference manual, what I have understood from this is:

  1. Beagleboard implement pin 2, 3, and 5 for serial port.
  2. So on Null modem connector side swapping pin 2 and 3 would be sufficient enough.

Does my understanding is correct?

Thanks,
Chetan Nanda

  1. Beagleboard implement pin 2, 3, and 5 for serial port.
  2. So on Null modem connector side swapping pin 2 and 3 would be sufficient enough.

Plus ground 5-5 is necessary

Yes. Although, you may find that it can work without it, but I would not recommend it.

Gerald