Tuesday, 25 May 2010

Received my BeagleBoard!

This morning I received a package from Digikey (thanks to Cathy!), with a BeagleBoard, a 5V power adapter, and a IDC10-DB9 cable.

I connected the BeagleBoard to my PC, using the ICD10-DB9 cable, followed by a USB->RS232 adapter. Then I powered it on, some leds blinked, and, nothing on the terminal... I then tried connecting it to another PC, with a serial port, nothing again.

I started wondering if I needed a null-modem cable, so I checked the pinout on the ICD10-DB9 to check if it wasn't one already. And I realised that the pinout was completely non-sensical (ground connected to RX, ring signal connected to TX)... Since the colors on the RS232 wires are not standardized, it looks like the people who built the cable did not realize that the colors changed with their latest supply of cables...

It seems like the problem affect quite a few people who ordered the cable recently, so here is how to fix it:
  • Take out all the wires from the ICD10 connector (easy to do with a needle).
  • The red and green wires should be together on one pin. Cut the green one.
  • Then, connect the red wire (TX, pin 3) on pin 2 of the BeagleBoard (RX).
  • The brown one (RX, pin 2), on pin 3 of the BeagleBoard (TX).
  • The yellow one (GND, pin 5), on pin 5 of the BeagleBoard.
  • Leave the other wires dangling, you don't need them (beware of shorts though, I taped them to avoid problems).
A picture of what it looks like in the end:

Note that this is only for this batch of cables, and it's always better to check the wiring with a ohmmeter, if you have one (the RS232/DB9 pinout can be found here).

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