[beagleboard] Some Junk characters on serial port

I am using idotconnect USB-to serial adapter on my windows xp m/c,
when I power on board get some junk characters on the serial console.

Serial settings are configured correctly.

You will get junk characters when the board first boots as it is looking for a serial download utility. After that, the board should boot and the characters will make more sense. Does your board boot to where the LEDS come on?


1) Yes,board boots to 2 user LEDs glow. Also I have connected HDMI
cable to TV and I get Angstrom login prompt.

2) This serial downlaod utility board gets from internet location?.
3) If so do the board needs to connect to internet when it boots?

4) I am trying to get UBOOT messages on console.


It sounds like the board is booting fine, but that you do not have the correct cable configuration on your serial port. I suggest you refer to section 13 of the System Reference Manual to check out your cable configuration. Most likely issues are:

  1. Wrong ribbon cable.
  2. Ribbon cable plugged in to the board backwards
  3. Not using a null modem cable between the ribbon cable and the PC.

The board will connect to the internet if you have an Ethernet or WIFI adapter plugged in and your Linux distribution is set up correctly. There is no need for the card to connect to the Internet in order for your serial port to work.


1) I am using Null modem cable.
2) Might be that AT/Everex cable might be wrong, got it from Frys.

I am getting some characters that means Null modem cable is fine and
also USB-Serial adapter cable is fine.?


Well, if you got it from Frys, then most likely you got the wrong version. I have never seen the correct version at Frys. They typically stock the Intel version. If this is the case, you would get characters but won’t be able to send anything back to the board.


IDC10 cable I got it from Frys.

E.g http://www.frys.com/product/1066553?site=sr:SEARCH:MAIN_RSLT_PG

I purchased DB9 but of the same type.

You think thats the problem?

You know from where I should order the correct IDC10 cable.

Digi or Special Computing?


I would go with Special Computing. Their stuff works.


I had the same problem.

Set speed to be 115200 baud, then it’ll work.

Good luck!


You can keep the cable you got at Frys; just open it up and solder the ribbon cable
to the right pins on the back of the DB9 connector.

Looking at the back of the DB9 connector, each pin is numbered. The wire with the red stripe on the ribbon cable is wire #1. Solder the the wire with the red stripe to pin 1, then solder wires 2 through 9 to pins 2 through 9.