Changing Domino Debug Mode


So since my Domino didn’t come with a jumper for changing the debug mode, I was wondering which pin I have to short to ground to enable serial port debugging?

EDIT: Ok so I know it’s PWM 4, my question is about how I go about shorting it since there is no jumper.

You can use a short length of wire…

If you have an old pc lying around, just grab a jumper off it’s motherboard. ;D

A while ago I have stripped all jumpers of every motherboard I had lying around. These things come in handy everywhere :smiley:

PC jumper isn’t going to work for him since the pin is just a pad, he really does need a length of wire. Unless that is, he solders headers there.


That’s not totally correct. there is a mode jumper place ready on the board. Take a look at the board.board.


Hi Joe, actually it is :wink:

There is a pad that you can short, but they were talking about using a PC jumper to short it. Unless you solder headers onto that pad, you can’ use a PC jumper.

That’s right. The documentation says that there is a jumper, but there are no pins where this jumper should be. So I just assumed that there was another way. So then either mine didn’t come with a jumper or…

Time to warm up the soldering iron :frowning: sigh since I want to be able to go back to using USB on the fly.

Just to be sure, you have seen it.

When you use the mode pin’s you cant use the Led anymore.
It uses the same pin.


Just to be sure, you have seen it.

When you use the mode pads, you cant use the on-board Led anymore.
It uses the same pin.


BTW The jumper is only needed on system (FEZ Domino) boot-up. You can remove the jumper right after that and your LCD will work again. 8)

What jumper? It’s just pads :frowning:

Instead of jumper, put 1K resistor and the pin will always be functional

1K ohm across the pads? Or from the signal pad to ground

The second pad is ground so it is the same thing :slight_smile:

Just a few quick question regarding this.

  1. why would someone want to debug via serial?
  2. When debugging in serial, which COM port do you connect to?


To use USB for something else. See ebook USB Client section

Always COM1

OK so I’m soldering some pins onto the pads marked “Mode” and then I’m using a jumper across them (or a 1K ohm resistor).

Sounds ok.

Thanks Gus.

Oh great, as you would know I have fried my COM1. :-[ :’(

Side topic: how did you fry your com1 with out damaging the chip completely?

So Gus, once I remove the jumper and reboot the Domino will go back to USB debugging right?