XBox 360 power question

My FEZ Domino works perfect. I created a nice clock app with an LCD.

I attached it to my XBox 360 USB port, but the app doesn’t seem to run properly. The backlight comes up, and the fez power led comes up, but nothing comes up on the display. To verify I took out the demo app (blink internal light). On PC usb power (my workstation, server, and laptop) it works. On the PC’s USB, I get around 4.66v. on the +5 pin.

On the 360 however, I get 4.67v, and 3.3v on the pins, but the led does not blink.

Why are you trying to plug it into an X-Box 360?

Why? I expected that question.

For no other reason than having a power supply in another location. I am not making anything xbox related. USB power is USB power right?

Can you measure the ma coming from the port. I would expect amperage to be the issue not the voltage.

Maybe your setup and the XBOX draws too much power. Connect a power supply.
Are you sure it is not a software problem? Debug in Visual Studio what happens?

You might find (untested by me) that XBOX 360 is not a full and generic USB controller, so it may choose to not supply power to a USB device that it does not recognise as a controller or other device that is needed for “gaming”. If you have a spare USB cable lying around and are willing to try it, you could break the cable and remove the USB data lines, so that the only thing that you draw from the USB port on the xbox is power.

Since the backlight of my project does light up, and I can sense proper voltages, I must be amps logically. I just thought to find a cheap and easy power source near my TV since I lack a proper wall-wart…

I don’t own any consoles, but i would have thought that the xbox would be able to provide a decent bit of current considering it’s dual shock/rumble function uses 500+ma of power which causes most PC ports to brownout…

Brett is right! Even on a PC you have to install drivers or it wont even supply a voltage… you have to either ground or keep high ( I dont remeber which ) the +D pin to use it as a power supply ( Read the documentation before doing this ). Quite a lot of Phones and peripherals do this… Its kind of a fail safe…

The other reason maybe its looking for the drivers for the domino device (You know how long that takes. It is Microsoft ) before releasing the USB port…

Cheers Ian

P.S. Warning!! Wall socket adaptors may provide highr than 5V ( ie… phone chargers )