USB reset question

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
I have been observing unexpected USB resets in a product I am
troubleshooting.  The board has three USB devices internal to itself:  a 2.0
hub chip, a PIC18F4550 which I programmed, and a touch panel circuit.
Everything works fine until we attach another device to the hub - a
mouse-keyboard combination custom-designed for the overall product.  Then I
see all three USB devices (the PIC, the touch panel, and the mouse-keyboard)
are USB-reset every 2-5 minutes.

Reading through the spec and a couple of USB design books, it seems to me
that the USB reset is normally originated by the USB root/host computer.  Is
it reasonable that that computer would issue resets to devices?  Is it
possible that my hub chip is doing it on its own?

Re: USB reset question
Check the current draw. It can not exceed 100ma.

Quoted text here. Click to load it
Quoted text here. Click to load it

Re: USB reset question

Quoted text here. Click to load it

All the devices are self-powered, but that is worth checking.

Quoted text here. Click to load it

Site Timeline