"Jona Vark" <noemail@all.com> wrote in message
news:EuOcf.14850$tV6.1691@newssvr27.news.prodigy.net...
> Check the current draw. It can not exceed 100ma.

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

> "Richard Henry" <rphenry@home.com> wrote in message
> news:3thk9hFstq5mU1@individual.net...
> > 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?
> >
> >
>
>

Check the current draw. It can not exceed 100ma.


"Richard Henry" <rphenry@home.com> wrote in message
news:3thk9hFstq5mU1@individual.net...
> 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?
>
>

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?