Re: USB interface question.


petrus bitbyter wrote:
"siliconmike" <siliconmike@xxxxxxxxx> schreef in bericht
news:1149930411.747592.301740@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I'm newbie at USB, if someone can help it would be wonderful:

I'm envisioning a gadget that would take input from a USB port on a PC
(or any USB host). And it would act as a UPS for four downstream USB
devices, providing currents upto 1A.

In other words, the gadget would have 4 USB sockets for output, capable
of providing upto 1A to devices connected to it.

I have done some reading on USB but would like to ascertain whether the
gadget needs to have a controller / or can it be a passive device, as
far as the USB interface circuitry is concerned ?

(of course, the gadget would have its own separate supply, from where
it will derive the UPS power)

-Mike


Mike,

Buy a simple externally powered USB-hub. The ones I have simply connect the
5V to their power outputs, so they pass all of the current the power supply
can provide to the USB-devices. I even saw some (older) PCs that has
connected their 5V power directly to the USB. (Way beyond spec and risky of
course.)

petrus bitbyter

The gadget I mentioned is part of a bigger project. I mentioned it
separately only to simplify conversation.

-Can I just short the D+ pin from input to output ports
-Then short the D- pin from input to output ports
-Provide a separate 5V VBUS+ to output port
-Provide a common shorted GND.

Or is this a disaster eh?
Mike

.

Relevant Pages

  • Re: USB interface question.
    ... I'm envisioning a gadget that would take input from a USB port on a PC ... (or any USB host). ...
    (sci.electronics.design)
  • usb_insert_transfer panic with if_zyd
    ... When I use my ZyXEL G-220 Wireless USB Stick with the if_zyd driver, ... <ACPI PCI bus> on pcib0 ... device problem, disabling port 1 ... <Ethernet over FireWire> on firewire0 ...
    (freebsd-current)
  • 2.6.10-rc1 & ahci & IHC6R & 925X & raid1
    ... usb modules for console, usb keyboard, network and starting a shell. ... ACPI: PM-Timer IO Port: 0x808 ... PCI: PCI BIOS revision 2.10 entry at 0xfb768, ... usbcore: registered new driver hub ...
    (Linux-Kernel)
  • usb does not work on vias smp mainboard
    ... I installed kernel 2.4.21 on an via's mainboard, it seems that the usb ... number of MP IRQ sources: ... PCI Interrupt Link ... Port indicators are not supported ...
    (Linux-Kernel)
  • Re: sata_nv times out for BD-ROM iHOS104-08
    ... generic IDE driver loaded? ... ACPI: PM-Timer IO Port: 0x4008 ... CPU: Physical Processor ID: 0 ... USB 2.0 'Enhanced' Host Controller Driver ...
    (Linux-Kernel)