On Fri, Nov 30, 2012 at 3:06 AM, Arne Pagel <a...@pagelnet.de> wrote: > On 29.11.2012 02:40, Xiaofan Chen wrote: >> >> What if you change the 500mA to something like 0mA (or something >> below 100mA) since your device is Self-Powered? Does your >> device really consume 500mA from the bus? > > My device can definitely consume more then 100mA, 500mA are a a maximum > setting. > I think there was some possibility in some USB spec that you also can > provide just 100mA as host. > > But logically you shouldn't consume any current when you say you are self > powered. > So you are right, my setting here isn't consistent here, I will change it. > But if this really the reason for the behavior I have here I will send you > some cookies. > > What I know from some USB Hardware is, when they have a active current shout > down, this is usually not that accurate. > I know USB Protection chips which just detecting over currents between 550 > and ~1A. > > If this would be really accurate, I assume no (older) USB HDD would work, > many of them violated the max current limitation. > If you are interested, two examples: > http://www.onsemi.com/pub/Collateral/NCP362-D.PDF > http://www.ti.com/lit/ds/symlink/lm3544.pdf > Not sure about the PC world and what is really used there. > > Anyway, > here is the output from USBView, with the Configuration Descriptor Flag on. > (Other devices show something there) > > Device Descriptor: > bcdUSB: 0x0110 > bDeviceClass: 0xFF > bDeviceSubClass: 0x00 > bDeviceProtocol: 0x00 > bMaxPacketSize0: 0x40 (64) > idVendor: 0x16D0 > idProduct: 0x05BE > bcdDevice: 0x0100 > iManufacturer: 0x01 > iProduct: 0x02 > iSerialNumber: 0x03 > bNumConfigurations: 0x01 > > ConnectionStatus: DeviceConnected > Current Config Value: 0x01 > Device Bus Speed: Full > Device Address: 0x08 > Open Pipes: 2 > > Endpoint Descriptor: > bEndpointAddress: 0x81 IN > Transfer Type: Bulk > wMaxPacketSize: 0x0040 (64) > bInterval: 0x00 > > Endpoint Descriptor: > bEndpointAddress: 0x01 OUT > Transfer Type: Bulk > wMaxPacketSize: 0x0040 (64) > bInterval: 0x00
You forget to CC the list. Anyway, the USBView output seems normal and at least your device enumerated properly. -- Xiaofan ------------------------------------------------------------------------------ Keep yourself connected to Go Parallel: TUNE You got it built. Now make it sing. Tune shows you how. http://goparallel.sourceforge.net _______________________________________________ libusbx-devel mailing list libusbx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libusbx-devel
