At Sat, 30 Mar 2019 15:04:27 -0700 (PDT) [email protected] wrote:
> > > Thanks for prompt reply. > > I am using edimax EW 7811UN WiFi adapter. I am powering the device by > external power adapter rated 5v 2A. Per my information this should be > sufficient for any USB peripheral device. I thought only mini USB port is > limited to 500mA. Are both the USB ports limited to 500mA? USB ports are rated for 500ma MAX. That is the *standard* for USB. When you power the 'Bone from its mini USB port you are only able to provide it with 500ma *total*, so its type-A Host port will have something *LESS* than 500ma available (500ma less what the BBB itself uses). It is my understanding, that *UNLIKE* the Raspberry Pi, that to get the full 500ma on the host port, you need to power the 'Bone from its Coax DC power jack, which can take in the full 1-2A available from the power supply. The Raspberry Pi's Micro-B "USB" connection is not really a USB port -- it is only a power connection and you can shove 1.5 or so amps in that way. This is not the case for the BBB's. Yes, there are power supplies with "USB" connections that are rated more than 500ma, but that is only meaningfull *if the device you are plugging it into is specificly "violating" the USB standard* and generally that is only going to be devices that are not really USB devices, but are just using the USB port as a power / charging connector, and not as a standard data connection. (Many smart phones "dual purpose" their USB port as a data connection *and* a charge port.) A USB WiFi adapter should not be expecting more than 500ma from the USB port. NO USB POWERED DEVICE SHOULD EXPECT TO GET MORE THAN 500MA FROM THE USB PORT. Any USB connected device that needs more power, will have its own power supply (that is why printers, for example, have power cords, as to many USB connected external disk drives, CD/DVD/BluRay readers/writers, etc.) [There are the "exceptions" I mentioned above, but those are obviously special cases.] > > Would really appreciate any help. > -- Robert Heller -- 978-544-6933 Deepwoods Software -- Custom Software Services http://www.deepsoft.com/ -- Linux Administration Services [email protected] -- Webhosting Services -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/20190331135232.8238D26C0010%40sharky3.deepsoft.com. For more options, visit https://groups.google.com/d/optout.
