On Mon, Nov 9, 2015 at 3:46 PM, William Hermans <[email protected]> wrote: >> It also depends on the usb host/hub, on power up we get 100mA, and in >> u-boot we request "1.3A" over usb... If we actually get that "1.3A" we >> can do a lot, but most often then not we only get 500mA's.. >> >> I don't have the exact numbers at my desk, but i thinking a booting >> v3.8.x needs a peak around 350mA's for the core & mmc.. > > > So that ust be some "special" USB power adapter, that is not plugged into a > PC per se. I've been powering over USB 3.0 port to the RevC. Which is from a > "high end" laptop, which should be able to give the board at least 800ma. I > do not recall if I had problems with that setup using ethernet + CAN. But > the one where we have the logic supply serial / can cape connected to. Used > a 1A wall-wart to USB adapter. It worked fine for a little while, then start > exhibiting strange behavior at system up. So on a hunch, wulf and I just > replaced that power supply with a 1A barrel jack supply, and the problem > went away . . . > > I'm still confused how you can get more than 500ma over USB2.0 though . . . > as the spec says 500ma max.
It's in the battery charging spec.. So for most devices users plug this in, it doesn't work.. Regards, -- Robert Nelson https://rcn-ee.com/ -- 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]. For more options, visit https://groups.google.com/d/optout.
