Gerald, Thanks, another power supply does work. 5v nominal, 5.2v measured, 2.6 amps.
Although this workaround will help keep my project going, I would suggest that you pursue this as a fault of the BBB. There are behaviors documented here, and not mentioned that indicate a sensitivity to minor perturbations in power and ground that will cause problems for BBB users and those who must support the BBB. When my BBB is running with both the "faulty" power supply, and the PC USB power, and the power supply is removed, the BBB shuts down. When I turn on or off a device that is connected to the BBB (a Sherline 8760 stepper driver connected through a Zylotex DB25 cape), the BBB powers down. The "faulty" power supply was procured from a reputable equipment dealer for the purpose of running the BBB, and is in spec. There is a problem with the BBB. It should tolerate variations in its electrical environment. As attractive as the BBB is, developers cannot wrap it in photoisolators, chokes, and paranoia. If there is a problem with some 1 amp power supplies not having enough power moment to moment, perhaps you should specify a 2 amp power supply. Maybe you should recommend an additional capacitor be place across the power supply. Thanks again for your quick and accurate help, and good luck with your efforts to support the BBB. --Justin On Sunday, November 9, 2014 10:31:53 AM UTC-5, Gerald wrote: > > We have seen this before. I suggest that you try another power supply. > While current is important, so it the rise time of the power supply. Try > getting one with higher current rating to see if the rise time is faster. > Or just try another power supply. > > Gerald > > > On Sun, Nov 9, 2014 at 12:18 AM, Justin <[email protected] <javascript:> > > wrote: > >> I've been using my BBB RevC just fine with it connected to my computer's >> USB Host port. I finally got the bits I needed for standalone -- HDMI >> cable, USB hub, power supply, etc. >> >> If I plug the power in to the otherwise unconnected BBB, the power light >> lights, the four status lights light, then all five shut off. >> >> If I plug the USB from the PC in to the otherwise unconnected BBB, it >> boots right up, normally. If I then plug in the power, there is no change. >> If I then unplug the USB, no change. It runs on the power dongle! >> >> If I plug the USB from the PC in to the otherwise unconnected BBB, it >> boots right up, normally. If I then plug in the power, there is no change. >> If I then unplug the power, the BBB shuts down, even though the USB is >> still connected. >> >> The power is from a wall wart -- 5v nominal, 5.3v measured, 1 amp nominal. >> >> There is no SD card installed. I bought the BBB direct from Atoms Ind. a >> couple weeks ago, and have not (to my knowledge) changed anything. >> >> Any suggestions? >> >> -- >> 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] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Gerald > > [email protected] <javascript:> > http://beagleboard.org/ > http://circuitco.com/support/ > -- 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.
