Graham -- I figured that's probably what USB1_EN is for. Most of the USB power switches have an enable pin (the 4- or 5-legged ICs), but a couple of them don't (the 3-legged ICs). Thanks again for the advice!
-- Will On Friday, November 17, 2017 at 12:18:27 PM UTC-7, Graham wrote: > > If your USB power switch requires an On/Off enable control input, that is > what pin P1-03 is for. > --- Graham > > > > On Friday, November 17, 2017 at 12:11:59 PM UTC-6, wi...@geomonkey.com > wrote: >> >> Graham -- >> >> Thanks for the advice! That totally makes sense. I now intend to try this >> configuration to get the added USB1 working in host mode (e.g., to control >> a Sony camera using the gphoto2 library): >> >> >> <https://lh3.googleusercontent.com/-lu0aOUP8tbc/Wg8Z3vezBxI/AAAAAAAAAUQ/ud2QXK4zW9gwIhrqVif5ChtTqCcqjDicQCLcBGAs/s1600/PocketBeagle_microUSB_3.png> >> >> These USB power switch ICs (e.g., Diodes Incorporated AP2822AKATR-G1, >> Richtek RT9711CGB, >> Richtek RT9742JNGV) limit current, prevent reverse current, etc., and >> cost less than a dollar. I'll report back about whether this ends up >> working okay. >> >> -- Will >> >> >> On Thursday, November 16, 2017 at 5:10:48 PM UTC-7, Graham wrote: >>> >>> Your first connection does not work, because you are trying to power the >>> USB1 from the USB_VIN, but since the is no power going into USB_VIN on >>> USB-0, there is no power to come out USB-1. >>> This only works when the board is powered from USB-0 >>> The schematic does not tell you, but USB_VIN, USB0_VIN and USB1_VIN are >>> all connected together. >>> >>> VIN is a totally separate power supply input >>> >>> Since you are powering the board from VIN (P1-01) you need to hook the >>> 5V line on your Micro-USB board to P1-01 and P1-05. >>> >>> In this case, it will work, although you have no current limit >>> protection from a short on the 5V line in a downstream USB device, which is >>> required by the USB spec. >>> So, only plug in USB devices and cables you trust. >>> >>> I would not power the USB-5V-VBUS from the SYS-VOUT, because SYS-VOUT is >>> limited to 0.2 A or so, and many USB devices draw more current than this >>> (USB-2 devices are allowed to draw up to 0.9 A) >>> >>> --- Graham >>> >>> == >>> >>> On Thursday, November 16, 2017 at 5:11:52 PM UTC-6, wi...@geomonkey.com >>> wrote: >>>> >>>> I, too, am wondering about the best way to provide power to the board >>>> and to a device connected to USB1 as host. Here is how I learned to hook >>>> up >>>> a micro-b breakout to USB1 and also how I intend to provide power to the >>>> board. The problem is that there is no measured voltage at USB1: >>>> >>>> >>>> <https://lh3.googleusercontent.com/-XyHjxbobnnY/Wg3xGzyvNcI/AAAAAAAAATo/u1ufBwtum9c4KA6T6zjnu38x4cwwQ3TNQCLcBGAs/s1600/PocketBeagle_microUSB_1.png> >>>> >>>> I was wondering if I could just power the USB1 device from P1_24 SYS >>>> VOUT (which does have power when board is supplied by P1_01 SYS VIN) like >>>> this: >>>> >>>> >>>> <https://lh3.googleusercontent.com/-l4RYr7WmaGU/Wg3xqYECajI/AAAAAAAAATw/ipK3CZmhG18cieC-bnMLV04PfPBl_hRRACLcBGAs/s1600/PocketBeagle_microUSB_2.png> >>>> Would it be harmful to do it this way? Are there better ways to >>>> accomplish this? Thanks! >>>> >>>> -- Will Bain >>>> >>>> >>>> On Sunday, November 5, 2017 at 6:59:39 PM UTC-7, Graham wrote: >>>>> >>>>> Further research, looking at the Eagle board and schematic files for >>>>> the PB, it appears that USB0.VIN and USB1.VIN are both directly connected >>>>> to VIN.USB >>>>> Which explains why I had no power on my USB1 host port when connected >>>>> like the Fritzing diagram, since I am powering from VIN currently. >>>>> >>>>> So the question becomes,,, >>>>> What is the best way to power USB1 VBUS as a host if I don't know in >>>>> advance whether the customer application will run from VIN or VIN.USB? >>>>> >>>>> --- Graham >>>>> >>>>> == >>>>> >>>>> On Sunday, November 5, 2017 at 6:58:06 PM UTC-6, Graham wrote: >>>>>> >>>>>> I note that there is a PocketBeagle pin P1-7 named USB1-VIN. >>>>>> >>>>>> I don't find any connection on the PB schematic, other than to P1-7. >>>>>> >>>>>> It was connected externally in all of the USB1 host discussions and >>>>>> Fritzing diagrams. >>>>>> >>>>>> The name would imply that it is a way to deliver power to the board >>>>>> when USB1 has an external 5 Volt power source. >>>>>> >>>>>> I guess the basic question is whether this needs to be used/connected >>>>>> when USB1 is functioning as a host. >>>>>> >>>>>> --- Graham >>>>>> >>>>>> == >>>>>> >>>>> -- 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 beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/fe7df138-d06b-4aba-b633-fc1b94ea8b32%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
