Yes. Cut the trace and it should work they way you want. But, don't expect any RMA support.
Gerald On Fri, Sep 27, 2013 at 11:09 AM, TB <[email protected]> wrote: > Gerald, > > Thank you for the reply. > > A hypothetical thought-experiment question... if the trace that sends > USB_DC to Pin 12 of the TPS65217C is absent yet still goes to the processor > (P15) would that disable the USB 5V sense of the TPS65217C yet still allow > the processor to recognized the USB when powered up? Thought experiment > only!! > > > > On Friday, September 27, 2013 11:20:46 AM UTC-4, Gerald wrote: > >> We have no instructions on how to break the board.The TPS65217C >> is designed to power the board from either of these sources, whichever one >> come first. If 5V is connected it switches to 5VDC when connected. >> >> One way to do what you want is to remove the power connection in your >> cable, cut the wire. However, if you do that, the processor will not >> recognize the USB as being connected and will not enumerate. >> >> On power off, the TPS65217C clears all the registers, so any registers >> that are set, will be reset on power up. >> >> Gerald >> >> >> On Fri, Sep 27, 2013 at 10:14 AM, TB <[email protected]> wrote: >> >>> >>> Hi, >>> >>> I need to disable the BBB from booting when usb is connected to the PC. >>> I have an external supply that powers the BBB as well as other things. I >>> would like the configuration such that even if a user connects to the BBB >>> via USB it will not boot until the 5V main power supply is turned on. >>> >>> Looking at the schematics and SRM I know that the TPS65217C senses the >>> USB 5V on its pin 12 and that there is some registers that control how >>> the TPS65217C responds to different signals and these registers are written >>> to via I2C. i just don't know how to do that. The following thread talks >>> about some commands that can be added to uEnv.txt to write to the >>> TPS65217C. I just wish there was more detail on how to do this. >>> >>> https://groups.google.com/**forum/#!searchin/beagleboard/** >>> USB$20power/beagleboard/**yNjXHmb1WnA/nlBoqnetbgcJ<https://groups.google.com/forum/#!searchin/beagleboard/USB$20power/beagleboard/yNjXHmb1WnA/nlBoqnetbgcJ> >>> >>> Are there easy instructions to modify the registers on the TPS65217C to >>> disable USB powerup? >>> >>> hardware: BBB A5C >>> OS: R. Nelsons' Ubuntu 13.04 (works great!) >>> >>> Thanks >>> >>> T. >>> >>> -- >>> 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...@**googlegroups.com. >>> >>> For more options, visit >>> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> >>> . >>> >> >> -- > 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/groups/opt_out. > -- 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/groups/opt_out.
