Thank you for the confirmation. I just wanted to make sure my understanding of how it was working is correct.
Believe me, I understand completely regarding any modification I make are my responsibility. That's the beauty of the BBB, you learn alot about software and hardware and a boo-boo only cost you $45. I can live with that. In my engineering career I have blown up things a lot more expensive, ha! thanks again On Friday, September 27, 2013 12:44:47 PM UTC-4, Gerald wrote: > > 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] <javascript:>>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] <javascript:>. >> 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.
