Yes you can do that Use the 3.3V to enable the regulators. Gerald
On Thu, Mar 6, 2014 at 9:03 AM, Matthew Witherwax <ablec...@gmail.com>wrote: > Thanks Gerald. That is exactly the response I was expecting and exactly > the feeling I had. Never really like playing Russian roulette myself. Do > you see any issue with powering the sensors via a voltage regulator like > http://www.pololu.com/product/2098 that can be turned on via a pin on the > BBB once it is up and running? > > > On Thu, Mar 6, 2014 at 8:58 AM, Gerald Coley <ger...@beagleboard.org>wrote: > >> I put that in there for a reason. It may not happen all the time, but >> eventually you could blow up the processor. >> >> Gerald >> >> >> On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax <ablec...@gmail.com>wrote: >> >>> As part of the Control of Mobile Robotics class offered through >>> Cousera, the students are building robots based around the BeagleBone >>> Black. The robot has 5 infrared distance sensors and 2 reflectance sensors >>> used for odometry. These sensors are connected via voltage dividers to >>> pins 33, 35, 36, 37, 38, 39, and 49 of P9, and are powered from the same >>> power supply used to power the BeagleBone Black. The System Manual has a >>> rather explicit warning: >>> >>> NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED TO >>> THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY. >>> NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH. >>> >>> My concern is the current arrangement would allow the sensors to begin >>> driving the pins before the SYS_RESET line goes high; however, I am a >>> software guy just starting down the hardware path. Thus far many in the >>> class have been using the robot without issue. Is my concern invalid? >>> >>> Thank you for your time. >>> >>> -- >>> 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. >>> >>> 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 a topic in the >> Google Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/_5Puwswy-RQ/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> beagleboard+unsubscr...@googlegroups.com. >> >> 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 beagleboard+unsubscr...@googlegroups.com. > 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
