I know it is a bit confusing. If you do, it will blow up the processor. It is a function of the processor.
I suggest you read the datasheet on the processor as it relates to power sequencing. http://www.ti.com/product/AM3358/technicaldocuments Until the 3.3V rail comes up, nothing on your board can be powered up.Even if it is from the same source. Again, it is a matter of power sequencing. All the rails must come up and power down in a particular sequence. Violate that sequence, then you are asking for trouble. Power your circuit off of the VDD_3V3B rail or use the VDD_3V3 rail to enable the power on any external circuitry that connects to a pin on the processor. Gerald On Mon, Jul 27, 2015 at 2:18 AM, <yoyovaug...@gmail.com> wrote: > > Alright, I know that there are a lot of discussions on here about this > topic, and I have read through them, but I am still a bit confused about > this line in the manual: > 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. > > I am working on a project that will involve me using multiple sensors with > the BBB that are powered from another source. One of those sensors is a GPS > that spits out data as long as it is powered, but the others only send data > after they have received a request. Here are my questions: > > 1. Based on that statement, it is my understanding that if the GPS I'm > using is powered and the BBB is not, then the BBB will be damaged. Is this > accurate? > 2. What if the board and all the sensors are powered from the same source > controlled by a single switch? Will this damage the board when I flip on > the switch? > 3. What if I power all the sensors from the board itself so that it is > impossible for them to receive power before the board does? Will this > damage the board? > > -- > 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/d/optout. > -- Gerald ger...@beagleboard.org http://beagleboard.org/ -- 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/d/optout.
