You need to make sure that there is an earth ground on your power supply. The case of the USB connectors go to the common point ground, which is a zero ohm resistor by default to the DC ground input.
Gerald On Tue, Dec 23, 2014 at 5:40 AM, <lee.s...@bibby-scientific.com> wrote: > Thanks for the prompt response Gerald. > > The beagle has been designed into a system which is in a plastic and metal > enclosure. The only I/O it has to the outside (other than touchscreen) is > 2 USB connections. > > These connections are what are prone to the 4kv ESD. A discharge on the > shell of the USB connector causes the micro to reset. This occurs even > though ESD suppression has been designed in at the USB connectors. > > The micro seems particularly prone to this phenomenon. ESD is an awkward > problem to solve, there isn't one solution to fit all and things such as > enclosure design can have an influence... > > On Monday, 22 December 2014 19:42:37 UTC, Gerald wrote: >> >> I am not sure what was used, other than putting it in a box or adding ESD >> protection devices on every point on the board likely to be touched by a >> person. >> >> The certification was done by a lab. You are welcome to download the full >> report from the WIKI. >> >> http://www.elinux.org/Beagleboard:BeagleBoneBlack >> >> Gerald >> >> >> On Mon, Dec 22, 2014 at 7:57 AM, <lee....@bibby-scientific.com> wrote: >> >>> Hi Guys, I am seeing the same issue as Richard above. Was a solution >>> ever found for this ESD reset issue? >>> >>> In the past I have had some success on solving this issue on other >>> micros by adding some capacitance on the micro's reset line to prevent the >>> reset I/P bouncing when the ESD takes place, however looking at the BBB >>> schematics, this is already included in the form of C24 being 1uF. >>> >>> Richard, did you find a solution to this? >>> >>> Gerald, I assume this family of processors must be used in many >>> commercial products. Do you have an idea of what solutions were used to >>> overcome this? >>> >>> Many thanks in advance. >>> Lee. >>> >>> On Friday, 1 August 2014 18:57:39 UTC+1, Gerald wrote: >>>> >>>> CE testing that was does not cover ESD testing. This board has never >>>> been tested for ESD. >>>> >>>> Gerald >>>> >>>> >>>> >>>> On Fri, Aug 1, 2014 at 12:21 PM, Richard Ketcham <rich.k...@gmail.com> >>>> wrote: >>>> >>>>> Hello, >>>>> >>>>> I'm interested in CE testing a device which includes the BBB. In order >>>>> to determine if the device will pass, I've been shocking it with an ESD >>>>> gun >>>>> (both contact and discharge). I have been running into an issue where >>>>> when >>>>> I shock the ground plane with a 4kV contact discharge, the BBB Ethernet >>>>> becomes unresponsive and does not recover until I cycle the power. I've >>>>> tried this test with only the BBB and it reacts the same way. I see >>>>> there's >>>>> a CE certification which says it passes 4kV contact discharge, but I've >>>>> been unable to replicate it. >>>>> >>>>> >>>>> Are there caveats to the CE certification which the BBB has relating >>>>> to ESD testing? >>>>> Is this a self certification? >>>>> Do you have any suggestions on how mitigate this problem? >>>>> >>>>> I will appreciate any information you can provide on this problem. >>>>> Thanks, >>>>> Rich >>>>> >>>>> -- >>>>> 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/d/optout. >>>>> >>>> >>>> -- >>> 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/d/optout. >>> >> >> >> >> -- >> Gerald >> >> ger...@beagleboard.org >> http://beagleboard.org/ >> http://circuitco.com/support/ >> > -- > 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/ http://circuitco.com/support/ -- 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.
