[App_rpt-users] Ras Pi 2 doesn't like xenon flashes???

[David McGough]

Hi Mike & Everyone,

My initial questions (and alarm) were if the RPi2 might be excessively 
sensitive to external EMI---something like that can be really hard to deal 
with around high RF environments.

But, after reading more threads, it appears this issue is truly light
sensitivity in one of the switching PS chips (U16), due to how it's
encapsulated (or lack thereof!) in plastic. Adding a small light shield
apparently fixes this issue, based on what other testers say.

I don't yet have a RPi2, so I can't test.


73, David KB4FXC



On Sun, 8 Feb 2015 mike at midnighteng.com wrote:

> 
> Not having tested it specifically, I would find it plausible for a xenon
> flash in very close proximity to a micro-controller create a problem but
> only in this way...
> 
> RFI/EMP burst during flash, a pulse being picked-up on circuits. If not
> RFI changing something directly in ram, EMP could just put a extra binary
> digit in a stream of data or a extra pulse in the clock line. The later in
> the clock line being most probable for a lock-up. Not from the flash of
> light. The broad pulse comes from it's ballast. The wires attached to it
> and the bulb act as a antenna.
> 
> If it is a problem with a strobe light, I'll bet you could get a similar
> action from a close proximity GSM cell phone during certain phone actions.
> And I would also bet you could find that the Pi would not be the only type
> of micro-controller than can be affected by this type of thing.
> 
> Not to worry, Shield your Pi like you should be doing in any case and
> provide sinks for RFI on all lines in and out of the shielded area. This
> would be normal protection in a RF hostile environment. Radio 101 - It
> should never be a real issue in a properly constructed repeater.
> 
> ...mike/kb8jnm
> 
> >
> >
> > Hi Everyone,
> >
> > I just saw this thread in another newsgroup. Basically, they're saying the
> > Pi2 will hang/crash if subjected to a close xenon camera flash discharge!
> >
> > Weird! Can anyone confirm if this is true?  ...If they're sensitive to a
> > flash, they might be sensitive to RF as well. Perhaps an EMP issue?
> >
> > Here is a link to the thread:
> > http://www.raspberrypi.org/forums/viewtopic.php?f=28&t=99042
> >
> > Again, I have NOT personally confirmed this report, but am sitting here
> > looking puzzled!
> >
> >
> > 73, David KB4FXC
> >
> >
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