We've designed a product which uses a BeagleBone Black with a resistive
touch screen. The BBB controls some external hardware which is designed to
generate large amounts of EMI. When gating is on, the hardware resonates
at around 200 kHz, most likely with large amounts of harmonics. When
On 7/2/2014 9:08 AM, henry.g.mcdon...@gmail.com wrote:
Is there a way to disable touchscreen sampling for a short time period when
the gate signal (generated by the BBB) is asserted?
Probably, but I'd try to fix the hardware first.
It sounds like the EMI itself isn't directly causing the
Use an interrupt maybe to tell SW to ignore? Might slow things down.
Is it really that simple? Is there just a port, or a named pipe, or some
shared memory location that you can write to to briefly disable the
touchscreen? I can imagine that it wouldn't be too difficult to shut down
a
Real solution is to fix the issue. You just asked how to trigger a shutdown
which was my answer. That would not be my solution.Shutting down
a touchscreen for x amount of ms will be tough to do..
Gerald
On Wed, Jul 2, 2014 at 2:38 PM, henry.g.mcdon...@gmail.com wrote:
Use an interrupt maybe
The power rails are solid, to our knowledge. The BBB has been powered from
different power supplies than the EMI generating hardware as well as a
battery. Our scope captures don't show anything definitive on the power
rails, but it is kind of clouded by the fact that the scope is affected by
Real solution is to fix the issue.
Agreed. The trouble is figuring out how to fix the solution. We could run
the BBB off of a battery, put it in a Faraday cage, and optically couple
the gate drive to the BBB, but then you couldn't get to the touchscreen.
The issue at hand is that the
