Main Site Documentation

CP7 touch not working (difficult environment)

#1

I have a large fish tank and a lot of T5 lights (https://www.google.si/search?q=t5&aq=f&um=1&ie=UTF-8&hl=sl&tbm=isch&source=og&sa=N&tab=wi&ei=pJKXUZ_mNMXcswb9yYCIBQ&biw=1920&bih=955&sei=ppKXUf_7J8rUsgbiwoDADw#um=1&hl=sl&tbm=isch&sa=1&q=t5+lighting&oq=t5+light&gs_l=img.3.0.0i19l10.2319.3163.0.4544.6.3.0.3.3.0.80.218.3.3.0...0.0...1c.1.14.img.7YQuaY9riFo&bav=on.2,or.r_qf.&bvm=bv.46751780,d.Yms&fp=4f38f376c78df4f3&biw=1920&bih=955)
I just mount my CP7 and Cobra II on a closet where the aquarium is.
I figure it out, that when the light is on, the touch screen acts weird. It triggers all events randomly.
I have a light on the other side of the closet, so the light and CP7 are 10cm apart.

I just want you to know, be careful.
And secondly:
Does anybody know what could I do. I have several holes in my closet, so choosing another place is not a suitable solution. Should I place some mirror, metal … between light and CP7. Does anybody have any idea?

#2

What is happening? You are losing the image?

#3

triggers touch events?

current draw of lights causing voltage drop and loss of regulation?

#4

The touch screen is capacitive, so I wonder if there is so much noise coming causing a false detection.

#5

time for a tin foil hat for the cp7 then :slight_smile:

  • note, that may not work and was not a serious suggestion. Just sayin.
#6

@ Makla -

Out of my knowledge base but I did find this link. (One of many)

I only mention this because I have experienced this problem on some computer equipment at some customers (Commercial printers). Transformer noise is not limited to only T5. Many older transformers do the very same thing…

Just a thought…

#7

Mostly the problem is that touch event are not fired. But from time to time, the events are fired but nobody touched the screen. I also figure it out, that the system became unresponsiveness.
It is certainly lights, because when they are switched off, everything works as expected. Also when I moved CP7 5-8cm away from the closet, everything works as expected.

#8

Disclaimer: I’m not an Electrical Engineer… Following links may have helpful info (fluorescent lights EMF can definitely affect touch detection):

http://www.optoelectronics-electronicspecifier.com/Displays/Avoiding-EMI-in-capacitive-touch-screens.asp

http://www.lrc.rpi.edu/programs/NLPIP/lightinganswers/pdf/view/LAEMI.pdf

http://www.edn.com/design/sensors/4411529/3/Aggressively-combat-noise-in-capacitive-touch-applications

#9

When I used to work on Jukeboxes we used to have no end of trouble with the touchscreens. Any interferance from nearby electronics or metal can cause the touchscreen to detect an event or completely miss someones touch as the charge wouldnt be sufficient against the background…

Three possible solutions were

  1. Move the touchscreen away from other electrical devices, you need to ensure a decent gap between the two.

  2. Find the device thats causing the problem and create a screen between the two objects. Normally using something slightly Lead based

  3. Check the screen isnt too close to anything metal, I think this primarily effects the capacitive types of screens

HTH

Paul

#10

This (http://www.abk.si/izdelki/96.jpg) solve my problem. :slight_smile:

#11

Could you describe what you did?
I’m having similar problems

#12

Made a tin foil hat for the CP7.

It’s a classic interference issue, I’d suggest you start by building a shield for around the connectors, then go wider as you need until you get decent results. It really is a harsh noisy electrical environment around Fluoro lights so your installation will likely need specific shielding for your situation, and trial and error will be the best way to deal with it - unless you have good instruments that can help here, whatever they are - but I’d expect that if you do you probably wouldn’t have been asking for our advice.

#13

@ Makla - lol… im sorry you were experiencing troubles… but the solution is HILARIOUS! and it actually worked? hahahahaha, nice.