Defective touch screen?

I purchased one of these cheap, no name, no part number, boards off ebay., and am using the Adafruit library.

It seemed to work well with a test sketch but when I designed my own layout I found that areas defined to receive clicks on one part of the screen gets clicked randomly and repeatedly. Any control I put in this area was affected but if I moved the control to another part of the screen it worked fine. I also inverted the screen rotation and the problem moved to the other side meaning it must be a hardware issue.

Is this a common problem with touch screens? Is there some code to filter out false clicks that I'm not aware of? I just wanted to be sure before sending it back for replacement. Thanks

You have a regular Blue 2.8" Mcufriend Shield. The Touch should work fine but is a bit more reliable if you alter NUMSAMPLES to 3 in the TouchScreen.cpp library file.

Of course, if your screen has got a cracked glass you will NEVER get a reliable Touch.

The 2.4" and 2.8" screens are quite robust. In my experience, the 3.5" screens seldom make it through China Post. This is down to inadequate packaging rather than the Mail Carrier.


Thanks for the information. There are no cracks and the touch seems to be reliable everywhere else on the screen. I’ll make the change in the library and try again.

I made the change to the library you suggested and I believe the touch is more reliable. Of course it didn't solve the problem of getting phantom clicks on that one section of the screen since it has to be a hardware issue. Thanks for the pointer though.