ESP8266 Community Forum

The touch screen and the TFT share the same SPI bus. This means they need separate CS control.
Your code sets the touch CS but perhaps the TFT CS which isn't explicitly disabled is glitching since it might be receiving the touch SPI data.

Hi NailBuster...

OK! I figured it out, thanks to your comment.

It turns out that I'm an idiot. This is because I assumed that all these 2.4" SPI TFT units have a touchscreen on the front of the display. In fact, they do not all have a touchscreen! I didn't even think to look at it.

When you said "is it possible your screens aren't using an XPT2046 controller?", that prompted me to gently pull the TFT module away from the PCB to look for the touch controller IC to verify the number, and discovered that there wasn't any IC at all. Then I realized "Duh! There's not even a touchscreen layer on the front of this TFT display!"


I hope this thread helps someone save a week of their life.

Thanks for your help,and thanks to everyone else who replied.

Hi Everyone!

I received some touchscreen-equipped screens. Wow!

YAY! Touch functionality works great with NailBuster's circuit and any of the touch code when it is connected through an Adafruit Huzzah Feather (similar pin map to a NodeMCU), but when I connect the display to a raw ESP8266-12E or -12F using the same pins (as converted through a pin map, and the code is adjusted), the touch functionality does not work.

Does anyone have any idea why that would make a difference? Do I need a pull-up or pull-down somewhere on the raw ESP that is there on the NodeMCU or Feather?

I plan to use a raw ESP8266-12F for my product, instead of a NodeMCU or Feather.

Thank you all so much!

Hi
Like yourself I have wasted many hours fighting with the touch functionality, 4 "touch" screens, several flavours of ESP8266 and hundred of lines of code. I just assumed an item advertised as a touch screen was a touch screen. Anyway thanks for your post, but can you tell me where you sourced a proper display.
thanks
John