Arduino Due 7" TFT LCD touch screen problems

Official Hardware Mega Due
1

Hello guys,

I am working on a project with 7" TFT LCD using UTFT and UTouch libraries. LCD works well now although I initially had problems with inverted image but I fixed that. Now I want to make a touch screen interface using UTouch library. Unfortunately I have serious problems reading the coordinates from touchscreen. No matter where on screen I press I always get the same coordinates which are X799 and Y0. I tried running the calibration program but to no avail. No matter which part of the screen I press during calibration I get following results;

CAL_X 0x03FFCFFFUL
CAL_Y 0x03FFCFFFUL
CAL_S 0x001DF31FUL

After I fixed UTouchCD.h with the upper calibration I tried running quick draw and I am still getting only X799, Y0 readings no matter which part of touchscreen is touched. If I run calibration program again I get the same calibration results. Here are my pin definitions but I am certain the problem is not originating from here.

UTFT myGLCD(CTE50,25,26,27,28);

UTouch  myTouch( 6, 5, 4, 3, 2);

Touch screen driver IC on my LCD module is XPT2046, I checked online if there are any known problems with this chip but there seems to be nothing obvious.

Here is the hardware I am using

Guy from this topic suffered a similar problem but nothing mentioned there helped me at all.
http://forum.arduino.cc/index.php?topic=152471.0

I would really appreciate all the help with this situation.

Thanks,
Filip

2

First of all, you're not using a CTE display. Check your pinouts to make sure they are compatible.
Next: if the display is compatible, use the CTE70 display not a CTE50.
The numbers after the display coincide with the SPI port. Double check these to make sure they are correct.
Finally, make sure that your touchscreen pens are in the same place as on the CTE board.
Any discrepancy can cause problems.
Make sure that you set up the calibration screen correctly with the proper CTE screen size.

Hope this helps.

Sam.