Problem using lvgl:

[Pablosanserr]

Hi,

I am using an nRF5340DK and an Adafruit 2.8" TFT Touch Shield to implement a touch keyboard on the board.

I am modifying the lvgl example provided by the sdk. The initial example worked fine. However, when I make changes to add the keyboard widget, it does not work. The original lvgl example works correctly, so I guess it's not a problem with the pin connection.

The keyboard is displayed on the screen, but touching it does nothing.

Also, when I touch the keyboard, I get the following error:

I am new to using screens on this type of board and using lvgl, so I don't know what could be wrong.

This is the current project. I attach it in case it could be useful.

lvgl_keyboard.zip

Useful information about the project:

- Using nRF5340DK and an Adafruit 2.8" TFT Touch Shield

- Using nRF Connect SDK v2.2.0.

- I have implemented the keyboard using this documentation

[haakonsh]

I suggest you start by enabling any relevant logging. At least for zephyr I2C driver, nrfx twim driver, and lvgl library. 

I also suggest you scope the I2C lines with a digital analyzer and see what happens before and after you touch the screen. 

[Pablosanserr]

Hi,

Thanks for the suggestion. Unfortunately the logs did not show me any relevant information about the problem.

However, I have found the problem. The lv_task_handler() function must be called continuously so that lvgl can react to events.

Adding an infinite loop at the end of main solved my problem. The keyboard works correctly.

while(1){
	lv_task_handler();
	k_sleep(K_MSEC(5));
}