LVGL demo not working with nRF9160DK

[Christoffer Brask]

Hi,

I'm trying to use the adafruit_2_8_tft_touch_v2 shield on a nRF9160DK with the LVGL demo but it fails.

Project is unmodified and build on nRF Connect SDK 2.6.1 and 2.7.

Project works on nRF52840DK but not on nRF9160DK.

Backlight is turned on but nothing is drawn.

If I disable input so touch is disabled with CONFIG_INPUT=n, I see the hello world label and the counter label but this only confirms that screen is working.

When CONFIG_INPUT is enabled, CONFIG_I2C is also enabled with NRF_TWIM not sure whether the problem is related to I2C somehow?

One last thing, I have tried changing VDD IO to 3.3V without it changing anything

[Michal]

Hello,

Which pins do you use on nRF9160 DK for that?

Best regards,

Michal

[Christoffer Brask]

Touch panel controller is on i2c2 so SDA P0.30 and SCL P0.31

Display is on spi3 so SCK P0.13, MISO P0.12, MOSI P0.11

[Michal]

On the nRF9160 DK SPI3 pins by default are connected to the external flash:
https://docs.nordicsemi.com/bundle/ug_nrf9160_dk/page/UG/nrf91_DK/hw_description/if_connector.html

https://docs.nordicsemi.com/bundle/ug_nrf9160_dk/page/UG/nrf91_DK/hw_description/external_memory.html

Please try to use other pins than the ones mentioned on the first page (or change the solder bridge configuration physically).

Best regards,

Michal

[Christoffer Brask]

Not sure how this would help? I already wrote that the display works if I disable touch with CONFIG_INPUT hence the SPI works. The external flash is not used in the demo project.

[Michal]

Sorry, I misunderstood a bit. Have you checked the data lines with a logic analyzer?