Issues getting basic display working on nrf5340/Zephyr

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I am just trying to display a button with some text… I see three buttons instead and text looks like garbage excpet on one button

What MCU/Processor/Board and compiler are you using?

Nrf5340 MCU, Custom board, RM69090 Display controller (QSPI), 320%360 AMOLED display. Zephyr RTOS with Nordic NCS (SDK) with built-in gcc tools)
NCS version: 1.5.1
LVGL version: ## v7.6.1 (06.10.2020)
Zephyr RTOS version: 2.4.99

What do you want to achieve?

Get a button displayed on the screen but i see three identical buttons

What have you tried so far?

Went through he documentation (pretty good), porting section, your git hub, zephyr’s (poor) VGVL documentation… code compiles and there are no errors/crashes… But the button shows up 3 times and text is surely not very clear. I don’t care for the button press getting recognized (yet) as I have not looked into integrating touch controller driver with lvgl yet. Just want to see a single button with text is all I am looking for right now. AS mentioned, I see multiple buttons when i am coding for just one (or so I think)

Code to reproduce

Add the relevant code snippets here.

The code block(s) should be between ```c and ``` tags:

/*You code here*/

void btn_event_cb(lv_obj_t * btn, lv_event_t event) {
    if(event == LV_EVENT_CLICKED) {

void set_button(void) {
	lv_obj_t * btn = lv_btn_create(lv_scr_act(), NULL);     /*Add a button to the current screen*/
	lv_obj_set_pos(btn, 10, 10);                            /*Set its position*/
	lv_obj_set_size(btn, 150, 100);                          /*Set its size*/
	lv_obj_set_event_cb(btn, btn_event_cb);                 /*Assign a callback to the button*/

	lv_obj_t * label = lv_label_create(btn, NULL);          /*Add a label to the button*/
	lv_label_set_text(label, "Button");                     /*Set the labels text*/

void main(void) {
//lots of hardware init stuff here

	/* Initialize the device */
	display_dev = device_get_binding(DISPLAY_DEV_NAME); //(CONFIG_LVGL_DISPLAY_DEV_NAME);
	if (!display_dev) {
		printk("Binding Display failed... will loop for ever");

	display_get_chipid(display_dev); //gets the chip id of the display controller)


Screenshot and/or video

If possible, add screenshots and/or videos about the current state.


Most probably it’s an issue in the disp_flush_cb in the display driver. E.g. when it copies the rendered image to the display and wants to move to the next line jumps fewer pixels. (e.g. counting bytes instead of pixels, or so)

If you can’t find the issue yourself, please copy the flush callback here (or a link to it).

I am looking at it right now… I had also missed calling lv_disp_flush_ready at the end of the flush function and i just fixed that… will update the ticket if i make progress(or not)

Thank you for the quick response

Turns out I expected way too much from my display vendor… the driver wasn’t configured correctly… once i did that and also adding lv_disp_flush_ready , I can see a single button i expected…

Now to increase the font size… I have searched the forum and as per this link I can not increase font size unless i use some another font… This is my first time dabbling with LVGL and hence any help will greatly be appreciated

I found ways to increase/decrease font sizes… this ticket can be closed.

Thank you

Dear sshenoy105,

I am working with a QSPI RM69090 from china, unfortunatly the datasheet shared only mention DualSPI implementation, how did you manage to implement QSPI, can you share with me your RM69090 datasheet if so ?

Thanks for your help

We moved away from RM69090 due vendor’s recommendation that they won’t be available in bulk. RM69090 does support QSPI (Note: nrf5340 QSPI will only work as a single wire QSPI as we will have to use custom instructions)… The datasheet i have doesn’t have anything specific to QSPI either… but we were able to bring up LVGL and draw a bunch of screens etc. on the display module

Thanks for your answer, I will keep digging,