Button create stops code

Micropython
1

Hello,

Trying to run code below and looks like code stopes just after run line btn = lv.btn(scr) and I don’t see any picture. What might be wrong? How to solve this problem?

import sys
import lvgl as lv
try: 
    lv.init()
    print("start")
    scr = lv.obj()
    print("1")
    btn = lv.btn(scr)
    print("2")
    btn.align(lv.scr_act(), lv.ALIGN.CENTER, 0, 0)
    label = lv.label(btn)
    label.set_text("Button")
    lv.scr_load(scr)
    print("end")
except:
    print("Unexpected error:", sys.exc_info()[0])
    raise

Output:

start
1

UPD

I have updated code with display driver as recommended:

import sys
import time
import lvgl as lv
lv.init()

import SDL
SDL.init()

try:
    print("start")

    disp_buf1 = lv.disp_buf_t()
    buf1_1 = bytearray(480*10)
    print("1")
    disp_buf1.init(buf1_1, None, len(buf1_1)//4)
    disp_drv = lv.disp_drv_t()
    disp_drv.init()
    disp_drv.buffer = disp_buf1
    disp_drv.flush_cb = SDL.monitor_flush

    disp_drv.hor_res = 480
    disp_drv.ver_res = 320
    disp_drv.register()

# Regsiter SDL mouse driver

    indev_drv = lv.indev_drv_t()
    indev_drv.init()
    indev_drv.type = lv.INDEV_TYPE.POINTER;
    indev_drv.read_cb = SDL.mouse_read;
    indev_drv.register();


    
    scr = lv.obj()
    print("1")
    btn = lv.btn(scr)
    print("2")
    btn.align(lv.scr_act(), lv.ALIGN.CENTER, 0, 0)
    label = lv.label(btn)
    label.set_text("Button")
    lv.scr_load(scr)
    time.sleep(5)
    print("end")
except:
    print("Unexpected error:", sys.exc_info()[0])
    raise

Now it works and window blinks for 5 seconds and then program terminates. I suppose I must create loop that do not allow program terminate. How it should look?

2

Please provide more background:
What platform and Micropython port are you running? On what hardware? Which display? How is the display connected?

I don’t see you initialized any display driver so don’t expect to see anything.

3

Thanks for pointing to display driver. I’m trying to run on Raspberry Pi by using SDL. Display is standard HDMI monitor. I have updated question body with code.

Now it works and window blinks for second and then program terminates. I suppose I must create loop that do not allow program terminate. How it should look?

4

Try running:

micropython -i <script_file>

That would open the REPL after running your script.