Hi!
I’m facing an issue that I don’t understand. I’m using LVGL with the ESP-IDF on an ESP32-S3 DevKitC 1. Sorry for my english I’m not a native.
What I did
I created a simple rectangle that has a grid layout. Inside this grid I put a label with a time string inside :
lv_obj_t* time_txt = lv_label_create(header);
time_t result = time(NULL);
struct tm *tm_info = localtime(&result);
char buffer[32];
strftime(buffer, sizeof(buffer), "%H:%M:%S %d/%m/%Y", tm_info);
lv_label_set_text(time_txt, buffer);
lv_obj_set_grid_cell(time_txt, LV_GRID_ALIGN_CENTER, 4, 6, LV_GRID_ALIGN_CENTER, 0, 1);
It works well, but I want to create a periodic callback to change it every second (approximately, it’s not important)
lv_timer_create(update_time_txt, 1000, time_txt); // Call this callback every one second
Alright, now in my callback function I have these lines:
void update_time_txt(lv_timer_t* timer) {
lv_obj_t* time_label = (lv_obj_t*)lv_timer_get_user_data(timer);
time_t result = time(NULL);
struct tm *tm_info = localtime(&result);
char buffer[32];
strftime(buffer, sizeof(buffer), "%H:%M:%S %d/%m/%Y", tm_info);
lv_label_set_text(time_label, buffer);
}
Stop me if I’m wrong, but I think I’m good at this moment. I tested it, the callback is triggered every second, the time is getting updated.
The problem
But there is a weird result in my LCD screen. The first text is fine:
But the second one is totally weird, and we can see at the right a 0, probably of the previous text. I don’t know why.
What I tried
To resolv this issue, I tried to put before the lv_label_set_text(time_label, buffer); this line:
lv_label_set_text(time_label, "");, even this line lv_label_set_text(time_label, NULL);.
I tried to remove all of this and I worked with int to see if it was a datetime problem, it is not. Even with int variable and the lv_label_set_text_fmt() function it is the same problem.
What I understand from the documentation is that lv_label_set_text(time_label, buffer); saves buffer in the memory, so buffer can be deleted, it will be printed anyway (not like lv_label_set_text_static().
The question
So how can I update my text every second to show the time ?
Thank you in advance.