About lv_label_set_text_fmt float

EXT · September 8, 2021, 3:16am

lv_label_set_text_fmt(label_current_x,"%f",0.545);

Wrong display character f

embeddedt · September 8, 2021, 7:00pm

There is a setting for this in lv_conf.h.

EXT · September 9, 2021, 12:32am

I can’t find it. Can you tell me？

EXT · September 9, 2021, 12:40am

I don’t want to set font, I want to display floating point and the display character f

embeddedt · September 9, 2021, 12:14pm

If you are not using a custom printf implementation:

github.com

lvgl/lvgl/blob/32e8276db7403d8dc9c9b9f0c77d331049e8c07d/lv_conf_template.h#L222

    
      
          /*1: Draw random colored rectangles over the redrawn areas*/
          #define LV_USE_REFR_DEBUG       0
          
          
/*Change the built in (v)snprintf functions*/
          #define LV_SPRINTF_CUSTOM   0
          #if LV_SPRINTF_CUSTOM
          #  define LV_SPRINTF_INCLUDE <stdio.h>
          #  define lv_snprintf     snprintf
          #  define lv_vsnprintf    vsnprintf
          #else   /*LV_SPRINTF_CUSTOM*/
          #  define LV_SPRINTF_USE_FLOAT 0
          #endif  /*LV_SPRINTF_CUSTOM*/
          
          
#define LV_USE_USER_DATA      1
          
          
/*Garbage Collector settings
           *Used if lvgl is binded to higher level language and the memory is managed by that language*/
          #define LV_ENABLE_GC 0
          #if LV_ENABLE_GC != 0
          #  define LV_GC_INCLUDE "gc.h"                           /*Include Garbage Collector related things*/
          #endif /*LV_ENABLE_GC*/

If you are using a custom printf implementation, you will have to check its configuration.

EXT · September 10, 2021, 12:05am

Good thank you

JadonM · January 23, 2024, 8:05pm

Just an update for those using LVGL V9: I’ve run into this same issue, so here’s what fixes it now.

Set “LV_USE_FLOAT” in the config to 1.

/* Use `float` as `lv_value_precise_t` */
#define LV_USE_FLOAT            1

Lerehmi · June 21, 2024, 4:05pm

Hi,

I am using LVGL V9.1.0, however, setting

#define LV_USE_FLOAT 1

does not work for me. In the lv_conf.h file, I’ve also set

/* clang-format off */
#if 1 /*Set it to "1" to enable content*/

When I use

lv_label_set_text_fmt(maxOD, "Max. OD: %f", maxODValue);

it still gives

Max. OD: f

as output. Any idea what I am missing?