diff --git a/docs/src/details/auxiliary-modules/observer/observer.rst b/docs/src/details/auxiliary-modules/observer/observer.rst
index 064a1ff07d..dff76c7ac9 100644
--- a/docs/src/details/auxiliary-modules/observer/observer.rst
+++ b/docs/src/details/auxiliary-modules/observer/observer.rst
@@ -456,7 +456,7 @@ Subject's value to be set to ``1`` or ``0`` respectively.
 Specific Widget Types
 ~~~~~~~~~~~~~~~~~~~~~
 
-To learn how to bind subjects to Arcs, Labels, Slider, etc. visit the "Data binding"
+To learn how to bind subjects to Arcs, Labels, Sliders, etc. visit the "Data binding"
 section of the given widget's documentation. For example: :ref:`Data binding for lv_label <lv_label_data_binding>`.
 
 Change Subject on Event
diff --git a/docs/src/details/widgets/label.rst b/docs/src/details/widgets/label.rst
index 8442935ff5..77378ae6f0 100644
--- a/docs/src/details/widgets/label.rst
+++ b/docs/src/details/widgets/label.rst
@@ -197,7 +197,7 @@ To get familiar with observers, subjects, and data bindings in general visit the
 :ref:`Observer <observer_how_to_use>` page.
 
 This method of subscribing to a Subject affects a Label Widget's
-``text``.  The Subject can be an STRING, POINTER or INTEGER type.
+``text``.  The Subject can be a STRING, POINTER, INTEGER, or FLOAT type.
 
 When the subscription occurs, and each time the Subject's value is changed thereafter,
 the Subject's value is used to update the Label's text as follows:
diff --git a/src/widgets/label/lv_label.h b/src/widgets/label/lv_label.h
index 54ccf89c97..ea0382d522 100644
--- a/src/widgets/label/lv_label.h
+++ b/src/widgets/label/lv_label.h
@@ -236,9 +236,8 @@ bool lv_label_get_recolor(const lv_obj_t * obj);
  * @param fmt       optional printf-like format string with 1 format specifier (e.g. "%d °C")
  *                  or NULL to bind to the value directly.
  * @return          pointer to newly-created Observer
- * @note            `fmt == NULL` can be used only with string and pointer Subjects.
- * @note            If Subject is a pointer and `fmt == NULL`, pointer must point
- *                  to a `\0` terminated string.
+ * @note            If `fmt == NULL` strings and pointers (`\0` terminated string) will be shown
+ *                  as text as they are, integers as %d, floats as %0.1f
  */
 lv_observer_t * lv_label_bind_text(lv_obj_t * obj, lv_subject_t * subject, const char * fmt);
 #endif
diff --git a/src/widgets/scale/lv_scale.c b/src/widgets/scale/lv_scale.c
index 5bc400d403..fcb2456eb3 100644
--- a/src/widgets/scale/lv_scale.c
+++ b/src/widgets/scale/lv_scale.c
@@ -528,7 +528,8 @@ int32_t lv_scale_get_range_max_value(lv_obj_t * obj)
 lv_observer_t * lv_scale_bind_section_min_value(lv_obj_t * obj, lv_scale_section_t * section, lv_subject_t * subject)
 {
     LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
+    LV_ASSERT_OBJ(obj, MY_CLASS);
+    LV_ASSERT_NULL(section);
 
     if(subject->type != LV_SUBJECT_TYPE_INT) {
         LV_LOG_WARN("Incompatible subject type: %d", subject->type);
@@ -543,7 +544,8 @@ lv_observer_t * lv_scale_bind_section_min_value(lv_obj_t * obj, lv_scale_section
 lv_observer_t * lv_scale_bind_section_max_value(lv_obj_t * obj, lv_scale_section_t * section, lv_subject_t * subject)
 {
     LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
+    LV_ASSERT_OBJ(obj, MY_CLASS);
+    LV_ASSERT_NULL(section);
 
     if(subject->type != LV_SUBJECT_TYPE_INT) {
         LV_LOG_WARN("Incompatible subject type: %d", subject->type);
diff --git a/src/widgets/slider/lv_slider.h b/src/widgets/slider/lv_slider.h
index dee05ceb00..5fb0120b0b 100644
--- a/src/widgets/slider/lv_slider.h
+++ b/src/widgets/slider/lv_slider.h
@@ -186,7 +186,7 @@ bool lv_slider_is_symmetrical(lv_obj_t * obj);
 
 #if LV_USE_OBSERVER
 /**
- * Bind an integer Subject to a Slider's value.
+ * Bind an integer or float Subject to a Slider's value.
  * @param obj       pointer to Slider
  * @param subject   pointer to Subject
  * @return          pointer to newly-created Observer
diff --git a/src/widgets/span/lv_span.c b/src/widgets/span/lv_span.c
index 554ac3f7b2..f9d4c311ef 100644
--- a/src/widgets/span/lv_span.c
+++ b/src/widgets/span/lv_span.c
@@ -49,6 +49,7 @@ typedef struct {
     void * element; /**< span of a span group*/
     const char * fmt;
 } bind_element_string_t;
+
 /**********************
  *  STATIC PROTOTYPES
  **********************/
diff --git a/src/widgets/span/lv_span.h b/src/widgets/span/lv_span.h
index 8e37b09087..cf20dd05c1 100644
--- a/src/widgets/span/lv_span.h
+++ b/src/widgets/span/lv_span.h
@@ -345,7 +345,6 @@ void lv_spangroup_refresh(lv_obj_t * obj);
  * @param fmt       optional printf-like format string with 1 format specifier (e.g. "%d °C")
  *                  or NULL to bind to the value directly.
  * @return          pointer to newly-created Observer
- * @note            `fmt == NULL` can be used only with string and pointer Subjects.
  * @note            If `fmt == NULL` strings and pointers (`\0` terminated string) will be shown
  *                  as text as they are, integers as %d, floats as %0.1f
  */