diff --git a/src/others/observer/lv_observer.c b/src/others/observer/lv_observer.c
index 15cf46ed02..6d328574f6 100644
--- a/src/others/observer/lv_observer.c
+++ b/src/others/observer/lv_observer.c
@@ -55,12 +55,6 @@ typedef struct {
     const char * value;
 } subject_set_string_user_data_t;
 
-typedef struct {
-    lv_subject_t * subject;
-    void * element; /**< E.g. span of a span group*/
-    const char * fmt;
-} bind_element_string_t;
-
 typedef struct {
     lv_subject_t * subject;
     int32_t step;
@@ -93,39 +87,6 @@ static void obj_value_changed_event_cb(lv_event_t * e);
 
 static void lv_subject_notify_if_changed(lv_subject_t * subject);
 
-#if LV_USE_LABEL
-    static void label_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-#endif
-
-#if LV_USE_SPAN
-    static void span_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-#endif
-
-#if LV_USE_ARC
-    static void arc_value_changed_event_cb(lv_event_t * e);
-    static void arc_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-#endif
-
-#if LV_USE_SLIDER
-    static void slider_value_changed_event_cb(lv_event_t * e);
-    static void slider_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-#endif
-
-#if LV_USE_ROLLER
-    static void roller_value_changed_event_cb(lv_event_t * e);
-    static void roller_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-#endif
-
-#if LV_USE_DROPDOWN
-    static void dropdown_value_changed_event_cb(lv_event_t * e);
-    static void dropdown_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-#endif
-
-#if LV_USE_SCALE
-    static void scale_section_min_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-    static void scale_section_max_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
-#endif
-
 static void subject_set_string_free_user_data_event_cb(lv_event_t * e);
 
 /**********************
@@ -759,192 +720,6 @@ lv_observer_t * lv_obj_bind_checked(lv_obj_t * obj, lv_subject_t * subject)
     return observable;
 }
 
-#if LV_USE_LABEL
-lv_observer_t * lv_label_bind_text(lv_obj_t * obj, lv_subject_t * subject, const char * fmt)
-{
-    LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
-
-    if(fmt == NULL) {
-        if(subject->type == LV_SUBJECT_TYPE_INT) {
-            fmt = "%d";
-        }
-#if LV_USE_FLOAT
-        else if(subject->type == LV_SUBJECT_TYPE_FLOAT) {
-            fmt = "%0.1f";
-        }
-#endif
-        else if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER) {
-            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-            return NULL;
-        }
-    }
-    else {
-        if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER &&
-           subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
-            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-            return NULL;
-        }
-    }
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, label_text_observer_cb, obj, (void *)fmt);
-    return observer;
-}
-#endif /*LV_USE_LABEL*/
-
-#if LV_USE_SPAN
-lv_observer_t * lv_spangroup_bind_span_text(lv_obj_t * obj, lv_span_t * span, lv_subject_t * subject, const char * fmt)
-{
-    LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
-    LV_ASSERT_NULL(span);
-
-    if(fmt == NULL) {
-        if(subject->type == LV_SUBJECT_TYPE_INT) {
-            fmt = "%d";
-        }
-#if LV_USE_FLOAT
-        else if(subject->type == LV_SUBJECT_TYPE_FLOAT) {
-            fmt = "%0.1f";
-        }
-#endif
-        else if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER) {
-            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-            return NULL;
-        }
-    }
-    else {
-        if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER &&
-           subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
-            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-            return NULL;
-        }
-    }
-
-    bind_element_string_t * user_data = lv_zalloc(sizeof(bind_element_string_t));
-    if(user_data == NULL) {
-        LV_LOG_WARN("Couldn't allocate user_data");
-        LV_ASSERT_MALLOC(user_data);
-        return NULL;
-    }
-
-    user_data->subject = subject;
-    user_data->element = span;
-    user_data->fmt = fmt;
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, span_text_observer_cb, obj, user_data);
-    observer->auto_free_user_data = 1;
-
-    return observer;
-}
-#endif /*LV_USE_SPAN*/
-
-
-#if LV_USE_ARC
-lv_observer_t * lv_arc_bind_value(lv_obj_t * obj, lv_subject_t * subject)
-{
-    LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
-
-    if(subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
-        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-        return NULL;
-    }
-
-    lv_obj_add_event_cb(obj, arc_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, arc_value_observer_cb, obj, NULL);
-    return observer;
-}
-#endif /*LV_USE_ARC*/
-
-#if LV_USE_SLIDER
-lv_observer_t * lv_slider_bind_value(lv_obj_t * obj, lv_subject_t * subject)
-{
-    LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
-
-    if(subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
-        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-        return NULL;
-    }
-
-    lv_obj_add_event_cb(obj, slider_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, slider_value_observer_cb, obj, NULL);
-    return observer;
-}
-#endif /*LV_USE_SLIDER*/
-
-#if LV_USE_ROLLER
-lv_observer_t * lv_roller_bind_value(lv_obj_t * obj, lv_subject_t * subject)
-{
-    LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
-
-    if(subject->type != LV_SUBJECT_TYPE_INT) {
-        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-        return NULL;
-    }
-
-    lv_obj_add_event_cb(obj, roller_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, roller_value_observer_cb, obj, NULL);
-    return observer;
-}
-#endif /*LV_USE_ROLLER*/
-
-#if LV_USE_DROPDOWN
-lv_observer_t * lv_dropdown_bind_value(lv_obj_t * obj, lv_subject_t * subject)
-{
-    LV_ASSERT_NULL(subject);
-    LV_ASSERT_NULL(obj);
-
-    if(subject->type != LV_SUBJECT_TYPE_INT) {
-        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-        return NULL;
-    }
-
-    lv_obj_add_event_cb(obj, dropdown_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, dropdown_value_observer_cb, obj, NULL);
-    return observer;
-}
-#endif /*LV_USE_DROPDOWN*/
-
-#if LV_USE_SCALE
-
-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);
-
-    if(subject->type != LV_SUBJECT_TYPE_INT) {
-        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-        return NULL;
-    }
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, scale_section_min_value_observer_cb, obj, section);
-
-    return observer;
-}
-
-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);
-
-    if(subject->type != LV_SUBJECT_TYPE_INT) {
-        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
-        return NULL;
-    }
-
-    lv_observer_t * observer = lv_subject_add_observer_obj(subject, scale_section_max_value_observer_cb, obj, section);
-
-    return observer;
-}
-
-#endif /*LV_USE_SCALE*/
 
 lv_obj_t * lv_observer_get_target_obj(lv_observer_t * observer)
 {
@@ -1154,184 +929,6 @@ static void lv_subject_notify_if_changed(lv_subject_t * subject)
     }
 }
 
-#if LV_USE_LABEL
-
-static void label_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    const char * fmt = observer->user_data;
-
-    if(fmt == NULL) {
-        lv_label_set_text(observer->target, subject->value.pointer);
-    }
-    else {
-        switch(subject->type) {
-            case LV_SUBJECT_TYPE_INT:
-                lv_label_set_text_fmt(observer->target, fmt, subject->value.num);
-                break;
-#if LV_USE_FLOAT
-            case LV_SUBJECT_TYPE_FLOAT:
-                lv_label_set_text_fmt(observer->target, fmt, subject->value.float_v);
-                break;
-#endif
-            case LV_SUBJECT_TYPE_STRING:
-            case LV_SUBJECT_TYPE_POINTER:
-                lv_label_set_text_fmt(observer->target, fmt, subject->value.pointer);
-                break;
-            default:
-                break;
-        }
-    }
-}
-
-#endif /*LV_USE_LABEL*/
-
-#if LV_USE_SPAN
-
-static void span_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    bind_element_string_t * user_data = observer->user_data;
-
-    if(user_data->fmt == NULL) {
-        lv_spangroup_set_span_text(observer->target, user_data->element, subject->value.pointer);
-    }
-    else {
-        switch(subject->type) {
-
-            case LV_SUBJECT_TYPE_INT:
-                lv_spangroup_set_span_text_fmt(observer->target, user_data->element, user_data->fmt, subject->value.num);
-                break;
-#if LV_USE_FLOAT
-            case LV_SUBJECT_TYPE_FLOAT:
-                lv_spangroup_set_span_text_fmt(observer->target, user_data->element, user_data->fmt, subject->value.float_v);
-                break;
-#endif
-            case LV_SUBJECT_TYPE_STRING:
-            case LV_SUBJECT_TYPE_POINTER:
-                lv_spangroup_set_span_text_fmt(observer->target, user_data->element, user_data->fmt, subject->value.pointer);
-                break;
-            default:
-                return;
-        }
-    }
-}
-
-#endif /*LV_USE_SPAN*/
-
-
-#if LV_USE_ARC
-
-static void arc_value_changed_event_cb(lv_event_t * e)
-{
-    lv_obj_t * arc = lv_event_get_current_target(e);
-    lv_subject_t * subject = lv_event_get_user_data(e);
-
-    if(subject->type == LV_SUBJECT_TYPE_INT) {
-        lv_subject_set_int(subject, lv_arc_get_value(arc));
-    }
-#if LV_USE_FLOAT
-    else {
-        lv_subject_set_float(subject, (float)lv_arc_get_value(arc));
-    }
-#endif
-}
-
-static void arc_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    if(subject->type == LV_SUBJECT_TYPE_INT) {
-        lv_arc_set_value(observer->target, subject->value.num);
-    }
-#if LV_USE_FLOAT
-    else {
-        lv_arc_set_value(observer->target, (int32_t)subject->value.float_v);
-    }
-#endif
-}
-
-#endif /*LV_USE_ARC*/
-
-#if LV_USE_SLIDER
-
-static void slider_value_changed_event_cb(lv_event_t * e)
-{
-    lv_obj_t * slider = lv_event_get_current_target(e);
-    lv_subject_t * subject = lv_event_get_user_data(e);
-
-    if(subject->type == LV_SUBJECT_TYPE_INT) {
-        lv_subject_set_int(subject, lv_slider_get_value(slider));
-    }
-#if LV_USE_FLOAT
-    else {
-        lv_subject_set_float(subject, (float)lv_slider_get_value(slider));
-    }
-#endif
-}
-
-static void slider_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    if(subject->type == LV_SUBJECT_TYPE_INT) {
-        lv_slider_set_value(observer->target, subject->value.num, LV_ANIM_OFF);
-    }
-#if LV_USE_FLOAT
-    else {
-        lv_slider_set_value(observer->target, (int32_t)subject->value.float_v, LV_ANIM_OFF);
-    }
-#endif
-}
-
-#endif /*LV_USE_SLIDER*/
-
-#if LV_USE_ROLLER
-
-static void roller_value_changed_event_cb(lv_event_t * e)
-{
-    lv_obj_t * roller = lv_event_get_current_target(e);
-    lv_subject_t * subject = lv_event_get_user_data(e);
-
-    lv_subject_set_int(subject, lv_roller_get_selected(roller));
-}
-
-static void roller_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    if((int32_t)lv_roller_get_selected(observer->target) != subject->value.num) {
-        lv_roller_set_selected(observer->target, subject->value.num, LV_ANIM_OFF);
-    }
-}
-
-#endif /*LV_USE_ROLLER*/
-
-#if LV_USE_DROPDOWN
-
-static void dropdown_value_changed_event_cb(lv_event_t * e)
-{
-    lv_obj_t * dropdown = lv_event_get_current_target(e);
-    lv_subject_t * subject = lv_event_get_user_data(e);
-
-    lv_subject_set_int(subject, lv_dropdown_get_selected(dropdown));
-}
-
-static void dropdown_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    lv_dropdown_set_selected(observer->target, subject->value.num);
-}
-
-#endif /*LV_USE_DROPDOWN*/
-
-#if LV_USE_SCALE
-
-static void scale_section_min_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    lv_scale_section_t * section = observer->user_data;
-    lv_scale_set_section_min_value(observer->target, section, subject->value.num);
-}
-
-static void scale_section_max_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
-{
-    lv_scale_section_t * section = observer->user_data;
-    lv_scale_set_section_max_value(observer->target, section, subject->value.num);
-}
-
-#endif /*LV_USE_SCALE*/
-
 static void subject_set_string_free_user_data_event_cb(lv_event_t * e)
 {
     subject_set_string_user_data_t * user_data = lv_event_get_user_data(e);
diff --git a/src/others/observer/lv_observer.h b/src/others/observer/lv_observer.h
index f1fc68d32d..d2eeb67213 100644
--- a/src/others/observer/lv_observer.h
+++ b/src/others/observer/lv_observer.h
@@ -530,100 +530,6 @@ lv_observer_t * lv_obj_bind_state_if_le(lv_obj_t * obj, lv_subject_t * subject,
  */
 lv_observer_t * lv_obj_bind_checked(lv_obj_t * obj, lv_subject_t * subject);
 
-#if LV_USE_LABEL
-/**
- * Bind an integer, string, or pointer Subject to a Label.
- * @param obj       pointer to Label
- * @param subject   pointer to Subject
- * @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.
- */
-lv_observer_t * lv_label_bind_text(lv_obj_t * obj, lv_subject_t * subject, const char * fmt);
-#endif
-
-#if LV_USE_SPAN
-
-/**
- * Bind an integer, string, or pointer Subject to a Spangroup's Span.
- * @param obj       pointer to Spangroup
- * @param span      pointer to Span
- * @param subject   pointer to Subject
- * @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
- */
-lv_observer_t * lv_spangroup_bind_span_text(lv_obj_t * obj, lv_span_t * span, lv_subject_t * subject, const char * fmt);
-
-#endif
-
-#if LV_USE_ARC
-/**
- * Bind an integer subject to an Arc's value.
- * @param obj       pointer to Arc
- * @param subject   pointer to Subject
- * @return          pointer to newly-created Observer
- */
-lv_observer_t * lv_arc_bind_value(lv_obj_t * obj, lv_subject_t * subject);
-#endif
-
-#if LV_USE_SLIDER
-/**
- * Bind an integer Subject to a Slider's value.
- * @param obj       pointer to Slider
- * @param subject   pointer to Subject
- * @return          pointer to newly-created Observer
- */
-lv_observer_t * lv_slider_bind_value(lv_obj_t * obj, lv_subject_t * subject);
-#endif
-
-#if LV_USE_ROLLER
-/**
- * Bind an integer Subject to a Roller's value.
- * @param obj       pointer to Roller
- * @param subject   pointer to Subject
- * @return          pointer to newly-created Observer
- */
-lv_observer_t * lv_roller_bind_value(lv_obj_t * obj, lv_subject_t * subject);
-#endif
-
-#if LV_USE_DROPDOWN
-/**
- * Bind an integer Subject to a Dropdown's value.
- * @param obj       pointer to Dropdown
- * @param subject   pointer to Subject
- * @return          pointer to newly-created Observer
- */
-lv_observer_t * lv_dropdown_bind_value(lv_obj_t * obj, lv_subject_t * subject);
-#endif
-
-#if LV_USE_SCALE
-
-/**
- * Bind an integer subject to a scales section minimum value
- * @param obj       pointer to a Scale
- * @param section   pointer to a Scale section
- * @param subject   pointer to a Subject
- * @return          pointer to newly-created Observer
- */
-lv_observer_t * lv_scale_bind_section_min_value(lv_obj_t * obj, lv_scale_section_t * section, lv_subject_t * subject);
-
-/**
- * Bind an integer subject to a scales section maximum value
- * @param obj       pointer to an Scale
- * @param section   pointer to a Scale section
- * @param subject   pointer to a Subject
- * @return          pointer to newly-created Observer
- */
-lv_observer_t * lv_scale_bind_section_max_value(lv_obj_t * obj, lv_scale_section_t * section, lv_subject_t * subject);
-
-#endif
 
 /**********************
  *      MACROS
diff --git a/src/widgets/arc/lv_arc.c b/src/widgets/arc/lv_arc.c
index 201452a3e0..4a683ee4b8 100644
--- a/src/widgets/arc/lv_arc.c
+++ b/src/widgets/arc/lv_arc.c
@@ -18,6 +18,7 @@
 #include "../../misc/lv_assert.h"
 #include "../../misc/lv_math.h"
 #include "../../draw/lv_draw_arc.h"
+#include "../../others/observer/lv_observer_private.h"
 
 /*********************
  *      DEFINES
@@ -50,6 +51,10 @@ static void value_update(lv_obj_t * arc);
 static int32_t knob_get_extra_size(lv_obj_t * obj);
 static bool lv_arc_angle_within_bg_bounds(lv_obj_t * obj, const lv_value_precise_t angle,
                                           const lv_value_precise_t tolerance_deg);
+#if LV_USE_OBSERVER
+    static void arc_value_changed_event_cb(lv_event_t * e);
+    static void arc_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+#endif /*LV_USE_OBSERVER*/
 
 /**********************
  *  STATIC VARIABLES
@@ -367,6 +372,25 @@ int32_t lv_arc_get_knob_offset(const lv_obj_t * obj)
  * Other functions
  *====================*/
 
+#if LV_USE_OBSERVER
+lv_observer_t * lv_arc_bind_value(lv_obj_t * obj, lv_subject_t * subject)
+{
+    LV_ASSERT_NULL(subject);
+    LV_ASSERT_NULL(obj);
+
+    if(subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
+        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+        return NULL;
+    }
+
+    lv_obj_add_event_cb(obj, arc_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, arc_value_observer_cb, obj, NULL);
+    return observer;
+}
+#endif /*LV_USE_OBSERVER*/
+
+
 void lv_arc_align_obj_to_angle(const lv_obj_t * obj, lv_obj_t * obj_to_align, int32_t r_offset)
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
@@ -1025,4 +1049,36 @@ static bool lv_arc_angle_within_bg_bounds(lv_obj_t * obj, const lv_value_precise
     return false;
 }
 
+#if LV_USE_OBSERVER
+
+static void arc_value_changed_event_cb(lv_event_t * e)
+{
+    lv_obj_t * arc = lv_event_get_current_target(e);
+    lv_subject_t * subject = lv_event_get_user_data(e);
+
+    if(subject->type == LV_SUBJECT_TYPE_INT) {
+        lv_subject_set_int(subject, lv_arc_get_value(arc));
+    }
+#if LV_USE_FLOAT
+    else {
+        lv_subject_set_float(subject, (float)lv_arc_get_value(arc));
+    }
+#endif
+}
+
+static void arc_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    if(subject->type == LV_SUBJECT_TYPE_INT) {
+        lv_arc_set_value(observer->target, subject->value.num);
+    }
+#if LV_USE_FLOAT
+    else {
+        lv_arc_set_value(observer->target, (int32_t)subject->value.float_v);
+    }
+#endif
+}
+
+#endif /*LV_USE_OBSERVER*/
+
+
 #endif
diff --git a/src/widgets/arc/lv_arc.h b/src/widgets/arc/lv_arc.h
index 18c2dbc7ad..a96400ba0d 100644
--- a/src/widgets/arc/lv_arc.h
+++ b/src/widgets/arc/lv_arc.h
@@ -18,6 +18,7 @@ extern "C" {
 #if LV_USE_ARC != 0
 
 #include "../../core/lv_obj.h"
+#include "../../others/observer/lv_observer.h"
 
 /*********************
  *      DEFINES
@@ -232,6 +233,17 @@ int32_t lv_arc_get_knob_offset(const lv_obj_t * obj);
  * Other functions
  *====================*/
 
+#if LV_USE_OBSERVER
+/**
+ * Bind an integer subject to an Arc's value.
+ * @param obj       pointer to Arc
+ * @param subject   pointer to Subject
+ * @return          pointer to newly-created Observer
+ */
+lv_observer_t * lv_arc_bind_value(lv_obj_t * obj, lv_subject_t * subject);
+#endif
+
+
 /**
  * Align an object to the current position of the arc (knob)
  * @param obj           pointer to an arc object
diff --git a/src/widgets/bar/lv_bar.h b/src/widgets/bar/lv_bar.h
index 7e9953e116..17a1208ddf 100644
--- a/src/widgets/bar/lv_bar.h
+++ b/src/widgets/bar/lv_bar.h
@@ -20,6 +20,7 @@ extern "C" {
 #include "../../core/lv_obj.h"
 #include "../../misc/lv_anim.h"
 #include "../label/lv_label.h"
+#include "../../others/observer/lv_observer.h"
 
 /*********************
  *      DEFINES
diff --git a/src/widgets/dropdown/lv_dropdown.c b/src/widgets/dropdown/lv_dropdown.c
index b16ec89b93..db15f1c5a1 100644
--- a/src/widgets/dropdown/lv_dropdown.c
+++ b/src/widgets/dropdown/lv_dropdown.c
@@ -22,6 +22,7 @@
 #include "../../misc/lv_math.h"
 #include "../../misc/lv_text_ap.h"
 #include "../../misc/lv_text_private.h"
+#include "../../others/observer/lv_observer_private.h"
 #include "../../stdlib/lv_string.h"
 
 /*********************
@@ -59,6 +60,11 @@ static uint32_t get_id_on_point(lv_obj_t * dropdown_obj, int32_t y);
 static void position_to_selected(lv_obj_t * dropdown_obj, lv_anim_enable_t anim_en);
 static lv_obj_t * get_label(const lv_obj_t * obj);
 
+#if LV_USE_OBSERVER
+    static void dropdown_value_changed_event_cb(lv_event_t * e);
+    static void dropdown_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+#endif /*LV_USE_OBSERVER*/
+
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -636,6 +642,27 @@ bool lv_dropdown_is_open(lv_obj_t * obj)
     return lv_obj_has_flag(dropdown->list, LV_OBJ_FLAG_HIDDEN) ? false : true;
 }
 
+#if LV_USE_OBSERVER
+
+lv_observer_t * lv_dropdown_bind_value(lv_obj_t * obj, lv_subject_t * subject)
+{
+    LV_ASSERT_NULL(subject);
+    LV_ASSERT_NULL(obj);
+
+    if(subject->type != LV_SUBJECT_TYPE_INT) {
+        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+        return NULL;
+    }
+
+    lv_obj_add_event_cb(obj, dropdown_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, dropdown_value_observer_cb, obj, NULL);
+    return observer;
+}
+#endif /*LV_USE_OBSERVER*/
+
+
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/
@@ -1257,4 +1284,22 @@ static lv_obj_t * get_label(const lv_obj_t * obj)
     return lv_obj_get_child(dropdown->list, 0);
 }
 
+#if LV_USE_OBSERVER
+
+static void dropdown_value_changed_event_cb(lv_event_t * e)
+{
+    lv_obj_t * dropdown = lv_event_get_current_target(e);
+    lv_subject_t * subject = lv_event_get_user_data(e);
+
+    lv_subject_set_int(subject, lv_dropdown_get_selected(dropdown));
+}
+
+static void dropdown_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    lv_dropdown_set_selected(observer->target, subject->value.num);
+}
+
+#endif /*LV_USE_OBSERVER*/
+
+
 #endif
diff --git a/src/widgets/dropdown/lv_dropdown.h b/src/widgets/dropdown/lv_dropdown.h
index 07bbd0e840..a65f50d4a6 100644
--- a/src/widgets/dropdown/lv_dropdown.h
+++ b/src/widgets/dropdown/lv_dropdown.h
@@ -233,6 +233,17 @@ void lv_dropdown_close(lv_obj_t * obj);
  */
 bool lv_dropdown_is_open(lv_obj_t * obj);
 
+
+#if LV_USE_OBSERVER
+/**
+ * Bind an integer Subject to a Dropdown's value.
+ * @param obj       pointer to Dropdown
+ * @param subject   pointer to Subject
+ * @return          pointer to newly-created Observer
+ */
+lv_observer_t * lv_dropdown_bind_value(lv_obj_t * obj, lv_subject_t * subject);
+#endif
+
 /**********************
  *      MACROS
  **********************/
diff --git a/src/widgets/label/lv_label.c b/src/widgets/label/lv_label.c
index 0ca8b99f10..9f947bcb86 100644
--- a/src/widgets/label/lv_label.c
+++ b/src/widgets/label/lv_label.c
@@ -24,6 +24,7 @@
 #include "../../misc/lv_text_private.h"
 #include "../../stdlib/lv_sprintf.h"
 #include "../../stdlib/lv_string.h"
+#include "../../others/observer/lv_observer_private.h"
 
 /*********************
  *      DEFINES
@@ -59,6 +60,10 @@ static lv_text_flag_t get_label_flags(lv_label_t * label);
 static void calculate_x_coordinate(int32_t * x, const lv_text_align_t align, const char * txt,
                                    uint32_t length, const lv_font_t * font, lv_area_t * txt_coords, lv_text_attributes_t * attributes);
 
+#if LV_USE_OBSERVER
+    static void label_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+#endif
+
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -664,6 +669,40 @@ bool lv_label_get_recolor(const lv_obj_t * obj)
  * Other functions
  *====================*/
 
+#if LV_USE_OBSERVER
+lv_observer_t * lv_label_bind_text(lv_obj_t * obj, lv_subject_t * subject, const char * fmt)
+{
+    LV_ASSERT_NULL(subject);
+    LV_ASSERT_NULL(obj);
+
+    if(fmt == NULL) {
+        if(subject->type == LV_SUBJECT_TYPE_INT) {
+            fmt = "%d";
+        }
+#if LV_USE_FLOAT
+        else if(subject->type == LV_SUBJECT_TYPE_FLOAT) {
+            fmt = "%0.1f";
+        }
+#endif
+        else if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER) {
+            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+            return NULL;
+        }
+    }
+    else {
+        if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER &&
+           subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
+            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+            return NULL;
+        }
+    }
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, label_text_observer_cb, obj, (void *)fmt);
+    return observer;
+}
+#endif /*LV_USE_OBSERVER*/
+
+
 void lv_label_ins_text(lv_obj_t * obj, uint32_t pos, const char * txt)
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
@@ -710,6 +749,8 @@ void lv_label_cut_text(lv_obj_t * obj, uint32_t pos, uint32_t cnt)
     lv_label_refr_text(obj);
 }
 
+
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/
@@ -1331,4 +1372,36 @@ static void calculate_x_coordinate(int32_t * x, const lv_text_align_t align, con
     }
 }
 
+#if LV_USE_OBSERVER
+
+static void label_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    const char * fmt = observer->user_data;
+
+    if(fmt == NULL) {
+        lv_label_set_text(observer->target, subject->value.pointer);
+    }
+    else {
+        switch(subject->type) {
+            case LV_SUBJECT_TYPE_INT:
+                lv_label_set_text_fmt(observer->target, fmt, subject->value.num);
+                break;
+#if LV_USE_FLOAT
+            case LV_SUBJECT_TYPE_FLOAT:
+                lv_label_set_text_fmt(observer->target, fmt, subject->value.float_v);
+                break;
+#endif
+            case LV_SUBJECT_TYPE_STRING:
+            case LV_SUBJECT_TYPE_POINTER:
+                lv_label_set_text_fmt(observer->target, fmt, subject->value.pointer);
+                break;
+            default:
+                break;
+        }
+    }
+}
+
+#endif /*LV_USE_LABEL*/
+
+
 #endif
diff --git a/src/widgets/label/lv_label.h b/src/widgets/label/lv_label.h
index b71cc7bafa..54ccf89c97 100644
--- a/src/widgets/label/lv_label.h
+++ b/src/widgets/label/lv_label.h
@@ -23,6 +23,7 @@ extern "C" {
 #include "../../font/lv_symbol_def.h"
 #include "../../misc/lv_text.h"
 #include "../../draw/lv_draw.h"
+#include "../../others/observer/lv_observer.h"
 
 /*********************
  *      DEFINES
@@ -227,6 +228,22 @@ bool lv_label_get_recolor(const lv_obj_t * obj);
  * Other functions
  *====================*/
 
+#if LV_USE_OBSERVER
+/**
+ * Bind an integer, string, or pointer Subject to a Label.
+ * @param obj       pointer to Label
+ * @param subject   pointer to Subject
+ * @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.
+ */
+lv_observer_t * lv_label_bind_text(lv_obj_t * obj, lv_subject_t * subject, const char * fmt);
+#endif
+
+
 /**
  * Insert a text to a label. The label text cannot be static.
  * @param obj       pointer to a label object
@@ -245,6 +262,8 @@ void lv_label_ins_text(lv_obj_t * obj, uint32_t pos, const char * txt);
  */
 void lv_label_cut_text(lv_obj_t * obj, uint32_t pos, uint32_t cnt);
 
+
+
 /**********************
  *      MACROS
  **********************/
diff --git a/src/widgets/roller/lv_roller.c b/src/widgets/roller/lv_roller.c
index 3966024bd3..7780f0c15f 100644
--- a/src/widgets/roller/lv_roller.c
+++ b/src/widgets/roller/lv_roller.c
@@ -22,6 +22,7 @@
 #include "../../indev/lv_indev_scroll.h"
 #include "../../indev/lv_indev_private.h"
 #include "../../stdlib/lv_string.h"
+#include "../../others/observer/lv_observer_private.h"
 
 /*********************
  *      DEFINES
@@ -52,6 +53,11 @@ static void scroll_anim_completed_cb(lv_anim_t * a);
 static void set_y_anim(void * obj, int32_t v);
 static void transform_vect_recursive(lv_obj_t * roller, lv_point_t * vect);
 
+#if LV_USE_OBSERVER
+    static void roller_value_changed_event_cb(lv_event_t * e);
+    static void roller_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+#endif /*LV_USE_OBSERVER*/
+
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -328,6 +334,25 @@ uint32_t lv_roller_get_option_count(const lv_obj_t * obj)
     }
 }
 
+#if LV_USE_OBSERVER
+
+lv_observer_t * lv_roller_bind_value(lv_obj_t * obj, lv_subject_t * subject)
+{
+    LV_ASSERT_NULL(subject);
+    LV_ASSERT_NULL(obj);
+
+    if(subject->type != LV_SUBJECT_TYPE_INT) {
+        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+        return NULL;
+    }
+
+    lv_obj_add_event_cb(obj, roller_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, roller_value_observer_cb, obj, NULL);
+    return observer;
+}
+#endif /*LV_USE_OBSERVER*/
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/
@@ -915,4 +940,24 @@ static void transform_vect_recursive(lv_obj_t * roller, lv_point_t * vect)
     lv_point_transform(vect, -angle, scale_x, scale_y, &pivot, false);
 }
 
+#if LV_USE_OBSERVER
+
+static void roller_value_changed_event_cb(lv_event_t * e)
+{
+    lv_obj_t * roller = lv_event_get_current_target(e);
+    lv_subject_t * subject = lv_event_get_user_data(e);
+
+    lv_subject_set_int(subject, lv_roller_get_selected(roller));
+}
+
+static void roller_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    if((int32_t)lv_roller_get_selected(observer->target) != subject->value.num) {
+        lv_roller_set_selected(observer->target, subject->value.num, LV_ANIM_OFF);
+    }
+}
+
+#endif /*LV_USE_OBSERVER*/
+
+
 #endif
diff --git a/src/widgets/roller/lv_roller.h b/src/widgets/roller/lv_roller.h
index 37d94bed0d..7f960c7dcc 100644
--- a/src/widgets/roller/lv_roller.h
+++ b/src/widgets/roller/lv_roller.h
@@ -129,6 +129,17 @@ const char * lv_roller_get_options(const lv_obj_t * obj);
  */
 uint32_t lv_roller_get_option_count(const lv_obj_t * obj);
 
+
+#if LV_USE_OBSERVER
+/**
+ * Bind an integer Subject to a Roller's value.
+ * @param obj       pointer to Roller
+ * @param subject   pointer to Subject
+ * @return          pointer to newly-created Observer
+ */
+lv_observer_t * lv_roller_bind_value(lv_obj_t * obj, lv_subject_t * subject);
+#endif
+
 /**********************
  *      MACROS
  **********************/
diff --git a/src/widgets/scale/lv_scale.c b/src/widgets/scale/lv_scale.c
index 961a768c34..5bc400d403 100644
--- a/src/widgets/scale/lv_scale.c
+++ b/src/widgets/scale/lv_scale.c
@@ -15,6 +15,7 @@
 #include "../../misc/lv_assert.h"
 #include "../../misc/lv_math.h"
 #include "../../misc/lv_text_private.h"
+#include "../../others/observer/lv_observer_private.h"
 #include "../../draw/lv_draw_arc.h"
 
 /*********************
@@ -70,6 +71,11 @@ static void scale_free_line_needle_points_cb(lv_event_t * e);
 
 static bool scale_is_major_tick(lv_scale_t * scale, uint32_t tick_idx);
 
+#if LV_USE_OBSERVER
+    static void scale_section_min_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+    static void scale_section_max_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+#endif /*LV_USE_OBSERVER*/
+
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -517,6 +523,40 @@ int32_t lv_scale_get_range_max_value(lv_obj_t * obj)
  * Other functions
  *====================*/
 
+#if LV_USE_OBSERVER
+
+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);
+
+    if(subject->type != LV_SUBJECT_TYPE_INT) {
+        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+        return NULL;
+    }
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, scale_section_min_value_observer_cb, obj, section);
+
+    return observer;
+}
+
+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);
+
+    if(subject->type != LV_SUBJECT_TYPE_INT) {
+        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+        return NULL;
+    }
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, scale_section_max_value_observer_cb, obj, section);
+
+    return observer;
+}
+
+#endif /*LV_USE_OBSERVER*/
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/
@@ -1719,4 +1759,21 @@ static bool scale_is_major_tick(lv_scale_t * scale, uint32_t tick_idx)
     return scale->major_tick_every != 0 && tick_idx % scale->major_tick_every == 0;
 }
 
+#if LV_USE_OBSERVER
+
+static void scale_section_min_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    lv_scale_section_t * section = observer->user_data;
+    lv_scale_set_section_min_value(observer->target, section, subject->value.num);
+}
+
+static void scale_section_max_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    lv_scale_section_t * section = observer->user_data;
+    lv_scale_set_section_max_value(observer->target, section, subject->value.num);
+}
+
+#endif /*LV_USE_OBSERVER*/
+
+
 #endif
diff --git a/src/widgets/scale/lv_scale.h b/src/widgets/scale/lv_scale.h
index a5b856d900..642259a3b7 100644
--- a/src/widgets/scale/lv_scale.h
+++ b/src/widgets/scale/lv_scale.h
@@ -20,6 +20,7 @@ extern "C" {
 #include "../../core/lv_obj.h"
 #include "../line/lv_line.h"
 #include "../image/lv_image.h"
+#include "../../others/observer/lv_observer.h"
 
 /*********************
  *      DEFINES
@@ -344,6 +345,32 @@ int32_t lv_scale_get_range_min_value(lv_obj_t * obj);
  */
 int32_t lv_scale_get_range_max_value(lv_obj_t * obj);
 
+/*=====================
+ * Other functions
+ *====================*/
+
+#if LV_USE_OBSERVER
+
+/**
+ * Bind an integer subject to a scales section minimum value
+ * @param obj       pointer to a Scale
+ * @param section   pointer to a Scale section
+ * @param subject   pointer to a Subject
+ * @return          pointer to newly-created Observer
+ */
+lv_observer_t * lv_scale_bind_section_min_value(lv_obj_t * obj, lv_scale_section_t * section, lv_subject_t * subject);
+
+/**
+ * Bind an integer subject to a scales section maximum value
+ * @param obj       pointer to an Scale
+ * @param section   pointer to a Scale section
+ * @param subject   pointer to a Subject
+ * @return          pointer to newly-created Observer
+ */
+lv_observer_t * lv_scale_bind_section_max_value(lv_obj_t * obj, lv_scale_section_t * section, lv_subject_t * subject);
+
+#endif
+
 /**********************
  *      MACROS
  **********************/
diff --git a/src/widgets/slider/lv_slider.c b/src/widgets/slider/lv_slider.c
index 99a8c54d2d..89fe595d80 100644
--- a/src/widgets/slider/lv_slider.c
+++ b/src/widgets/slider/lv_slider.c
@@ -22,6 +22,7 @@
 #include "../../stdlib/lv_string.h"
 #include "../../misc/lv_math.h"
 #include "../image/lv_image.h"
+#include "../../others/observer/lv_observer_private.h"
 
 /*********************
  *      DEFINES
@@ -46,6 +47,11 @@ static bool is_slider_horizontal(lv_obj_t * obj);
 static void drag_start(lv_obj_t * obj);
 static void update_knob_pos(lv_obj_t * obj, bool check_drag);
 
+#if LV_USE_OBSERVER
+    static void slider_value_changed_event_cb(lv_event_t * e);
+    static void slider_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+#endif /*LV_USE_OBSERVER*/
+
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -216,6 +222,25 @@ bool lv_slider_is_symmetrical(lv_obj_t * obj)
     return lv_bar_is_symmetrical(obj);
 }
 
+#if LV_USE_OBSERVER
+lv_observer_t * lv_slider_bind_value(lv_obj_t * obj, lv_subject_t * subject)
+{
+    LV_ASSERT_NULL(subject);
+    LV_ASSERT_NULL(obj);
+
+    if(subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
+        LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+        return NULL;
+    }
+
+    lv_obj_add_event_cb(obj, slider_value_changed_event_cb, LV_EVENT_VALUE_CHANGED, subject);
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, slider_value_observer_cb, obj, NULL);
+    return observer;
+}
+#endif /*LV_USE_OBSERVER*/
+
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/
@@ -637,4 +662,37 @@ static void update_knob_pos(lv_obj_t * obj, bool check_drag)
     }
 }
 
+
+#if LV_USE_OBSERVER
+
+static void slider_value_changed_event_cb(lv_event_t * e)
+{
+    lv_obj_t * slider = lv_event_get_current_target(e);
+    lv_subject_t * subject = lv_event_get_user_data(e);
+
+    if(subject->type == LV_SUBJECT_TYPE_INT) {
+        lv_subject_set_int(subject, lv_slider_get_value(slider));
+    }
+#if LV_USE_FLOAT
+    else {
+        lv_subject_set_float(subject, (float)lv_slider_get_value(slider));
+    }
+#endif
+}
+
+static void slider_value_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    if(subject->type == LV_SUBJECT_TYPE_INT) {
+        lv_slider_set_value(observer->target, subject->value.num, LV_ANIM_OFF);
+    }
+#if LV_USE_FLOAT
+    else {
+        lv_slider_set_value(observer->target, (int32_t)subject->value.float_v, LV_ANIM_OFF);
+    }
+#endif
+}
+
+#endif /*LV_USE_OBSERVER*/
+
+
 #endif
diff --git a/src/widgets/slider/lv_slider.h b/src/widgets/slider/lv_slider.h
index 90e68d251e..dee05ceb00 100644
--- a/src/widgets/slider/lv_slider.h
+++ b/src/widgets/slider/lv_slider.h
@@ -183,6 +183,17 @@ lv_slider_orientation_t lv_slider_get_orientation(lv_obj_t * slider);
 */
 bool lv_slider_is_symmetrical(lv_obj_t * obj);
 
+
+#if LV_USE_OBSERVER
+/**
+ * Bind an integer Subject to a Slider's value.
+ * @param obj       pointer to Slider
+ * @param subject   pointer to Subject
+ * @return          pointer to newly-created Observer
+ */
+lv_observer_t * lv_slider_bind_value(lv_obj_t * obj, lv_subject_t * subject);
+#endif
+
 /**********************
  *      MACROS
  **********************/
diff --git a/src/widgets/span/lv_span.c b/src/widgets/span/lv_span.c
index 1f0dfa584d..554ac3f7b2 100644
--- a/src/widgets/span/lv_span.c
+++ b/src/widgets/span/lv_span.c
@@ -16,6 +16,7 @@
 #include "../../misc/lv_assert.h"
 #include "../../misc/lv_text_private.h"
 #include "../../misc/lv_bidi_private.h"
+#include "../../others/observer/lv_observer_private.h"
 #include "../../misc/lv_text_ap.h"
 #include "../../core/lv_global.h"
 
@@ -43,6 +44,11 @@ struct _snippet_stack {
     uint32_t        index;
 };
 
+typedef struct {
+    lv_subject_t * subject;
+    void * element; /**< span of a span group*/
+    const char * fmt;
+} bind_element_string_t;
 /**********************
  *  STATIC PROTOTYPES
  **********************/
@@ -71,6 +77,9 @@ static int32_t convert_indent_pct(lv_obj_t * spans, int32_t width);
 
 static lv_span_coords_t make_span_coords(const lv_span_t * prev_span, const lv_span_t * curr_span, int32_t width,
                                          lv_area_t padding, int32_t indent);
+#if LV_USE_OBSERVER
+    static void span_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
+#endif
 
 /**********************
  *  STATIC VARIABLES
@@ -729,6 +738,54 @@ void lv_spangroup_refresh(lv_obj_t * obj)
     lv_obj_refresh_self_size(obj);
 }
 
+#if LV_USE_OBSERVER
+lv_observer_t * lv_spangroup_bind_span_text(lv_obj_t * obj, lv_span_t * span, lv_subject_t * subject, const char * fmt)
+{
+    LV_ASSERT_NULL(subject);
+    LV_ASSERT_NULL(obj);
+    LV_ASSERT_NULL(span);
+
+    if(fmt == NULL) {
+        if(subject->type == LV_SUBJECT_TYPE_INT) {
+            fmt = "%d";
+        }
+#if LV_USE_FLOAT
+        else if(subject->type == LV_SUBJECT_TYPE_FLOAT) {
+            fmt = "%0.1f";
+        }
+#endif
+        else if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER) {
+            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+            return NULL;
+        }
+    }
+    else {
+        if(subject->type != LV_SUBJECT_TYPE_STRING && subject->type != LV_SUBJECT_TYPE_POINTER &&
+           subject->type != LV_SUBJECT_TYPE_INT && subject->type != LV_SUBJECT_TYPE_FLOAT) {
+            LV_LOG_WARN("Incompatible subject type: %d", subject->type);
+            return NULL;
+        }
+    }
+
+    bind_element_string_t * user_data = lv_zalloc(sizeof(bind_element_string_t));
+    if(user_data == NULL) {
+        LV_LOG_WARN("Couldn't allocate user_data");
+        LV_ASSERT_MALLOC(user_data);
+        return NULL;
+    }
+
+    user_data->subject = subject;
+    user_data->element = span;
+    user_data->fmt = fmt;
+
+    lv_observer_t * observer = lv_subject_add_observer_obj(subject, span_text_observer_cb, obj, user_data);
+    observer->auto_free_user_data = 1;
+
+    return observer;
+}
+#endif /*LV_USE_OBSERVER*/
+
+
 /**********************
  *   STATIC FUNCTIONS
  **********************/
@@ -1398,4 +1455,36 @@ static lv_span_coords_t make_span_coords(const lv_span_t * prev_span, const lv_s
     return coords;
 }
 
+#if LV_USE_OBSERVER
+
+static void span_text_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
+{
+    bind_element_string_t * user_data = observer->user_data;
+
+    if(user_data->fmt == NULL) {
+        lv_spangroup_set_span_text(observer->target, user_data->element, subject->value.pointer);
+    }
+    else {
+        switch(subject->type) {
+
+            case LV_SUBJECT_TYPE_INT:
+                lv_spangroup_set_span_text_fmt(observer->target, user_data->element, user_data->fmt, subject->value.num);
+                break;
+#if LV_USE_FLOAT
+            case LV_SUBJECT_TYPE_FLOAT:
+                lv_spangroup_set_span_text_fmt(observer->target, user_data->element, user_data->fmt, subject->value.float_v);
+                break;
+#endif
+            case LV_SUBJECT_TYPE_STRING:
+            case LV_SUBJECT_TYPE_POINTER:
+                lv_spangroup_set_span_text_fmt(observer->target, user_data->element, user_data->fmt, subject->value.pointer);
+                break;
+            default:
+                return;
+        }
+    }
+}
+
+#endif /*LV_USE_OBSERVER*/
+
 #endif
diff --git a/src/widgets/span/lv_span.h b/src/widgets/span/lv_span.h
index 95f1599bbe..8e37b09087 100644
--- a/src/widgets/span/lv_span.h
+++ b/src/widgets/span/lv_span.h
@@ -15,6 +15,7 @@ extern "C" {
  *********************/
 #include "../../lv_conf_internal.h"
 #include "../../core/lv_obj.h"
+#include "../../others/observer/lv_observer.h"
 
 #if LV_USE_SPAN != 0
 
@@ -334,6 +335,24 @@ lv_span_t * lv_spangroup_get_span_by_point(lv_obj_t * obj, const lv_point_t * po
  */
 void lv_spangroup_refresh(lv_obj_t * obj);
 
+#if LV_USE_OBSERVER
+
+/**
+ * Bind an integer, string, or pointer Subject to a Spangroup's Span.
+ * @param obj       pointer to Spangroup
+ * @param span      pointer to Span
+ * @param subject   pointer to Subject
+ * @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
+ */
+lv_observer_t * lv_spangroup_bind_span_text(lv_obj_t * obj, lv_span_t * span, lv_subject_t * subject, const char * fmt);
+
+#endif
+
 /**********************
  *      MACROS
  **********************/