Update the delta filter to take a percentage value as well as an absolute value (#4391)

esphome/components/sensor/__init__.py

@@ -466,9 +466,21 @@ async def lambda_filter_to_code(config, filter_id):
     return cg.new_Pvariable(filter_id, lambda_)
 
 
-@FILTER_REGISTRY.register("delta", DeltaFilter, cv.float_)
+def validate_delta(config):
+    try:
+        return (cv.positive_float(config), False)
+    except cv.Invalid:
+        pass
+    try:
+        return (cv.percentage(config), True)
+    except cv.Invalid:
+        pass
+    raise cv.Invalid("Delta filter requires a positive number or percentage value.")
+
+
+@FILTER_REGISTRY.register("delta", DeltaFilter, validate_delta)
 async def delta_filter_to_code(config, filter_id):
-    return cg.new_Pvariable(filter_id, config)
+    return cg.new_Pvariable(filter_id, *config)
 
 
 @FILTER_REGISTRY.register("or", OrFilter, validate_filters)

esphome/components/sensor/filter.cpp

@@ -315,19 +315,23 @@ optional<float> ThrottleFilter::new_value(float value) {
 }
 
 // DeltaFilter
-DeltaFilter::DeltaFilter(float min_delta) : min_delta_(min_delta), last_value_(NAN) {}
+DeltaFilter::DeltaFilter(float delta, bool percentage_mode)
+    : delta_(delta), current_delta_(delta), percentage_mode_(percentage_mode), last_value_(NAN) {}
 optional<float> DeltaFilter::new_value(float value) {
   if (std::isnan(value)) {
     if (std::isnan(this->last_value_)) {
       return {};
     } else {
+      if (this->percentage_mode_) {
+        this->current_delta_ = fabsf(value * this->delta_);
+      }
       return this->last_value_ = value;
     }
   }
-  if (std::isnan(this->last_value_)) {
-    return this->last_value_ = value;
+  if (std::isnan(this->last_value_) || fabsf(value - this->last_value_) >= this->current_delta_) {
+    if (this->percentage_mode_) {
+      this->current_delta_ = fabsf(value * this->delta_);
     }
-  if (fabsf(value - this->last_value_) >= this->min_delta_) {
     return this->last_value_ = value;
   }
   return {};

esphome/components/sensor/filter.h

@@ -325,12 +325,14 @@ class HeartbeatFilter : public Filter, public Component {
 
 class DeltaFilter : public Filter {
  public:
-  explicit DeltaFilter(float min_delta);
+  explicit DeltaFilter(float delta, bool percentage_mode);
 
   optional<float> new_value(float value) override;
 
  protected:
-  float min_delta_;
+  float delta_;
+  float current_delta_;
+  bool percentage_mode_;
   float last_value_{NAN};
 };
 

esphome/config_validation.py

@@ -1097,7 +1097,7 @@ def possibly_negative_percentage(value):
     if isinstance(value, str):
         try:
             if value.endswith("%"):
-                has_percent_sign = False
+                has_percent_sign = True
                 value = float(value[:-1].rstrip()) / 100.0
             else:
                 value = float(value)

tests/test1.yaml

@@ -392,6 +392,7 @@ sensor:
       - heartbeat: 5s
       - debounce: 0.1s
       - delta: 5.0
+      - delta: 1%
       - or:
           - throttle: 1s
           - delta: 5.0