[VL53L0X] Add filtering + make threshold more intuitive

src/_P110_VL53L0X.ino

@@ -144,6 +144,9 @@ boolean Plugin_110(uint8_t function, struct EventStruct *event, String& string)
 
       if (nullptr != P110_data) {
         const uint32_t interval_ms = Settings.TaskDeviceTimer[event->TaskIndex] * 1000;
+
+        // Clear the "previous" distance so there will be a new result when starting the task
+        UserVar.setFloat(event->TaskIndex, 3, -1);
         success = P110_data->begin(interval_ms); // Start the sensor
       }
       break;
@@ -153,29 +156,7 @@ boolean Plugin_110(uint8_t function, struct EventStruct *event, String& string)
       P110_data_struct *P110_data = static_cast<P110_data_struct *>(getPluginTaskData(event->TaskIndex));
 
       if (nullptr != P110_data) {
-        if (P110_data->isReadSuccessful()) {
-          const int16_t  dist      = P110_data->getDistance();
-          const int16_t  p_dist    = UserVar.getFloat(event->TaskIndex, 0);
-          // Check trend:
-          //  0 = equal
-          // -1 = move closer
-          //  1 = move away
-          const int16_t  direct    = dist == p_dist ? 0 : (dist < p_dist ? -1 : 1);
-          const bool     triggered = (dist > (p_dist + P110_DELTA)) || (dist < (p_dist - P110_DELTA));
-
-        #ifdef P110_INFO_LOG
-
-          if (loglevelActiveFor(LOG_LEVEL_INFO)) {
-            addLog(LOG_LEVEL_INFO, strformat(F("VL53L0x: Perform read: trig: %d, prev: %d, dist: %d"), triggered, p_dist, dist));
-          }
-        #endif // ifdef P110_INFO_LOG
-
-          if (triggered || (P110_SEND_ALWAYS == 1)) {
-            UserVar.setFloat(event->TaskIndex, 0, dist); // Value is classified as invalid when > 8190, so no conversion or 'split' needed
-            UserVar.setFloat(event->TaskIndex, 1, direct); // Trend of value
-            success = true;
-          }
-        }
+        success = P110_data->plugin_read(event);
       }
       break;
     }
@@ -186,7 +167,7 @@ boolean Plugin_110(uint8_t function, struct EventStruct *event, String& string)
 
       if (nullptr != P110_data) {
         if (P110_data->readDistance() >= 0) {
-          Scheduler.schedule_task_device_timer(event->TaskIndex, millis() + 10);
+          Scheduler.schedule_task_device_timer(event->TaskIndex, millis());
         }
       }
       break;

src/src/PluginStructs/P110_data_struct.cpp

@@ -54,6 +54,55 @@ bool P110_data_struct::plugin_fifty_per_second() {
   return true;
 }
 
+bool P110_data_struct::plugin_read(struct EventStruct *event) {
+  bool success = false;
+
+  if (isReadSuccessful()) {
+    const float new_distance  = getDistance();
+    const float prev_distance = _prev_distance;
+
+    const bool first_sample = (prev_distance < 0.0f);
+
+    const float filtered = first_sample
+            ? new_distance
+            : 0.75f * prev_distance + 0.25f * new_distance;
+
+
+    const float dist   = filtered;
+    const float p_dist = prev_distance;
+
+    // Check trend:
+    //  0 = equal
+    // -1 = move closer
+    //  1 = move away
+
+    const int16_t displacement = first_sample ? 0 : roundf(dist - p_dist);
+    const int16_t disp_dir     = (displacement == 0)
+            ? 0
+            : (displacement > 0) ? 1 : -1;
+
+    const bool direction_changed = disp_dir != static_cast<int16_t>(UserVar.getFloat(event->TaskIndex, 1));
+    const bool triggered         = direction_changed || (std::abs(displacement) > P110_DELTA);
+
+        # ifdef P110_INFO_LOG
+
+    if (loglevelActiveFor(LOG_LEVEL_INFO)) {
+      addLog(LOG_LEVEL_INFO, strformat(F("VL53L0x: Perform read: trig: %d, prev: %d, dist: %d"), triggered, p_dist, dist));
+    }
+        # endif // ifdef P110_INFO_LOG
+    // Value is classified as invalid when > 8190, so no conversion or 'split' needed
+    UserVar.setFloat(event->TaskIndex, 0, filtered);
+    UserVar.setFloat(event->TaskIndex, 1, disp_dir);       // Trend of value
+
+    if (first_sample || triggered || (P110_SEND_ALWAYS == 1)) {
+      // Update the "previous" distance.
+      _prev_distance = filtered;
+      success = true;
+    }
+  }
+  return success;
+}
+
 int16_t P110_data_struct::getDistance() {
   const int res = _distance;
 

src/src/PluginStructs/P110_data_struct.h

@@ -53,10 +53,14 @@ public:
   bool    isReadSuccessful() const;
   bool    plugin_fifty_per_second();
 
+  bool    plugin_read(struct EventStruct *event);
+
 private:
 
   VL53L0X sensor;
 
+  float _prev_distance = -1.0f;
+
   const uint8_t _i2cAddress;
   const int     _timing;
   const bool    _range;

tools/pio/pre_custom_esp32.py

@@ -52,6 +52,7 @@ else:
     "-DUSES_P097",  # Touch (ESP32)
     "-DUSES_P106",  # BME680
     "-DUSES_P107",  # SI1145 UV index
+    "-DUSES_P110",  # VL53L0x
     "-DUSES_P131",  # NeoPixelMatrix
 
     "-DUSES_P146",  # Cache Reader