implement fading

things/DeviceLed.cpp

@@ -61,12 +61,70 @@ bool DeviceLed::ledColorHandler(String message) {
   return true;
 }
 
+bool DeviceLed::ledFadeHandler(String message) {
+  DynamicJsonBuffer json_inBuffer;
+  JsonObject& json_in = json_inBuffer.parseObject(message);
+  if (json_in.success()) {
+    fade_from_red = led_red;
+    if (json_in.containsKey("red")) {
+      fade_to_red = json_in["red"];
+    } else {
+      fade_to_red = led_red;
+    }
+    fade_from_green = led_green;
+    if (json_in.containsKey("green")) {
+      fade_to_green = json_in["green"];
+    } else {
+      fade_to_green = led_green;
+    }
+    fade_from_blue = led_blue;
+    if (json_in.containsKey("blue")) {
+      fade_to_blue = json_in["blue"];
+    } else {
+      fade_to_blue = led_blue;
+    }
+    fade_start = millis();
+    if (json_in.containsKey("seconds")) {
+      fade_end = fade_start + 1000 * (int)json_in["seconds"];
+    } else {
+      fade_end = 0;
+    }
+    fading = true;
+  } else {
+    Serial.println("parsing of JSON failed");
+  }
+  return true;
+}
+
 void DeviceLed::deviceRegister() {
   ledNode.subscribe("on", [this](String value) { return ledOnHandler(value); });
   ledNode.subscribe("color", [this](String value) { return ledColorHandler(value); });
+  ledNode.subscribe("fade", [this](String value) { return ledFadeHandler(value); });
   Homie.registerNode(ledNode);
 }
 
 void DeviceLed::deviceLoop() {
+  if (fading) {
+    if (fade_end > millis()) {
+      float progress = 1.0 * (millis() - fade_start) / (fade_end - fade_start);
+      if ((int)(progress * 100) != (int)(progress_last * 100)) {
+        led_red = fade_from_red + (fade_to_red - fade_from_red) * progress;
+        analogWrite(pinRed, led_red);
+        led_green = fade_from_green + (fade_to_green - fade_from_green) * progress;
+        analogWrite(pinGreen, led_green);
+        led_blue = fade_from_blue + (fade_to_blue - fade_from_blue) * progress;
+        analogWrite(pinBlue, led_blue);
+        progress_last = progress;
+      }
+    } else {
+        led_red = fade_to_red;
+        analogWrite(pinRed, led_red);
+        led_green = fade_to_green;
+        analogWrite(pinGreen, led_green);
+        led_blue = fade_to_blue;
+        analogWrite(pinBlue, led_blue);
+      fading = false;
+    }
+  }
   return;
 }

things/DeviceLed.h

@@ -20,7 +20,15 @@ class DeviceLed : public Device {
     int led_red = 0;
     int led_green = 0;
     int led_blue = 0;
+    bool fading = false;
+    int fade_from_red, fade_to_red;
+    int fade_from_green, fade_to_green;
+    int fade_from_blue, fade_to_blue;
+    unsigned long fade_start = 0;
+    unsigned long fade_end = 0;
+    float progress_last = 0;
     bool ledOnHandler(String value);
     bool ledColorHandler(String message);
+    bool ledFadeHandler(String message);
     HomieNode ledNode{"led", "rgb"};
 };