From 7a37afe417c4fb6ff0abf45df0bd9a13fe6b66fd Mon Sep 17 00:00:00 2001
From: Marcel Walter <marcel.s.walter@gmail.com>
Date: Fri, 16 Jan 2026 23:16:41 +0100
Subject: [PATCH] MQTT: add Homeassistant discovery message

---
 src/main.cpp | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/src/main.cpp b/src/main.cpp
index 09d9510..9b7ac54 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -44,6 +44,59 @@ void publishClose()
   mqtt.publish(FLIPDOT_TEXT_TOPIC "/state", output);
 }
 
+void publishHomeAssistantDiscovery()
+{
+  auto mac = WiFi.macAddress();
+  mac.replace(":", "_");
+
+  JsonDocument doc;
+
+  JsonObject device = doc["dev"].to<JsonObject>();
+  device["ids"] = mac;
+  device["name"] = "FlipDotDisplay";
+  device["mf"] = "-mf-";
+  device["mdl"] = "-mdl-";
+  device["sw"] = "-sw-";
+  device["sn"] = "-sn-";
+  device["hw"] = "-hw-";
+
+  JsonObject origin = doc["o"].to<JsonObject>();
+  origin["name"] = "Hobbyhimmel";
+  origin["sw"] = "-sw-";
+  origin["url"] = "https://hobbyhimmel.de";
+
+  JsonObject components = doc["cmps"].to<JsonObject>();
+  JsonObject sw = components["FlipDotDisplaySwitch"].to<JsonObject>();
+  sw["unique_id"] = mac + "FlipDotDisplaySwitch";
+  sw["p"] = "switch";
+  sw["command_topic"] = FLIPDOT_SWITCH_TOPIC;
+  sw["state_topic"] = FLIPDOT_SWITCH_TOPIC "/state";
+  sw["payload_on"] = "open";
+  sw["payload_off"] = "close";
+  sw["qos"] = 0;
+  sw["retain"] = false;
+
+  JsonObject txt = components["FlipDotDisplayText"].to<JsonObject>();
+  sw["unique_id"] = mac + "FlipDotDisplayText";
+  sw["p"] = "text";
+  sw["command_topic"] = FLIPDOT_TEXT_TOPIC;
+  sw["state_topic"] = FLIPDOT_TEXT_TOPIC "/state";
+  sw["qos"] = 0;
+  sw["retain"] = false;
+
+  doc["availability_topic "] = FLIPDOT_AVAILABILITY_TOPIC;
+
+  String jsonString;
+  serializeJson(doc, jsonString);
+
+  String discoveryTopic = "homeassistant/device/";
+  discoveryTopic += mac + "/config";
+
+  mqtt.publish(discoveryTopic.c_str(), jsonString.c_str());
+  Serial.print("Homeassistant Discovery was published: ");
+  Serial.println(jsonString);
+}
+
 /* ------------ OTA section and variables -------------- */
 bool OTAStarted;
 void onOTAStart()
@@ -214,6 +267,8 @@ void loop()
         mqtt.subscribe(FLIPDOT_SWITCH_TOPIC);
         mqtt.subscribe(FLIPDOT_TEXT_TOPIC);
         mqtt.publish(FLIPDOT_AVAILABILITY_TOPIC, "available");
+
+        publishHomeAssistantDiscovery();
       }
     }
   }