====== Klingeldetektor ======

<note>Zurzeit ist die Funkbrücke in die E-Werkstatt und den Kreativraum außer Betrieb! Auch wird die Torklingel zurzeit überarbeitet!</note>

Es wird unsere Telegram Gruppe gepostet sobald geklingelt wurde.

{{:sonstiges:photo_2026-04-20_02-48-38.jpg?400|}}

[[https://schuballaa.hackerspace-bremen.de/telegram.php|HSHB Telegram Gruppe]]

{{:sonstiges:photo_2026-04-19_21-24-52.jpg?400|}}

Der Klingeldetektor erkennt, ob an der Tür oder am Tor geklingelt wurde.
===== Erkennungswege =====

  * **Tür:** Auswertung des Datenbusses des hauseigenen Klingelsystems (**QwikBus**)
  * **Tor:** Erkennung über **LDR (Lichtsensor)** am Empfänger der Torklingel

===== Bei einem Klingelereignis =====

  * LED-Visualisierung Ort (**Tor / Tür**)
  * Akustische und visuelle Anzeige im Hauptraum
  * Klingelsignal weitergabe an **E-Werkstatt** und **Kreativwerkstatt** (über eine **Funkbrücke**)
  * Meldung an Telegram ([[https://t.me/joinchat/OwmGe1WZmRs1ZDJi|Gruppe]])
  * Meldung per **MQTT** im Hackerspace-System (für zukünftige Erweiterungen)

===== Verhalten im Standby =====

  * Warten auf ein Klingelereignis
  * LEDs werden ein- und ausgeblendet, um Standby und Funktionsbereitschaft zu visualisieren


===== Umgesetzte Extras =====

  * MQTT-Integration
  * Akustische und visuelle Anzeige im Hauptraum
  * Funkverteilung in die anderen Räume
  * LED-Visualisierung (Tor / Bornstraße)

===== Danksagungen: =====

  * **Marco** – Tips bei der Entwicklung der Hardware
  * **Delpiño** – Unterstützung beim Auswertendes Datenbusses
  * **Markus** – Idee zur LED-Visualisierung (Tor / Bornstraße)
===== Technische Erklärung =====

{{:sonstiges:photo_2026-04-04_01-50-41.jpg?400|}}
==== Tür – QwikBus-Auswertung ====

Das hauseigene Klingelsystem (QwikBus) überträgt Klingelereignisse als zeitkodierte elektrische Signale.

**Signalcharakteristik:**
  * Ruhespannung: ca. ~20 V
  * Aktivsignal: ca. ~18 V
  * Information in **zeitlichen Pulsfolgen**

**Hardware:**
  * 1 nF um nur die Busänderungen zu dedektieren
  * Spannungsteiler
  * Schmitt-Trigger
  * Mikrocontroller (ESP32)

**Verarbeitung:**
  * Flankenerkennung (Interrupt)
  * Zeitmessung im µs-Bereich
  * Bildung von Sequenzen:
  * Quantisierung zur Reduktion von Rauschen
  * Mustervergleich (Pattern Matching) zur Klassifikation

**Ergebnis:**
  * Zuordnung des Signals zu einem **Türklingel-Ereignis**

==== Tor – LDR-Auswertung ====

Das Torklingeln wird über das optische Signal des Empfängers erkannt.

**Signalquelle:**
  * Blinkende LED am Empfänger der Torklingel

**Hardware:**
  * LDR (Lichtsensor)
  * Widerstand als Spannungsteiler
  * ADC-Eingang am Mikrocontroller

**Verarbeitung:**
  * Kontinuierliche Helligkeitsmessung
  * Schwellwertbasierte Erkennung (Hell/Dunkel)
  * Zeitliche Analyse des Blinkmusters
  * Entprellung zur Vermeidung von Fehltriggern

**Ergebnis:**
  * Zuordnung des Signals zu einem **Torklingel-Ereignis**

----

==== Ereignisverarbeitung ====

Nach der Erkennung erfolgt die weitere Verarbeitung:

  * Klassifikation: **Tür** oder **Tor**
  * Generierung eines Events
  * Veröffentlichung per **MQTT** im Hackerspace-System
  * Ansteuerung der **LED-Visualisierung (Tor / Bornstraße)**
  * Weitergabe der Information:
    * Akustisch und visuell im **Hauptraum**
    * Über **Funkbrücke** an **E-Werkstatt** und **Kreativwerkstatt**
{{:sonstiges:pxl_20260415_1832213091.jpg?400|}}
{{:sonstiges:mqtt.png?400|}}
{{:sonstiges:torsensor.jpg?400|}}
{{:sonstiges:photo_2026-04-04_01-50-57.jpg?400|}}

==== Code ====

<code>

#include <WiFi.h>
#include <esp_wifi.h>
#include <PubSubClient.h>
#include <time.h>
#include <Preferences.h>
#include <WebServer.h>
#include <HTTPUpdateServer.h>
#include <ArduinoOTA.h>
#include <ESPmDNS.h>
#include <Arduino.h>
#include <cstring>
#include "esp32-hal-rmt.h"
#include <math.h>

// =====================================================
// WLAN / MQTT
// =====================================================
const char* WIFI_SSID     = "Hackerspace";
const char* WIFI_PASSWORD = "****";

const char* MQTT_HOST = "daniel-stingl.de";
const int   MQTT_PORT = ****;
const char* MQTT_USER = "***";
const char* MQTT_PASS = "***";

const char* MQTT_TOPIC_TUER      = "/hshb/status/klingel/tuer";
const char* MQTT_TOPIC_TOR       = "/hshb/status/klingel/tor";
const char* MQTT_TOPIC_STATUS    = "/hshb/status/klingel/status";
const char* MQTT_TOPIC_TUER_TEST = "/hshb/status/klingel/tuertest";
const char* MQTT_TOPIC_TOR_TEST  = "/hshb/status/klingel/tortest";

// =====================================================
// OTA / Web
// =====================================================
const char* OTA_HOSTNAME = "hshb-klingel";
const char* OTA_USER     = "****";
const char* OTA_PASS     = "****";

// =====================================================
// NTP
// =====================================================
const char* NTP_SERVER = "pool.ntp.org";
const long  GMT_OFFSET_SEC = 3600;
const int   DAYLIGHT_OFFSET_SEC = 3600;

// =====================================================
// MAC
// =====================================================
uint8_t newMACAddress[] = {0x30, 0xAF, 0xA0, 0x05, 0x1D, 0x63};

// =====================================================
// Pins
// =====================================================
constexpr int bellPin    = 5;   // Trigger-Ausgang
constexpr int busPin     = 32;  // RMT RX
const int adcTorPin      = 33;  // ADC
const int testBellPin    = 26;  // Taster

// =====================================================
// RMT / Nachrichten
// =====================================================
constexpr uint8_t hackerspaceBell[]  = {0x25, 0x2E, 0xC4, 0x00, 0xE8};
constexpr uint8_t hackerspaceBell2[] = {0x25, 0x2E, 0xE2, 0x00, 0xCA};

constexpr size_t bufferSize = 16;
constexpr size_t maxSyms = RMT_MEM_NUM_BLOCKS_2 * RMT_SYMBOLS_PER_CHANNEL_BLOCK;

rmt_data_t symbols[maxSyms];
size_t symbolCount = maxSyms;

enum { P_BAD = -1, P_ZERO = 0, P_ONE = 1, P_START = 2, P_STOP = 3 };

// =====================================================
// Zeiten / Zustände
// =====================================================
unsigned long lastBellTriggered       = 0;
unsigned long lastTorTriggerMillis    = 0;
unsigned long lastButtonTriggerMillis = 0;
unsigned long lastDebugMillis         = 0;
unsigned long lastStatusMillis        = 0;
unsigned long bellPulseStartMillis    = 0;
unsigned long lastWifiReconnectMs     = 0;
unsigned long lastMqttReconnectMs     = 0;
unsigned long lastNtpSyncMs           = 0;

const unsigned long BellDebounceMs     = 300;
const unsigned long TorDebounceMs      = 11000;
const unsigned long ButtonDebounceMs   = 300;
const unsigned long Debuginterval      = 1000;
const unsigned long StatusMs           = 5000;
const unsigned long BellPulseMs        = 10;
const unsigned long WifiRetryMs        = 10000;
const unsigned long MqttRetryMs        = 5000;
const unsigned long NtpResyncMs        = 6UL * 60UL * 60UL * 1000UL;
const unsigned long LedEventDurationMs = 60000;  // 60 Sekunden

const int adcTorThreshold = 1500;

bool bellPulseActive = false;
bool timeValid = false;
bool lastButtonState = HIGH;
bool lastTorState = false;

String lastState = "IDLE";
String lastSource = "-";
String lastDecodedHex = "-";
uint32_t lastDecodedLen = 0;
int adcTorValue = 0;

// =========================
// LEDs
// =========================
const int ledTuerPin = 23;
const int ledTorPin  = 19;

const int ledFreq = 5000;
const int ledResolution = 8;

enum LedMode {
  LED_MODE_STANDBY,
  LED_MODE_SHOW_TUER,
  LED_MODE_SHOW_TOR
};

LedMode ledMode = LED_MODE_STANDBY;
unsigned long ledModeUntilMs = 0;
unsigned long lastLedUpdateMs = 0;
unsigned long lastBlinkToggleMs = 0;
bool ledBlinkState = false;

// =====================================================
// Objekte
// =====================================================
WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);
Preferences preferences;
WebServer httpServer(80);
HTTPUpdateServer httpUpdater;

// =====================================================
// Vorwärtsdeklarationen
// =====================================================
bool connectWiFi();
bool ensureMqttConnected();
bool syncTime();
bool ensureTimeValid();
bool publishUnixTimeToTopic(const char* topic);
bool publishStatus();
void markMqttPendingTuer();
void markMqttPendingTor();
bool isMqttPendingTuer();
bool isMqttPendingTor();
void clearMqttPendingTuer();
void clearMqttPendingTor();
void processPendingMqtt();
void setupHttpRoutes();
void setupArduinoOta();
void triggerBell(bool fromButton);
void triggerTorEvent(const char* source);
void mqttCallback(char* topic, byte* payload, unsigned int length);
String buildDebugJson();

int pulseType(uint16_t us);
size_t collectLows(const rmt_data_t *symbols, size_t symbolCount, uint16_t *lows);
int decodeByte(const uint16_t *pulses);
bool decodeMessage(const rmt_data_t *symbols, size_t symbolCount, uint8_t *msg, size_t &len);
bool messageContains(const uint8_t *msg, size_t len, const uint8_t *what, size_t whatLen);

// =====================================================
// WLAN / Zeit / MQTT
// =====================================================
bool connectWiFi() {
  if (WiFi.status() == WL_CONNECTED) return true;

  unsigned long now = millis();
  if (now - lastWifiReconnectMs < WifiRetryMs) return false;
  lastWifiReconnectMs = now;

  Serial.println("Verbinde mit WLAN...");
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

  unsigned long startAttemptTime = millis();
  while (WiFi.status() != WL_CONNECTED && millis() - startAttemptTime < 10000) {
    delay(250);
    Serial.print(".");
  }
  Serial.println();

  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("WLAN verbunden");
    Serial.print("IP: ");
    Serial.println(WiFi.localIP());
    return true;
  }

  Serial.println("WLAN Verbindung fehlgeschlagen");
  return false;
}

bool syncTime() {
  if (WiFi.status() != WL_CONNECTED) return false;

  Serial.println("Synchronisiere Zeit per NTP...");
  configTime(GMT_OFFSET_SEC, DAYLIGHT_OFFSET_SEC, NTP_SERVER);

  time_t now = time(nullptr);
  int retry = 0;

  while (now < 100000 && retry < 20) {
    delay(500);
    Serial.print(".");
    now = time(nullptr);
    retry++;
  }
  Serial.println();

  if (now < 100000) {
    Serial.println("NTP Zeit konnte nicht geholt werden");
    timeValid = false;
    return false;
  }

  Serial.print("Aktuelle Unix-Zeit: ");
  Serial.println((unsigned long)now);
  lastNtpSyncMs = millis();
  timeValid = true;
  return true;
}

bool ensureTimeValid() {
  time_t now = time(nullptr);
  if (now > 100000 && timeValid) {
    if (millis() - lastNtpSyncMs < NtpResyncMs) {
      return true;
    }
  }
  return syncTime();
}

bool ensureMqttConnected() {
  mqttClient.setServer(MQTT_HOST, MQTT_PORT);

  if (mqttClient.connected()) return true;
  if (WiFi.status() != WL_CONNECTED) return false;

  unsigned long now = millis();
  if (now - lastMqttReconnectMs < MqttRetryMs) return false;
  lastMqttReconnectMs = now;

  String clientId = "esp32-klingel-";
  clientId += String((uint32_t)ESP.getEfuseMac(), HEX);

  Serial.println("Verbinde MQTT...");
  if (mqttClient.connect(clientId.c_str(), MQTT_USER, MQTT_PASS)) {
    Serial.println("MQTT verbunden");

    mqttClient.subscribe(MQTT_TOPIC_TUER_TEST);
    mqttClient.subscribe(MQTT_TOPIC_TOR_TEST);
    Serial.println("MQTT Test-Topics subscribed");

    return true;
  }

  Serial.print("MQTT Verbindung fehlgeschlagen, rc=");
  Serial.println(mqttClient.state());
  return false;
}

bool publishUnixTimeToTopic(const char* topic) {
  if (!connectWiFi()) return false;
  if (!ensureTimeValid()) return false;
  if (!ensureMqttConnected()) return false;

  time_t now = time(nullptr);
  uint64_t nowMs = ((uint64_t)now) * 1000ULL + (millis() % 1000ULL);

  char payload[32];
  snprintf(payload, sizeof(payload), "%llu", (unsigned long long)nowMs);

  bool ok = mqttClient.publish(topic, payload, true);

  if (ok) {
    Serial.print("MQTT gesendet an ");
    Serial.print(topic);
    Serial.print(" mit Payload: ");
    Serial.println(payload);
  } else {
    Serial.print("MQTT publish fehlgeschlagen für ");
    Serial.println(topic);
  }

  mqttClient.loop();
  return ok;
}

void updateLeds() {
  unsigned long now = millis();

  if (ledMode != LED_MODE_STANDBY && (long)(now - ledModeUntilMs) >= 0) {
    ledMode = LED_MODE_STANDBY;
  }

  // ===== Langsames sinusförmiges Fade im Standby =====
  if (ledMode == LED_MODE_STANDBY) {
    if (now - lastLedUpdateMs >= 25) {
      lastLedUpdateMs = now;

      static float phase = 0.0f;

      // kleiner = langsamer
      phase += 0.02f;

      if (phase > 2.0f * PI) {
        phase -= 2.0f * PI;
      }

      int brightness = (int)((sin(phase) * 0.5f + 0.5f) * 255.0f);

      ledcWrite(ledTuerPin, brightness);
      ledcWrite(ledTorPin, brightness);
    }
    return;
  }

  // ===== Event-Blinken =====
  if (now - lastBlinkToggleMs >= 100) {
    lastBlinkToggleMs = now;
    ledBlinkState = !ledBlinkState;
  }

  if (ledMode == LED_MODE_SHOW_TUER) {
    ledcWrite(ledTuerPin, ledBlinkState ? 255 : 0);
    ledcWrite(ledTorPin, 255);
    return;
  }

  if (ledMode == LED_MODE_SHOW_TOR) {
    ledcWrite(ledTuerPin, 255);
    ledcWrite(ledTorPin, ledBlinkState ? 255 : 0);
    return;
  }
}

bool publishStatus() {
  if (!connectWiFi()) return false;
  if (!ensureMqttConnected()) return false;

  String json = buildDebugJson();
  bool ok = mqttClient.publish(MQTT_TOPIC_STATUS, json.c_str(), true);

  if (ok) {
    Serial.println("MQTT Status (JSON) gesendet");
  } else {
    Serial.println("MQTT Status publish fehlgeschlagen");
  }

  mqttClient.loop();
  return ok;
}

// =====================================================
// Pending Flags
// =====================================================
bool isMqttPendingTuer() {
  preferences.begin("klingel", true);
  bool pending = preferences.getBool("mqttTuer", false);
  preferences.end();
  return pending;
}

bool isMqttPendingTor() {
  preferences.begin("klingel", true);
  bool pending = preferences.getBool("mqttTor", false);
  preferences.end();
  return pending;
}

void clearMqttPendingTuer() {
  preferences.begin("klingel", false);
  preferences.putBool("mqttTuer", false);
  preferences.end();
}

void clearMqttPendingTor() {
  preferences.begin("klingel", false);
  preferences.putBool("mqttTor", false);
  preferences.end();
}

void markMqttPendingTuer() {
  preferences.begin("klingel", false);
  preferences.putBool("mqttTuer", true);
  preferences.end();
}

void markMqttPendingTor() {
  preferences.begin("klingel", false);
  preferences.putBool("mqttTor", true);
  preferences.end();
}

void processPendingMqtt() {
  if (isMqttPendingTuer()) {
    if (publishUnixTimeToTopic(MQTT_TOPIC_TUER)) {
      clearMqttPendingTuer();
    }
  }

  if (isMqttPendingTor()) {
    if (publishUnixTimeToTopic(MQTT_TOPIC_TOR)) {
      clearMqttPendingTor();
    }
  }
}

// =====================================================
// Web / Debug / OTA
// =====================================================
String buildDebugJson() {
  String json;
  json.reserve(1700);

  json += "{";
  json += "\"wifi\":\"";
  json += (WiFi.status() == WL_CONNECTED ? "connected" : "disconnected");
  json += "\",";
  json += "\"ip\":\"";
  json += WiFi.localIP().toString();
  json += "\",";
  json += "\"rssi\":";
  json += WiFi.RSSI();
  json += ",";
  json += "\"uptime\":";
  json += millis() / 1000UL;
  json += ",";
  json += "\"free_heap\":";
  json += ESP.getFreeHeap();
  json += ",";
  json += "\"state\":\"";
  json += lastState;
  json += "\",";
  json += "\"source\":\"";
  json += lastSource;
  json += "\",";
  json += "\"adcTorValue\":";
  json += adcTorValue;
  json += ",";
  json += "\"adcTorThreshold\":";
  json += adcTorThreshold;
  json += ",";
  json += "\"lastTorState\":";
  json += (lastTorState ? "true" : "false");
  json += ",";
  json += "\"lastDecodedLen\":";
  json += lastDecodedLen;
  json += ",";
  json += "\"lastDecodedHex\":\"";
  json += lastDecodedHex;
  json += "\",";
  json += "\"mqttPendingTuer\":";
  json += (isMqttPendingTuer() ? "true" : "false");
  json += ",";
  json += "\"mqttPendingTor\":";
  json += (isMqttPendingTor() ? "true" : "false");
  json += ",";
  json += "\"bellPulseActive\":";
  json += (bellPulseActive ? "true" : "false");
  json += ",";
  json += "\"hostname\":\"";
  json += OTA_HOSTNAME;
  json += "\",";
  json += "\"mac\":\"";
  json += WiFi.macAddress();
  json += "\"";
  json += "}";

  return json;
}

void setupHttpRoutes() {
  httpServer.on("/", HTTP_GET, []() {
    String html;
    html.reserve(3200);

    html += "<!doctype html><html><head><meta charset='utf-8'>";
    html += "<meta name='viewport' content='width=device-width,initial-scale=1'>";
    html += "<title>HSHB Klingel</title></head><body>";
    html += "<h1>HSHB Klingel</h1>";
    html += "<p><b>IP:</b> " + WiFi.localIP().toString() + "</p>";
    html += "<p><b>RSSI:</b> " + String(WiFi.RSSI()) + "</p>";
    html += "<p><b>Uptime:</b> " + String(millis() / 1000UL) + " s</p>";
    html += "<p><b>State:</b> " + lastState + "</p>";
    html += "<p><b>Source:</b> " + lastSource + "</p>";
    html += "<p><b>ADC Tor:</b> " + String(adcTorValue) + "</p>";
    html += "<p><b>ADC Threshold:</b> " + String(adcTorThreshold) + "</p>";
    html += "<p><b>Last Tor State:</b> " + String(lastTorState ? "true" : "false") + "</p>";
    html += "<p><b>Decoded Len:</b> " + String(lastDecodedLen) + "</p>";
    html += "<p><b>Decoded Hex:</b> " + lastDecodedHex + "</p>";
    html += "<p><b>MQTT pending Tür:</b> " + String(isMqttPendingTuer() ? "true" : "false") + "</p>";
    html += "<p><b>MQTT pending Tor:</b> " + String(isMqttPendingTor() ? "true" : "false") + "</p>";
    html += "<p><b>Bell Pulse:</b> " + String(bellPulseActive ? "true" : "false") + "</p>";
    html += "<p><b>MAC:</b> " + WiFi.macAddress() + "</p>";
    html += "<p><a href='/debug'>Debug JSON</a></p>";
    html += "<p><a href='/update'>Firmware Update</a></p>";
    html += "</body></html>";

    httpServer.send(200, "text/html", html);
  });

  httpServer.on("/debug", HTTP_GET, []() {
    httpServer.send(200, "application/json", buildDebugJson());
  });

  httpUpdater.setup(&httpServer, "/update", OTA_USER, OTA_PASS);
  httpServer.begin();
}

void setupArduinoOta() {
  ArduinoOTA.setHostname(OTA_HOSTNAME);
  ArduinoOTA.setPassword(OTA_PASS);
  ArduinoOTA.begin();
}

// =====================================================
// MQTT Callback
// =====================================================
void mqttCallback(char* topic, byte* payload, unsigned int length) {
  String topicStr = String(topic);
  String payloadStr;

  for (unsigned int i = 0; i < length; i++) {
    payloadStr += (char)payload[i];
  }

  payloadStr.trim();

  Serial.print("MQTT empfangen | topic=");
  Serial.print(topicStr);
  Serial.print(" | payload=");
  Serial.println(payloadStr);

  if (payloadStr != "test") return;

  if (topicStr == MQTT_TOPIC_TUER_TEST) {
    Serial.println("MQTT TEST -> TUER");
    triggerBell(true);
  } else if (topicStr == MQTT_TOPIC_TOR_TEST) {
    Serial.println("MQTT TEST -> TOR");
    triggerTorEvent("mqtt-test");
  }
}

// =====================================================
// Klingeltrigger
// =====================================================
void triggerBell(bool fromButton) {
  unsigned long now = millis();
  if (now - lastBellTriggered < BellDebounceMs) return;

  Serial.println("Bell Triggered!");

  ledMode = LED_MODE_SHOW_TUER;
  ledModeUntilMs = now + LedEventDurationMs;

  lastBellTriggered = now;

  digitalWrite(bellPin, HIGH);
  bellPulseStartMillis = now;
  bellPulseActive = true;

  lastSource = fromButton ? "button" : "bus";
  lastState  = "BELL";

  markMqttPendingTuer();
  processPendingMqtt();
  publishStatus();
}

void triggerTorEvent(const char* source) {
  unsigned long now = millis();

  if (now - lastTorTriggerMillis < TorDebounceMs) {
    Serial.println("TOR blockiert: 11s Sperre aktiv");
    return;
  }

  lastTorTriggerMillis = now;

  ledMode = LED_MODE_SHOW_TOR;
  ledModeUntilMs = now + LedEventDurationMs;
  lastState = "TOR";
  lastSource = source;

  Serial.print("TOR TRIGGER! source=");
  Serial.println(source);

  markMqttPendingTor();
  processPendingMqtt();
  publishStatus();
}

// =====================================================
// RMT Hilfsfunktionen
// =====================================================
int pulseType(uint16_t us) {
  if (us >= 32  && us <= 52)  return P_ONE;
  if (us >= 103 && us <= 123) return P_ZERO;
  if (us >= 223 && us <= 243) return P_START;
  if (us >= 76  && us <= 96)  return P_STOP;
  return P_BAD;
}

size_t collectLows(const rmt_data_t *symbols, size_t symbolCount, uint16_t *lows) {
  size_t n = 0;

  for (size_t i = 0; i < symbolCount && n < maxSyms; ++i) {
    if (symbols[i].level0 && !symbols[i].level1 &&
        symbols[i].duration0 >= 17 && symbols[i].duration0 <= 33 &&
        symbols[i].duration1) {
      lows[n++] = symbols[i].duration1;
    } else if (!symbols[i].level0 && symbols[i].level1 &&
               symbols[i].duration1 >= 17 && symbols[i].duration1 <= 33 &&
               symbols[i].duration0) {
      lows[n++] = symbols[i].duration0;
    } else if (!symbols[i].level0 && pulseType(symbols[i].duration0) != P_BAD) {
      lows[n++] = symbols[i].duration0;
    } else if (!symbols[i].level1 && pulseType(symbols[i].duration1) != P_BAD) {
      lows[n++] = symbols[i].duration1;
    }
  }

  return n;
}

int decodeByte(const uint16_t *pulses) {
  if (pulseType(pulses[0]) != P_START) return -1;

  uint8_t value = 0;
  for (int i = 0; i < 8; ++i) {
    int bit = pulseType(pulses[i + 1]);
    if (bit < 0 || bit > 1) return -1;
    value |= bit << i;
  }
  return value;
}

bool decodeMessage(const rmt_data_t *symbols, size_t symbolCount, uint8_t *msg, size_t &len) {
  uint16_t lows[maxSyms];
  size_t lowCount = collectLows(symbols, symbolCount, lows);

  len = 0;
  for (size_t i = 0; i + 9 < lowCount && len < bufferSize;) {
    if (pulseType(lows[i]) != P_START) {
      ++i;
      continue;
    }

    int value = decodeByte(lows + i);
    if (value < 0) {
      ++i;
      continue;
    }

    msg[len++] = value;
    i += 10;

    if (i < lowCount && lows[i] >= 76) {
      ++i;
    }
  }

  return len > 0;
}

bool messageContains(const uint8_t *msg, size_t len, const uint8_t *what, size_t whatLen) {
  if (whatLen > len) return false;

  for (size_t i = 0; i + whatLen <= len; ++i) {
    if (!memcmp(msg + i, what, whatLen)) return true;
  }
  return false;
}

// =====================================================
// Setup
// =====================================================
void setup() {
  Serial.begin(115200);
  delay(500);

  ledcAttach(ledTuerPin, ledFreq, ledResolution);
  ledcAttach(ledTorPin, ledFreq, ledResolution);

  ledcWrite(ledTuerPin, 0);
  ledcWrite(ledTorPin, 0);

  pinMode(bellPin, OUTPUT);
  digitalWrite(bellPin, LOW);

  pinMode(testBellPin, INPUT_PULLUP);
  pinMode(adcTorPin, INPUT);

  analogReadResolution(12);
  analogSetPinAttenuation(adcTorPin, ADC_11db);

  WiFi.mode(WIFI_STA);
  esp_wifi_set_mac(WIFI_IF_STA, &newMACAddress[0]);

  mqttClient.setServer(MQTT_HOST, MQTT_PORT);
  mqttClient.setCallback(mqttCallback);
  mqttClient.setBufferSize(2048);
  mqttClient.setKeepAlive(30);
  mqttClient.setSocketTimeout(2);

  connectWiFi();
  ensureTimeValid();
  ensureMqttConnected();

  if (MDNS.begin(OTA_HOSTNAME)) {
    MDNS.addService("http", "tcp", 80);
  }

  setupHttpRoutes();
  setupArduinoOta();

  rmtInit(busPin, RMT_RX_MODE, RMT_MEM_NUM_BLOCKS_2, 1000000);
  rmtSetRxMinThreshold(busPin, 3);
  rmtSetRxMaxThreshold(busPin, 1000);
  rmtReadAsync(busPin, symbols, &symbolCount);

  publishStatus();
}

// =====================================================
// Loop
// =====================================================
void loop() {
  unsigned long now = millis();

  updateLeds();
  connectWiFi();
  ensureMqttConnected();
  mqttClient.loop();

  httpServer.handleClient();
  ArduinoOTA.handle();

  adcTorValue = analogRead(adcTorPin);

  bool currentTorState = (adcTorValue > adcTorThreshold);

  // nur steigende Flanke
  if (!lastTorState && currentTorState) {
    Serial.print("TOR Flanke erkannt, ADC=");
    Serial.println(adcTorValue);
    triggerTorEvent("adc");
  }

  lastTorState = currentTorState;

  bool currentButtonState = digitalRead(testBellPin);
  if (lastButtonState == HIGH && currentButtonState == LOW &&
      (now - lastButtonTriggerMillis > ButtonDebounceMs)) {
    lastButtonTriggerMillis = now;
    triggerBell(true);
  }
  lastButtonState = currentButtonState;

  if (rmtReceiveCompleted(busPin)) {
    uint8_t msg[bufferSize];
    size_t len = 0;

    decodeMessage(symbols, symbolCount, msg, len);

    lastDecodedLen = len;
    lastDecodedHex = "";
    for (size_t i = 0; i < len; ++i) {
      char tmp[4];
      snprintf(tmp, sizeof(tmp), "%02X", msg[i]);
      if (i) lastDecodedHex += " ";
      lastDecodedHex += tmp;
    }
    if (lastDecodedHex.length() == 0) lastDecodedHex = "-";

    symbolCount = maxSyms;
    rmtReadAsync(busPin, symbols, &symbolCount);

    if (messageContains(msg, len, hackerspaceBell, sizeof(hackerspaceBell)) ||
        messageContains(msg, len, hackerspaceBell2, sizeof(hackerspaceBell2))) {
      triggerBell(false);
    }
  }

  if (bellPulseActive && (now - bellPulseStartMillis > BellPulseMs)) {
    digitalWrite(bellPin, LOW);
    bellPulseActive = false;
    if (lastState == "BELL") {
      lastState = "IDLE";
    }
  }

  if (now - lastStatusMillis > StatusMs) {
    lastStatusMillis = now;
    publishStatus();
  }

  if (now - lastDebugMillis > Debuginterval) {
    lastDebugMillis = now;
    Serial.print("state=");
    Serial.print(lastState);
    Serial.print(" source=");
    Serial.print(lastSource);
    Serial.print(" adc=");
    Serial.print(adcTorValue);
    Serial.print(" torState=");
    Serial.println(currentTorState ? "1" : "0");
  }

  delay(1);
}
</code>