Added first code for Wifi and MQTT

Abstandssensor.ino

@@ -1,13 +1,21 @@
+#include <WiFi.h>
+
 #include <NeoPixelBus.h>
 #include <NeoPixelSegmentBus.h>
 #include <NeoPixelAnimator.h>
 #include <NeoPixelBrightnessBus.h>
 
+#include <MQTTPubSubClient.h>
+
+#include "config.h"
+
 // Only for ESP8266 D1 Mini
 #define ECHO 5      // D1
 #define TRIG 16     // D0
 #define POTI_IN 17  // A0, analog In
 
+WiFiClient client;
+MQTTPubSubClient mqtt;
 
 // Set Data pin for LED ring (we use GPIO3, which is also RX of the serial line)
 #define DATA_PIN 3
@@ -32,6 +40,21 @@ RgbColor black(0);
 
 void setup() {
 
+    // start your network
+    WiFi.begin(wifi_ssid, wifi_password);
+    // connect to host
+    client.connect(mqtt_server, 1883);
+    // initialize mqtt client
+    mqtt.begin(client);
+    // connect to mqtt broker
+    mqtt.connect("arduino", "public", "public");
+
+    // subscribe topic and callback which is called when /hello has come
+    mqtt.subscribe("/hello", [](const String& payload, const size_t size) {
+        Serial.print("/hello ");
+        Serial.println(payload);
+    });
+
   // Setup the ultrasonic sensor PIN
   pinMode(TRIG, OUTPUT);  // TRIG-Pin: Output
   pinMode(ECHO, INPUT);   // ECHO-Pin: Input

config.h

@@ -0,0 +1,4 @@
+      char* wifi_ssid        = "your-ssid";
+      char* wifi_password    = "your-passwd";
+const char* mqtt_server = "your.mqtt.broker.org";
+const char* mqtt_topic  = "/your/topic/to/listen/to";