initial w5500 support

networkDevices/NetworkDevice.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "PubSubClient.h"
+
+class NetworkDevice
+{
+public:
+    explicit NetworkDevice(const String& hostname)
+    : _hostname(hostname)
+    {}
+
+    virtual PubSubClient* mqttClient() = 0;
+
+    virtual void initialize() = 0;
+    virtual void reconfigure() = 0;
+
+    virtual bool isConnected() = 0;
+
+protected:
+    const String _hostname;
+};