diff --git a/sma/discovery.cpp b/sma/discovery.cpp
new file mode 100644
index 00000000..fca14ef5
--- /dev/null
+++ b/sma/discovery.cpp
@@ -0,0 +1,271 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+*
+* Copyright 2013 - 2020, nymea GmbH
+* Contact: contact@nymea.io
+*
+* This file is part of nymea.
+* This project including source code and documentation is protected by
+* copyright law, and remains the property of nymea GmbH. All rights, including
+* reproduction, publication, editing and translation, are reserved. The use of
+* this project is subject to the terms of a license agreement to be concluded
+* with nymea GmbH in accordance with the terms of use of nymea GmbH, available
+* under https://nymea.io/license
+*
+* GNU Lesser General Public License Usage
+* Alternatively, this project may be redistributed and/or modified under the
+* terms of the GNU Lesser General Public License as published by the Free
+* Software Foundation; version 3. This project is distributed in the hope that
+* it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public License
+* along with this project. If not, see <https://www.gnu.org/licenses/>.
+*
+* For any further details and any questions please contact us under
+* contact@nymea.io or see our FAQ/Licensing Information on
+* https://nymea.io/license/faq
+*
+* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#include "discovery.h"
+#include "extern-plugininfo.h"
+
+#include <QDebug>
+#include <QXmlStreamReader>
+#include <QNetworkInterface>
+#include <QHostInfo>
+#include <QTimer>
+
+Discovery::Discovery(QObject *parent) : QObject(parent)
+{
+    connect(&m_timeoutTimer, &QTimer::timeout, this, &Discovery::onTimeout);
+}
+
+void Discovery::discoverHosts(int timeout)
+{
+    if (isRunning()) {
+        qWarning(dcSma()) << "Discovery already running. Cannot start twice.";
+        return;
+    }
+    m_timeoutTimer.start(timeout * 1000);
+
+    foreach (const QString &target, getDefaultTargets()) {
+        QProcess *discoveryProcess = new QProcess(this);
+        m_discoveryProcesses.append(discoveryProcess);
+        connect(discoveryProcess, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(discoveryFinished(int,QProcess::ExitStatus)));
+
+        QStringList arguments;
+        arguments << "-oX" << "-" << "-n" << "-sn";
+        arguments << target;
+
+        qCDebug(dcSma()) << "Scanning network:" << "nmap" << arguments.join(" ");
+        discoveryProcess->start(QStringLiteral("nmap"), arguments);
+    }
+
+}
+
+void Discovery::abort()
+{
+    foreach (QProcess *discoveryProcess, m_discoveryProcesses) {
+        if (discoveryProcess->state() == QProcess::Running) {
+            qCDebug(dcSma()) << "Kill running discovery process";
+            discoveryProcess->terminate();
+            discoveryProcess->waitForFinished(5000);
+        }
+    }
+    foreach (QProcess *p, m_pendingArpLookups.keys()) {
+        p->terminate();
+        delete p;
+    }
+    m_pendingArpLookups.clear();
+    m_pendingNameLookups.clear();
+    qDeleteAll(m_scanResults);
+    m_scanResults.clear();
+}
+
+bool Discovery::isRunning() const
+{
+    return !m_discoveryProcesses.isEmpty() || !m_pendingArpLookups.isEmpty() || !m_pendingNameLookups.isEmpty();
+}
+
+void Discovery::discoveryFinished(int exitCode, QProcess::ExitStatus exitStatus)
+{
+    QProcess *discoveryProcess = static_cast<QProcess*>(sender());
+
+    if (exitCode != 0 || exitStatus != QProcess::NormalExit) {
+        qCWarning(dcSma()) << "Nmap error failed. Is nmap installed correctly?";
+        m_discoveryProcesses.removeAll(discoveryProcess);
+        discoveryProcess->deleteLater();
+        discoveryProcess = nullptr;
+        finishDiscovery();
+        return;
+    }
+
+    QByteArray data = discoveryProcess->readAll();
+    m_discoveryProcesses.removeAll(discoveryProcess);
+    discoveryProcess->deleteLater();
+    discoveryProcess = nullptr;
+
+    QXmlStreamReader reader(data);
+
+    int foundHosts = 0;
+
+    while (!reader.atEnd() && !reader.hasError()) {
+        QXmlStreamReader::TokenType token = reader.readNext();
+        if(token == QXmlStreamReader::StartDocument)
+            continue;
+
+        if(token == QXmlStreamReader::StartElement && reader.name() == "host") {
+            bool isUp = false;
+            QString address;
+            QString macAddress;
+            QString vendor;
+            while (!reader.atEnd() && !reader.hasError() && !(token == QXmlStreamReader::EndElement && reader.name() == "host")) {
+                token = reader.readNext();
+
+                if (reader.name() == "address") {
+                    QString addr = reader.attributes().value("addr").toString();
+                    QString type = reader.attributes().value("addrtype").toString();
+                    if (type == "ipv4" && !addr.isEmpty()) {
+                        address = addr;
+                    } else if (type == "mac") {
+                        macAddress = addr;
+                        vendor = reader.attributes().value("vendor").toString();
+                    }
+                }
+
+                if (reader.name() == "status") {
+                    QString state = reader.attributes().value("state").toString();
+                    if (!state.isEmpty())
+                        isUp = state == "up";
+                }
+            }
+
+            if (isUp) {
+                foundHosts++;
+                qCDebug(dcSma()) << "Have host:" << address;
+
+                Host *host = new Host();
+                host->setAddress(address);
+
+                if (!macAddress.isEmpty()) {
+                    host->setMacAddress(macAddress);
+                } else {
+                    QProcess *arpLookup = new QProcess(this);
+                    m_pendingArpLookups.insert(arpLookup, host);
+                    connect(arpLookup, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(arpLookupDone(int,QProcess::ExitStatus)));
+                    arpLookup->start("arp", {"-vn"});
+                }
+
+                host->setHostName(vendor);
+                QHostInfo::lookupHost(address, this, SLOT(hostLookupDone(QHostInfo)));
+                m_pendingNameLookups.insert(address, host);
+
+                m_scanResults.append(host);
+            }
+        }
+    }
+
+    if (foundHosts == 0 && m_discoveryProcesses.isEmpty()) {
+        qCDebug(dcSma()) << "Network scan successful but no hosts found in this network";
+        finishDiscovery();
+    }
+}
+
+void Discovery::hostLookupDone(const QHostInfo &info)
+{
+    Host *host = m_pendingNameLookups.take(info.addresses().first().toString());
+    if (!host) {
+        // Probably aborted...
+        return;
+    }
+    if (info.error() != QHostInfo::NoError) {
+        qWarning(dcSma()) << "Host lookup failed:" << info.errorString();
+    }
+    if (host->hostName().isEmpty() || info.hostName() != host->address()) {
+        host->setHostName(info.hostName());
+    }
+
+    finishDiscovery();
+}
+
+void Discovery::arpLookupDone(int exitCode, QProcess::ExitStatus exitStatus)
+{
+    QProcess *p = static_cast<QProcess*>(sender());
+    p->deleteLater();
+
+    Host *host = m_pendingArpLookups.take(p);
+
+    if (exitCode != 0 || exitStatus != QProcess::NormalExit) {
+        qCWarning(dcSma()) << "ARP lookup process failed for host" << host->address();
+        finishDiscovery();
+        return;
+    }
+
+    QString data = QString::fromLatin1(p->readAll());
+    foreach (QString line, data.split('\n')) {
+        line.replace(QRegExp("[ ]{1,}"), " ");
+        QStringList parts = line.split(" ");
+        if (parts.count() >= 3 && parts.first() == host->address() && parts.at(1) == "ether") {
+            host->setMacAddress(parts.at(2));
+            break;
+        }
+    }
+    finishDiscovery();
+}
+
+void Discovery::onTimeout()
+{
+    qWarning(dcSma()) << "Timeout hit. Stopping discovery";
+    while (!m_discoveryProcesses.isEmpty()) {
+        QProcess *discoveryProcess = m_discoveryProcesses.takeFirst();
+        disconnect(this, SLOT(discoveryFinished(int,QProcess::ExitStatus)));
+        discoveryProcess->terminate();
+        delete discoveryProcess;
+    }
+    foreach (QProcess *p, m_pendingArpLookups.keys()) {
+        p->terminate();
+        m_scanResults.removeAll(m_pendingArpLookups.value(p));
+        delete p;
+    }
+    m_pendingArpLookups.clear();
+    m_pendingNameLookups.clear();
+    finishDiscovery();
+}
+
+QStringList Discovery::getDefaultTargets()
+{
+    QStringList targets;
+    foreach (const QHostAddress &interface, QNetworkInterface::allAddresses()) {
+        if (!interface.isLoopback() && interface.scopeId().isEmpty() && interface.protocol() == QAbstractSocket::IPv4Protocol) {
+            QPair<QHostAddress, int> pair = QHostAddress::parseSubnet(interface.toString() + "/24");
+            QString newTarget = QString("%1/%2").arg(pair.first.toString()).arg(pair.second);
+            if (!targets.contains(newTarget)) {
+                targets.append(newTarget);
+            }
+        }
+    }
+    return targets;
+}
+
+void Discovery::finishDiscovery()
+{
+    if (m_discoveryProcesses.count() > 0 || m_pendingNameLookups.count() > 0 || m_pendingArpLookups.count() > 0) {
+        // Still busy...
+        return;
+    }
+
+    QList<Host> hosts;
+    foreach (Host *host, m_scanResults) {
+        if (!host->macAddress().isEmpty()) {
+            hosts.append(*host);
+        }
+    }
+    qDeleteAll(m_scanResults);
+    m_scanResults.clear();
+
+    qCDebug(dcSma()) << "Emitting thing discovered for" << hosts.count() << "devices";
+    m_timeoutTimer.stop();
+    emit finished(hosts);
+}
diff --git a/sma/discovery.h b/sma/discovery.h
new file mode 100644
index 00000000..b74fe2cb
--- /dev/null
+++ b/sma/discovery.h
@@ -0,0 +1,77 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+*
+* Copyright 2013 - 2020, nymea GmbH
+* Contact: contact@nymea.io
+*
+* This file is part of nymea.
+* This project including source code and documentation is protected by
+* copyright law, and remains the property of nymea GmbH. All rights, including
+* reproduction, publication, editing and translation, are reserved. The use of
+* this project is subject to the terms of a license agreement to be concluded
+* with nymea GmbH in accordance with the terms of use of nymea GmbH, available
+* under https://nymea.io/license
+*
+* GNU Lesser General Public License Usage
+* Alternatively, this project may be redistributed and/or modified under the
+* terms of the GNU Lesser General Public License as published by the Free
+* Software Foundation; version 3. This project is distributed in the hope that
+* it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public License
+* along with this project. If not, see <https://www.gnu.org/licenses/>.
+*
+* For any further details and any questions please contact us under
+* contact@nymea.io or see our FAQ/Licensing Information on
+* https://nymea.io/license/faq
+*
+* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef DISCOVERY_H
+#define DISCOVERY_H
+
+#include <QObject>
+#include <QProcess>
+#include <QHostInfo>
+#include <QTimer>
+
+#include "host.h"
+
+class Discovery : public QObject
+{
+    Q_OBJECT
+public:
+    explicit Discovery(QObject *parent = nullptr);
+
+    void discoverHosts(int timeout);
+    void abort();
+
+    bool isRunning() const;
+
+
+signals:
+    void finished(QList<Host> hosts);
+
+private:
+    QStringList getDefaultTargets();
+
+    void finishDiscovery();
+
+private slots:
+    void discoveryFinished(int exitCode, QProcess::ExitStatus exitStatus);
+    void hostLookupDone(const QHostInfo &info);
+    void arpLookupDone(int exitCode, QProcess::ExitStatus exitStatus);
+    void onTimeout();
+
+private:
+    QList<QProcess*> m_discoveryProcesses;
+    QTimer m_timeoutTimer;
+
+    QHash<QProcess*, Host*> m_pendingArpLookups;
+    QHash<QString, Host*> m_pendingNameLookups;
+    QList<Host*> m_scanResults;
+
+};
+
+#endif // DISCOVERY_H
diff --git a/sma/host.cpp b/sma/host.cpp
new file mode 100644
index 00000000..2aec4ab6
--- /dev/null
+++ b/sma/host.cpp
@@ -0,0 +1,93 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+*
+* Copyright 2013 - 2020, nymea GmbH
+* Contact: contact@nymea.io
+*
+* This file is part of nymea.
+* This project including source code and documentation is protected by
+* copyright law, and remains the property of nymea GmbH. All rights, including
+* reproduction, publication, editing and translation, are reserved. The use of
+* this project is subject to the terms of a license agreement to be concluded
+* with nymea GmbH in accordance with the terms of use of nymea GmbH, available
+* under https://nymea.io/license
+*
+* GNU Lesser General Public License Usage
+* Alternatively, this project may be redistributed and/or modified under the
+* terms of the GNU Lesser General Public License as published by the Free
+* Software Foundation; version 3. This project is distributed in the hope that
+* it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public License
+* along with this project. If not, see <https://www.gnu.org/licenses/>.
+*
+* For any further details and any questions please contact us under
+* contact@nymea.io or see our FAQ/Licensing Information on
+* https://nymea.io/license/faq
+*
+* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#include "host.h"
+
+Host::Host()
+{
+    qRegisterMetaType<Host>();
+    qRegisterMetaType<QList<Host> >();
+}
+
+QString Host::macAddress() const
+{
+    return m_macAddress;
+}
+
+void Host::setMacAddress(const QString &macAddress)
+{
+    m_macAddress = macAddress;
+}
+
+QString Host::hostName() const
+{
+    return m_hostName;
+}
+
+void Host::setHostName(const QString &hostName)
+{
+    m_hostName = hostName;
+}
+
+QString Host::address() const
+{
+    return m_address;
+}
+
+void Host::setAddress(const QString &address)
+{
+    m_address = address;
+}
+
+void Host::seen()
+{
+    m_lastSeenTime = QDateTime::currentDateTime();
+}
+
+QDateTime Host::lastSeenTime() const
+{
+    return m_lastSeenTime;
+}
+
+bool Host::reachable() const
+{
+    return m_reachable;
+}
+
+void Host::setReachable(bool reachable)
+{
+    m_reachable = reachable;
+}
+
+QDebug operator<<(QDebug dbg, const Host &host)
+{
+    dbg.nospace() << "Host(" << host.macAddress() << "," << host.hostName() << ", " << host.address() << ", " << (host.reachable() ? "up" : "down") << ")";
+    return dbg.space();
+}
diff --git a/sma/host.h b/sma/host.h
new file mode 100644
index 00000000..84e48b0d
--- /dev/null
+++ b/sma/host.h
@@ -0,0 +1,69 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+*
+* Copyright 2013 - 2020, nymea GmbH
+* Contact: contact@nymea.io
+*
+* This file is part of nymea.
+* This project including source code and documentation is protected by
+* copyright law, and remains the property of nymea GmbH. All rights, including
+* reproduction, publication, editing and translation, are reserved. The use of
+* this project is subject to the terms of a license agreement to be concluded
+* with nymea GmbH in accordance with the terms of use of nymea GmbH, available
+* under https://nymea.io/license
+*
+* GNU Lesser General Public License Usage
+* Alternatively, this project may be redistributed and/or modified under the
+* terms of the GNU Lesser General Public License as published by the Free
+* Software Foundation; version 3. This project is distributed in the hope that
+* it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public License
+* along with this project. If not, see <https://www.gnu.org/licenses/>.
+*
+* For any further details and any questions please contact us under
+* contact@nymea.io or see our FAQ/Licensing Information on
+* https://nymea.io/license/faq
+*
+* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#ifndef HOST_H
+#define HOST_H
+
+#include <QString>
+#include <QDebug>
+#include <QDateTime>
+
+class Host
+{
+public:
+    Host();
+
+    QString macAddress() const;
+    void setMacAddress(const QString &macAddress);
+
+    QString hostName() const;
+    void setHostName(const QString &hostName);
+
+    QString address() const;
+    void setAddress(const QString &address);
+
+    void seen();
+    QDateTime lastSeenTime() const;
+
+    bool reachable() const;
+    void setReachable(bool reachable);
+
+private:
+    QString m_macAddress;
+    QString m_hostName;
+    QString m_address;
+    QDateTime m_lastSeenTime;
+    bool m_reachable;
+};
+Q_DECLARE_METATYPE(Host)
+
+QDebug operator<<(QDebug dbg, const Host &host);
+
+#endif // HOST_H
diff --git a/sma/integrationpluginsma.cpp b/sma/integrationpluginsma.cpp
index 64644a63..ac0e8ac8 100644
--- a/sma/integrationpluginsma.cpp
+++ b/sma/integrationpluginsma.cpp
@@ -40,6 +40,33 @@ void IntegrationPluginSma::discoverThings(ThingDiscoveryInfo *info)
 {
     if (info->thingClassId() == sunnyWebBoxThingClassId) {
 
+        Discovery *discovery = new Discovery(this);
+        discovery->discoverHosts(25);
+
+        // clean up discovery object when this discovery info is deleted
+        connect(info, &ThingDiscoveryInfo::destroyed, discovery, &Discovery::deleteLater);
+        connect(discovery, &Discovery::finished, info, [this, info](const QList<Host> &hosts) {
+            qCDebug(dcSma()) << "Discovery finished. Found" << hosts.count() << "devices";
+            foreach (const Host &host, hosts) {
+                if (host.hostName().contains("SMA Regelsysteme Gmbh")){
+                    ThingDescriptor descriptor(info->thingClassId(), host.hostName(), host.address() + " (" + host.macAddress() + ")");
+
+                    foreach (Thing *existingThing, myThings()) {
+                        if (existingThing->paramValue(sunnyWebBoxThingMacAddressParamTypeId).toString() == host.macAddress()) {
+                            descriptor.setThingId(existingThing->id());
+                            break;
+                        }
+                    }
+                    ParamList params;
+                    params << Param(sunnyWebBoxThingMacAddressParamTypeId, host.macAddress());
+                    params << Param(sunnyWebBoxThingHostParamTypeId, host.address());
+                    descriptor.setParams(params);
+
+                    info->addThingDescriptor(descriptor);
+                }
+            }
+            info->finish(Thing::ThingErrorNoError);
+        });
         info->finish(Thing::ThingErrorNoError);
     }
 }
diff --git a/sma/integrationpluginsma.h b/sma/integrationpluginsma.h
index e968dc17..76bc0324 100644
--- a/sma/integrationpluginsma.h
+++ b/sma/integrationpluginsma.h
@@ -35,6 +35,7 @@
 #include "plugintimer.h"
 #include "sunnywebbox.h"
 #include "sunnywebboxcommunication.h"
+#include "discovery.h"
 
 #include <QDebug>
 #include <QHostAddress>
diff --git a/sma/integrationpluginsma.json b/sma/integrationpluginsma.json
index c823b3f0..6b9a9920 100644
--- a/sma/integrationpluginsma.json
+++ b/sma/integrationpluginsma.json
@@ -24,11 +24,11 @@
                             "defaultValue": "192.168.0.168"
                         },
                         {
-                            "id": "a6df3d28-1b02-42dd-8301-81754c47e55f",
-                            "name": "id",
-                            "displayName": "Device ID",
+                            "id": "03f32361-4e13-4597-a346-af8d16a986b3",
+                            "name": "macAddress",
+                            "displayName": "hardware address",
                             "type": "QString",
-                            "defaultValue": "-",
+                            "inputType": "TextLine",
                             "readOnly": true
                         }
                     ],
diff --git a/sma/sma.pro b/sma/sma.pro
index 9f70bbdb..fcf5dcec 100644
--- a/sma/sma.pro
+++ b/sma/sma.pro
@@ -7,8 +7,12 @@ SOURCES += \
     integrationpluginsma.cpp \
     sunnywebbox.cpp \
     sunnywebboxcommunication.cpp \
+    host.cpp \
+    discovery.cpp
 
 HEADERS += \
     integrationpluginsma.h \
     sunnywebbox.h \
     sunnywebboxcommunication.h \
+    host.h \
+    discovery.h