File content as of revision 20:88b9edbdf125:

/** MQTT Publish von Sensordaten */
#include "mbed.h"
#include "easy-connect.h"
#include "MQTTNetwork.h"
#include "MQTTmbed.h"
#include "MQTTClient.h"

#define logMessage printf

// Topic's
char* topicLight = "mbed/k64f/iotkit/light";
char* topicPoti = "mbed/k64f/iotkit/poti";
// MQTT Brocker
char* hostname = "192.168.178.43";
int port = 31883;
// MQTT Message
MQTT::Message message;
// I/O Buffer
char buf[100];
// UI
DigitalOut led1( D10 );
// Poti
AnalogIn   poti( A0 );
// Lichtsensor
AnalogIn   light( A1 );

/** Hilfsfunktion zum Publizieren auf MQTT Broker */
void publish( MQTTNetwork &mqttNetwork, MQTT::Client<MQTTNetwork, Countdown> &client )
{
    logMessage("Connecting to %s:%d\r\n", hostname, port);
    int rc = mqttNetwork.connect(hostname, port);
    if (rc != 0)
        logMessage("rc from TCP connect is %d\r\n", rc);

    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    data.MQTTVersion = 3;
    data.clientID.cstring = "mbed-sample";
    data.username.cstring = "testuser";
    data.password.cstring = "testpassword";
    if ((rc = client.connect(data)) != 0)
        logMessage("rc from MQTT connect is %d\r\n", rc);

    MQTT::Message message;    
    
    // Message als JSON aufbereiten und senden
    /*sprintf( buf, "%f", light.read() );
    printf( "Publish: %s\n", buf );
    message.qos = MQTT::QOS0;
    message.retained = false;
    message.dup = false;
    message.payload = (void*) buf;
    message.payloadlen = strlen(buf)+1;
    client.publish( topicLight, message);*/
    
    // Message als JSON aufbereiten und senden
    sprintf( buf, "%f", poti.read() );
    printf( "Publish: %s\n", buf );
    message.qos = MQTT::QOS0;
    message.retained = false;
    message.dup = false;
    message.payload = (void*) buf;
    message.payloadlen = strlen(buf)+1;
    client.publish( topicPoti, message);    
    
    // Verbindung beenden, ansonsten ist nach 4x Schluss
    if ((rc = client.disconnect()) != 0)
        logMessage("rc from disconnect was %d\r\n", rc);

    mqttNetwork.disconnect();
}

/** Hauptprogramm */
int main()
{
    logMessage("MQTTPublish\n");

    NetworkInterface* network = easy_connect(true);
    if (!network) 
        return -1;

    // TCP/IP und MQTT initialisieren (muss in main erfolgen)
    MQTTNetwork mqttNetwork(network);
    MQTT::Client<MQTTNetwork, Countdown> client(mqttNetwork);

    while   ( 1 ) 
    {
        led1 = 1;
        publish( mqttNetwork, client );
        led1 = 0;
        wait    ( 5.0 );
    }
}