Sample MQTT program - simple send and receive

Dependencies:   C12832 MQTT

Fork of HelloMQTT by MQTT



File content as of revision 19:7f7aba7a4a8b:

 * Copyright (c) 2014, 2015 IBM Corp.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 * The Eclipse Public License is available at
 * and the Eclipse Distribution License is available at
 * Contributors:
 *    Ian Craggs - initial API and implementation and/or initial documentation
 *    Ian Craggs - make sure QoS2 processing works, and add device headers
  This is a sample program to illustrate the use of the MQTT Client library
  on the mbed platform.  The Client class requires two classes which mediate
  access to system interfaces for networking and timing.  As long as these two
  classes provide the required public programming interfaces, it does not matter
  what facilities they use underneath. In this program, they use the mbed
  system libraries.
 // change this to 0 to output messages to serial instead of LCD
#define USE_LCD 1

#include "C12832.h"

#if defined(TARGET_UBLOX_C027)
#warning "Compiling for mbed C027"
#include "C027.h"
#elif defined(TARGET_LPC1768)
#warning "Compiling for mbed LPC1768"
#include "LPC1768.h"
#elif defined(TARGET_K64F)
#warning "Compiling for mbed K64F"
#include "K64F.h"

#define printf lcd.cls();lcd.printf



#include "MQTTEthernet.h"
#include "MQTTClient.h"

int arrivedcount = 0;

void messageArrived(MQTT::MessageData& md)
    MQTT::Message &message = md.message;
    printf("Message arrived: qos %d, retained %d, dup %d, packetid %d\n", message.qos, message.retained, message.dup,;
    printf("Payload %.*s\n", message.payloadlen, (char*)message.payload);

int main(int argc, char* argv[])
    MQTTEthernet ipstack = MQTTEthernet();
    float version = 0.5;
    char* topic = "mbed-sample";
    printf("HelloMQTT: version is %f\n", version);
    MQTT::Client<MQTTEthernet, Countdown> client = MQTT::Client<MQTTEthernet, Countdown>(ipstack);
    char* hostname = "";
    int port = 1883;
    printf("Connecting to %s:%d\n", hostname, port);
    int rc = ipstack.connect(hostname, port);
    if (rc != 0)
        printf("rc from TCP connect is %d\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)
        printf("rc from MQTT connect is %d\n", rc);
    if ((rc = client.subscribe(topic, MQTT::QOS2, messageArrived)) != 0)
        printf("rc from MQTT subscribe is %d\n", rc);

    MQTT::Message message;

    // QoS 0
    char buf[100];
    sprintf(buf, "Hello World!  QoS 0 message from app version %f\n", version);
    message.qos = MQTT::QOS0;
    message.retained = false;
    message.dup = false;
    message.payload = (void*)buf;
    message.payloadlen = strlen(buf)+1;
    rc = client.publish(topic, message);
    while (arrivedcount < 1)
    // QoS 1
    sprintf(buf, "Hello World!  QoS 1 message from app version %f\n", version);
    message.qos = MQTT::QOS1;
    message.payloadlen = strlen(buf)+1;
    rc = client.publish(topic, message);
    while (arrivedcount < 2)
    // QoS 2
    sprintf(buf, "Hello World!  QoS 2 message from app version %f\n", version);
    message.qos = MQTT::QOS2;
    message.payloadlen = strlen(buf)+1;
    rc = client.publish(topic, message);
    while (arrivedcount < 3)
    if ((rc = client.unsubscribe(topic)) != 0)
        printf("rc from unsubscribe was %d\n", rc);
    if ((rc = client.disconnect()) != 0)
        printf("rc from disconnect was %d\n", rc);
    printf("Version %.2f: finish %d msgs\n", version, arrivedcount);
    return 0;