Example MQTT implemented on the ESP8266

Dependencies:   ESP8266Interface MQTT mbed-rtos mbed

Fork of HelloMQTT by MQTT

This is an example of how to run MQTT using the esp8266 as the network connection. This program will default to trying to talk to a public MQTT server (test.mosquitto.org). The example will subscribe to a topic and then publish to that topic. In this way it will effectively echo back to itself. You can alternatively use a private mqtt broker,[[TODO: |instructions here]]

Please note that the ESP8266 interface cannot translate hostnames to IP Addresses, it can only accept raw IP Addresses as input.

main.cpp

Committer:
icraggs
Date:
2014-02-05
Revision:
1:a1d5c7a6acbc
Parent:
0:0cae29831d01
Child:
2:638c854c0695

File content as of revision 1:a1d5c7a6acbc:

/*******************************************************************************
 * Copyright (c) 2014 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
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Ian Craggs - initial API and implementation and/or initial documentation
 *******************************************************************************/

#include "mbed.h"
#include "EthernetInterface.h"
#include "C12832_lcd.h"

#include "MQTTPacket.h"

DigitalOut myled(LED2);
C12832_LCD lcd;

int publish()
{
    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    int rc = 0;
    char buf[200];
    int buflen = sizeof(buf);
    TCPSocketConnection mysock; 
    MQTTString topicString = MQTTString_initializer;
    char* payload = "I'm alive!";
    int payloadlen = strlen(payload);
    int len = 0;
    
    mysock.connect("m2m.eclipse.org", 1883);
          
    data.clientID.cstring = "mbed test client - Ian Craggs";
    data.keepAliveInterval = 20;
    data.cleansession = 1;
    data.MQTTVersion = 3;

    len = MQTTSerialize_connect(buf, buflen, &data);

    topicString.cstring = "mbed NXP LPC1768";
    len += MQTTSerialize_publish(buf + len, buflen - len, 0, 0, 0, 0, topicString, payload, payloadlen);

    len += MQTTSerialize_disconnect(buf + len, buflen - len);

    rc = 0;
    while (rc < len)
    {
        int rc1 = mysock.send(buf, len);
        if (rc1 == -1)
        {
            lcd.printf("Send failed\n");
            break;
        }
        else
            rc += rc1;
    }
    if (rc == len)
        lcd.printf("Send succeeded\n");
    wait(0.2);

    return 0;
}

int main()
{
    EthernetInterface eth;
    eth.init(); //Use DHCP
    eth.connect();
    lcd.printf("IP Address is %s\n", eth.getIPAddress());
    
    while(1) 
    {
        myled = 1;
        publish();
        wait(0.2);
        myled = 0;
        publish();
        wait(0.2);
    }
    
    eth.disconnect();
}