Sample MQTT program - simple send and receive (MQ Telemetry Transport) for GainSpan Wi-Fi module

Dependencies:   C12832 GSwifiInterface MQTT mbed-rtos mbed

Fork of HelloMQTT by MQTT

mbedのMQTTグループで保守されているMQTTライブラリを GainSpan Wi-Fi モジュールへ対応させたサンプルです。

MQTT (MQ Telemetry Transport) とは、IoTやM2M向け デバイス間通信のためのプロトコルです。

MQTTサーバーには http://iot.eclipse.org/ のサンドボックスを使います。 送信したメッセージをエコーバックしてくるだけの動作をします。


mbed Application Board を使う場合は次の行のコメントアウトを外すとLCDへ表示するようになる。

#define MBED_APPLICATION_BOARD

GainSpanモジュールの接続ピンについては次の行で指定する。

    gs = new GSwifiInterface(p9, p10, NC, NC, p30, NC, 9600); //tx, rx, cts, rts, reset, alarm, baud

Wi-Fiアクセスポイントは次の行で指定する。

#define SEC  GSwifi::SEC_WPA_PSK
#define SSID "SSID"
#define PASS "PASSPHRASE"

main.cpp

Committer:
sam_grove
Date:
2014-05-09
Revision:
5:4a257f6ac09a
Parent:
3:7a6a899de7cc
Child:
7:3de634f2d40c

File content as of revision 5:4a257f6ac09a:

/*******************************************************************************
 * 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
 *******************************************************************************/
 
 /**
  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.
 
 */

#include "mbed.h"
#include "EthernetInterfaceIPStack.h"

#include "C12832.h"
C12832 lcd(p5, p7, p6, p8, p11);

#include "FP.cpp"
#include "MQTTClient.h"

int arrivedcount = 0;

void messageArrived(MQTT::Message* message)
{
    lcd.cls();
    lcd.locate(0,3);
    printf("Message arrived: qos %d, retained %d, dup %d, packetid %d\n", message->qos, message->retained, message->dup, message->id);
    printf("Payload %.*s\n", message->payloadlen, (char*)message->payload);
    ++arrivedcount;
    lcd.puts((char*)message->payload);
}

int connect(MQTT::Client<IPStack, Countdown>::connectionLostInfo* info)
{
    char* hostname = "m2m.eclipse.org";
    int port = 1883;
    
    lcd.cls();
    lcd.locate(0,3);
    lcd.printf("%s:%d\n", hostname, port);
    printf("Connecting to %s:%d\n", hostname, port);
    int rc = info->network->connect(hostname, port);
    lcd.printf("TCP connect = %d\n", rc);
    printf("rc from TCP connect is %d\n", rc);
 
    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;       
    data.MQTTVersion = 3;
    data.clientID.cstring = "mbed-icraggs";
    rc = info->client->connect(&data);
    lcd.printf("MQTT connect = %d\n", rc);
    printf("rc from MQTT connect is %d\n", rc);
    
    return rc;
}


int main(int argc, char* argv[])
{   
    IPStack ipstack = IPStack();
    float version = 0.3;
    char* topic = "mbed-sample";
    
    lcd.printf("Version is %f\n", version);
    printf("Version is %f\n", version);
              
    MQTT::Client<IPStack, Countdown> client = MQTT::Client<IPStack, Countdown>(ipstack);
    
    client.setConnectionLostHandler(connect);

    MQTT::Client<IPStack, Countdown>::connectionLostInfo info = {&client, &ipstack};
    int rc = connect(&info);
    
    rc = client.subscribe(topic, MQTT::QOS1, messageArrived);   
    if (rc != 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 == 0)
        client.yield(100);
        
    // 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 == 1)
        client.yield(100);
        
    // 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 == 2)
        client.yield(100);
    
    rc = client.unsubscribe(topic);
    if (rc != 0) {
        printf("rc from unsubscribe was %d\n", rc);
    }
    
    rc = client.disconnect();
    if (rc != 0) {
        printf("rc from disconnect was %d\n", rc);
    }
    
    ipstack.disconnect();
    
    lcd.cls();
    lcd.locate(0,3);
    lcd.printf("Finish: %d msgs\n", arrivedcount);
    printf("Finishing with %d messages received\n", arrivedcount);
    
    return 0;
}