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MQTT Client for mbed LPC1768 and Application Board over Ethernet; publish only.
Dependencies: C12832 MMA7660 MQTT
Fork of HelloMQTT by
Machine-to-Machine-Communication
Das Message Queue Telemetry Transport (MQTT) Protokoll ist ein effizientes Internet of Things (IoT) Protokoll mit wenig Protokolloverhead. Es wurde als lightweight publish/subscribe messaging transport entworfen. Es ist sinnvoll für Verbindungen mit Remote-Standorten, wo nur wenig Resourcen benötigt werden bzw. geringe Bandbreite zur Verfügung steht. Neben MQTT gibt es weitere IoT-Protokoll, wie HTTP, CoAP, XMPP, ... (Überischt über IoT Protokolle). Eine Beschreibung des MQTT ist z.B. hier zu finden.
MQTT implementiert das Publish/Subscribe-Pattern, daher wird ein Brocker für die Vermittlung der Nachrichten (topics) benötigt. Neben vielen quelloffenen Implementierungen (z. B. mosquitto) gibt es auch kommerzielle bzw. freie Server (Broker), die unterschiedliche Features bereit stellen (z. B. den in Deutschland entwickelten HiveMQ).
Für die Programmierung der Clients bzw. Ebedded Systems stehen ebenso sehr viele Libaries in verschiedenen Programmiersprachen zur Verfügung.
Weitere Kommunikationsmöglichkeiten
Diff: main.cpp
- Revision:
- 21:4b8d80bf664f
- Parent:
- 20:49c9daf2b0ff
--- a/main.cpp Tue Jan 10 18:10:17 2017 -0600 +++ b/main.cpp Thu May 04 10:07:14 2017 +0000 @@ -1,4 +1,5 @@ /******************************************************************************* + * Changed: PE, v0.71 works with Ethernet and random Client-ID * Copyright (c) 2014, 2015 IBM Corp. * * All rights reserved. This program and the accompanying materials @@ -15,18 +16,18 @@ * 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. +/** + 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 +// change this to 0 to output messages to serial instead of LCD +#define USE_LCD 0 #if USE_LCD #include "C12832.h" @@ -49,82 +50,91 @@ #include "MQTTmbed.h" #include "MQTTClient.h" -int arrivedcount = 0; +Serial pc(USBTX, USBRX); + +static const char alphanum[] = +"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; +int stringLength = sizeof(alphanum) - 1; +// use for random +#include "MMA7660.h" + +MMA7660 MMA(p28, p27); -void messageArrived(MQTT::MessageData& md) +char genRandom() { - MQTT::Message &message = md.message; - logMessage("Message arrived: qos %d, retained %d, dup %d, packetid %d\r\n", message.qos, message.retained, message.dup, message.id); - logMessage("Payload %.*s\r\n", message.payloadlen, (char*)message.payload); - ++arrivedcount; + if (MMA.testConnection()) + logMessage("get seed: Please shake the board for 1s \r\n"); + int x; + for (int i=0; i < 5; i++) { + x=(int) (MMA.z() * MMA.z() * MMA.z()*100)% 65; + //logMessage("seed: %d\r\n", x); + wait_ms(200); + } + srand (x); + return alphanum[rand() % stringLength]; } - int main(int argc, char* argv[]) { - float version = 0.6; - char* topic = "mbed-sample"; + float version = 0.71; + char* topic = "mbed/sample/Eth1"; - logMessage("HelloMQTT: version is %.2f\r\n", version); + logMessage("MQTT Publish PE: version is %.2f\r\n", version); + // connect to Ethernet-LAN with DHCP NetworkInterface* network = easy_connect(true); if (!network) { return -1; } - + + // connect to broker over Ethernet-LAN MQTTNetwork mqttNetwork(network); - MQTT::Client<MQTTNetwork, Countdown> client = MQTT::Client<MQTTNetwork, Countdown>(mqttNetwork); - const char* hostname = "m2m.eclipse.org"; + const char* hostname = "broker.hivemq.com"; // local RPi: 172.16.63.188; broker.hivemq.com: 35.157.21.220 int port = 1883; 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"; + + // generate a unique random Client-ID + char str[20] ="mbed-clientID-"; + srand(time(NULL)); + int i; + for(i = 14; i < 18; ++i) { + str[i] = genRandom(); + } + str[i] = 0; + data.clientID.cstring = str; + logMessage("ClientID: %s\r\n", data.clientID.cstring); + // only if authentication is used (not now): + // data.username.cstring = "testuser"; + // data.password.cstring = "testpassword"; if ((rc = client.connect(data)) != 0) logMessage("rc from MQTT connect is %d\r\n", rc); - if ((rc = client.subscribe(topic, MQTT::QOS2, messageArrived)) != 0) - logMessage("rc from MQTT subscribe is %d\r\n", rc); - MQTT::Message message; - // QoS 0 - char buf[100]; - sprintf(buf, "Hello World! QoS 0 message from app version %f\r\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) - client.yield(100); + // publish 5 messages + for(int t=0; t<5; t++) { + char buf[100]; + sprintf(buf, "28.4.2017/16:30/21"); // published message + message.qos = MQTT::QOS0; + message.retained = false; + message.dup = false; + message.payload = (void*)buf; + message.payloadlen = strlen(buf)+1; + rc = client.publish(topic, message); + wait(2); + } - // QoS 1 - sprintf(buf, "Hello World! QoS 1 message from app version %f\r\n", version); - message.qos = MQTT::QOS1; - message.payloadlen = strlen(buf)+1; - rc = client.publish(topic, message); - while (arrivedcount < 2) - client.yield(100); - - // QoS 2 - sprintf(buf, "Hello World! QoS 2 message from app version %f\r\n", version); - message.qos = MQTT::QOS2; - message.payloadlen = strlen(buf)+1; - rc = client.publish(topic, message); - while (arrivedcount < 3) - client.yield(100); - + // unsubscribe and disconnect from broker if ((rc = client.unsubscribe(topic)) != 0) logMessage("rc from unsubscribe was %d\r\n", rc); @@ -133,7 +143,7 @@ mqttNetwork.disconnect(); - logMessage("Version %.2f: finish %d msgs\r\n", version, arrivedcount); + logMessage("Version %.2f: finished\r\n", version); return 0; }