MQTT Client for mbed LPC1768 and Application Board over Ethernet; publish only.

Dependencies:   C12832 MMA7660 MQTT

Fork of HelloMQTT by MQTT

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.

Desktop MQTT-Clients

M3-Ethernet MQTT Client

M3-Ethernet ThingSpeak

C# Wpf Client

Weitere Kommunikationsmöglichkeiten

Revision:
5:4a257f6ac09a
Parent:
3:7a6a899de7cc
Child:
7:3de634f2d40c
--- a/main.cpp	Fri May 09 21:33:48 2014 +0000
+++ b/main.cpp	Fri May 09 23:06:43 2014 +0000
@@ -25,121 +25,45 @@
  */
 
 #include "mbed.h"
-#include "EthernetInterface.h"
+#include "EthernetInterfaceIPStack.h"
 
-#include "C12832_lcd.h"
-C12832_LCD lcd;
+#include "C12832.h"
+C12832 lcd(p5, p7, p6, p8, p11);
 
 #include "FP.cpp"
 #include "MQTTClient.h"
 
-
-
-class IPStack 
-{
-public:    
-    IPStack()
-    {
-        eth.init();                          // Use DHCP
-        eth.connect();
-        mysock.set_blocking(false, 1000);    // 1 second Timeout 
-    }
-    
-    int connect(char* hostname, int port)
-    {
-        return mysock.connect(hostname, port);
-    }
-
-    int read(char* buffer, int len, int timeout)
-    {
-        mysock.set_blocking(false, timeout);  
-        return mysock.receive(buffer, len);
-    }
-    
-    int write(char* buffer, int len, int timeout)
-    {
-        mysock.set_blocking(false, timeout);  
-        return mysock.send(buffer, len);
-    }
-    
-    int disconnect()
-    {
-        return mysock.close();
-    }
-    
-private:
-
-    EthernetInterface eth;
-    TCPSocketConnection mysock; 
-    
-};
-
-
-class Countdown
-{
-public:
-    Countdown()
-    {
-        t = Timer();   
-    }
-    
-    Countdown(int ms)
-    {
-        t = Timer();
-        countdown_ms(ms);   
-    }
-    
-    
-    bool expired()
-    {
-        return t.read_ms() >= interval_end_ms;
-    }
-    
-    void countdown_ms(int ms)  
-    {
-        t.stop();
-        interval_end_ms = ms;
-        t.reset();
-        t.start();
-    }
-    
-    void countdown(int seconds)
-    {
-        countdown_ms(seconds * 1000);
-    }
-    
-    int left_ms()
-    {
-        return interval_end_ms - t.read_ms();
-    }
-    
-private:
-    Timer t;
-    int interval_end_ms; 
-};
-
 int arrivedcount = 0;
 
 void messageArrived(MQTT::Message* message)
 {
-    lcd.printf("Message arrived: qos %d, retained %d, dup %d, packetid %d\n", message->qos, message->retained, message->dup, message->id);
-    lcd.printf("Payload %.*s\n", message->payloadlen, (char*)message->payload);
+    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.printf("Connecting to %s:%d\n", hostname, port);
+    
+    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("rc from TCP connect is %d\n", rc);
+    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("rc from MQTT connect is %d\n", rc);
+    lcd.printf("MQTT connect = %d\n", rc);
+    printf("rc from MQTT connect is %d\n", rc);
     
     return rc;
 }
@@ -152,6 +76,7 @@
     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);
     
@@ -161,8 +86,9 @@
     int rc = connect(&info);
     
     rc = client.subscribe(topic, MQTT::QOS1, messageArrived);   
-    if (rc != 0)
-        lcd.printf("rc from MQTT subscribe is %d\n", rc);
+    if (rc != 0) {
+        printf("rc from MQTT subscribe is %d\n", rc);
+    }
 
     MQTT::Message message;
 
@@ -195,16 +121,21 @@
         client.yield(100);
     
     rc = client.unsubscribe(topic);
-    if (rc != 0)
-        lcd.printf("rc from unsubscribe was %d\n", rc);
+    if (rc != 0) {
+        printf("rc from unsubscribe was %d\n", rc);
+    }
     
     rc = client.disconnect();
-    if (rc != 0)
-        lcd.printf("rc from disconnect was %d\n", rc);
+    if (rc != 0) {
+        printf("rc from disconnect was %d\n", rc);
+    }
     
     ipstack.disconnect();
     
-    lcd.printf("Finishing with %d messages received\n", arrivedcount);
+    lcd.cls();
+    lcd.locate(0,3);
+    lcd.printf("Finish: %d msgs\n", arrivedcount);
+    printf("Finishing with %d messages received\n", arrivedcount);
     
     return 0;
 }