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.

Revision:
2:638c854c0695
Parent:
1:a1d5c7a6acbc
Child:
3:7a6a899de7cc
--- a/main.cpp	Wed Feb 05 10:50:15 2014 +0000
+++ b/main.cpp	Wed Apr 30 13:16:09 2014 +0000
@@ -13,77 +13,198 @@
  * 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 "EthernetInterface.h"
+
 #include "C12832_lcd.h"
-
-#include "MQTTPacket.h"
-
-DigitalOut myled(LED2);
 C12832_LCD lcd;
 
-int publish()
+#include "FP.cpp"
+#include "MQTTClient.h"
+
+
+
+class IPStack 
 {
-    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
-    int rc = 0;
-    char buf[200];
-    int buflen = sizeof(buf);
+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; 
-    MQTTString topicString = MQTTString_initializer;
-    char* payload = "I'm alive!";
-    int payloadlen = strlen(payload);
-    int len = 0;
+    
+};
+
+
+class Countdown
+{
+public:
+    Countdown()
+    {
+        t = Timer();   
+    }
+    
+    Countdown(int ms)
+    {
+        t = Timer();
+        countdown_ms(ms);   
+    }
+    
     
-    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);
+    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; 
+};
 
-    topicString.cstring = "mbed NXP LPC1768";
-    len += MQTTSerialize_publish(buf + len, buflen - len, 0, 0, 0, 0, topicString, payload, payloadlen);
+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);
+    ++arrivedcount;
+}
 
-    len += MQTTSerialize_disconnect(buf + len, buflen - len);
+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);
+    int rc = info->network->connect(hostname, port);
+    lcd.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);
+    
+    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);
+              
+    MQTT::Client<IPStack, Countdown>client = MQTT::Client<IPStack, Countdown>(&ipstack);
 
-    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);
+    MQTT::Client<IPStack, Countdown>::connectionLostInfo info = {&client, &ipstack};
+    int rc = connect(&info);
+    
+    client.setConnectionLostHandler(connect);
+    
+    rc = client.subscribe(topic, MQTT::QOS1, messageArrived);   
+    if (rc != 0)
+        lcd.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)
+        lcd.printf("rc from unsubscribe was %d\n", rc);
+    
+    rc = client.disconnect();
+    if (rc != 0)
+        lcd.printf("rc from disconnect was %d\n", rc);
+    
+    ipstack.disconnect();
+    
+    lcd.printf("Finishing with %d messages received\n", arrivedcount);
+    
     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();
-}