Add Adafruit_MQTT_Client class that implements MQTT code for generic Arduino client. Add ESP8266 example using new MQTT client class. Fix bugs with using library on ESP8266 (move CC3000 to header-only class).

Adafruit_MQTT_CC3000.h

@@ -1,6 +1,7 @@
 #ifndef _ADAFRUIT_MQTT_CC3000_H_
 #define _ADAFRUIT_MQTT_CC3000_H_
 
+#include <Adafruit_SleepyDog.h>
 #include <Adafruit_CC3000.h>
 #include "Adafruit_MQTT.h"
 
@@ -8,6 +9,10 @@
 #define MQTT_CC3000_INTERAVAILDELAY 10  
 
 
+// CC3000-specific version of the Adafruit_MQTT class.
+// Note that this is defined as a header-only class to prevent issues with using
+// the library on non-CC3000 platforms (since Arduino will include all .cpp files
+// in the compilation of the library).
 class Adafruit_MQTT_CC3000 : public Adafruit_MQTT {
  public:
   Adafruit_MQTT_CC3000(Adafruit_CC3000 *cc3k, const char *server, uint16_t port, 
@@ -16,11 +21,100 @@ class Adafruit_MQTT_CC3000 : public Adafruit_MQTT {
     cc3000(cc3k)
   {}
 
-  bool connectServer();
-  bool disconnect();
+  bool connectServer() {
+    uint32_t ip = 0;
+
+    Watchdog.reset();
+
+    // look up IP address
+    if (serverip == 0) {
+      // Try looking up the website's IP address using CC3K's built in getHostByName
+      strcpy_P((char *)buffer, servername);
+      Serial.print((char *)buffer); Serial.print(F(" -> "));
+      uint8_t dnsretries = 5;
+
+      Watchdog.reset();
+      while (ip == 0) {
+        if (! cc3000->getHostByName((char *)buffer, &ip)) {
+          Serial.println(F("Couldn't resolve!"));
+          dnsretries--;
+          Watchdog.reset();
+        }
+        //Serial.println("OK"); Serial.println(ip, HEX);
+        if (!dnsretries) return false;
+        delay(500);
+      }
+      
+      serverip = ip;
+      cc3000->printIPdotsRev(serverip);  
+      Serial.println();
+    }
+
+    Watchdog.reset();
+
+    // connect to server
+    DEBUG_PRINTLN(F("Connecting to TCP"));
+    mqttclient = cc3000->connectTCP(serverip, portnum);
+    
+    return mqttclient.connected();
+  }
+
+  bool disconnect() {
+    return (mqttclient.close() == 0); 
+  }
+
   uint16_t readPacket(uint8_t *buffer, uint8_t maxlen, int16_t timeout, 
-                      bool checkForValidPubPacket = false);
-  bool sendPacket(uint8_t *buffer, uint8_t len);
+                      bool checkForValidPubPacket = false) {
+    /* Read data until either the connection is closed, or the idle timeout is reached. */
+    uint16_t len = 0;
+    int16_t t = timeout;
+
+    while (mqttclient.connected() && (timeout >= 0)) {
+      //DEBUG_PRINT('.');
+      while (mqttclient.available()) {
+        //DEBUG_PRINT('!');
+        char c = mqttclient.read();
+        timeout = t;  // reset the timeout
+        buffer[len] = c;
+        //DEBUG_PRINTLN((uint8_t)c, HEX);
+        len++;
+        if (len == maxlen) {  // we read all we want, bail
+          DEBUG_PRINT(F("Read packet:\t"));
+          DEBUG_PRINTBUFFER(buffer, len);
+          return len;
+        }
+
+        // special case where we just one one publication packet at a time
+        if (checkForValidPubPacket) {
+          if ((buffer[0] == (MQTT_CTRL_PUBLISH << 4)) && (buffer[1] == len-2)) {
+            // oooh a valid publish packet!
+            DEBUG_PRINT(F("Read PUBLISH packet:\t"));
+            DEBUG_PRINTBUFFER(buffer, len);
+            return len;
+          }
+        }
+      }
+      Watchdog.reset();
+      timeout -= MQTT_CC3000_INTERAVAILDELAY;
+      delay(MQTT_CC3000_INTERAVAILDELAY);
+    }
+    return len;
+  }
+
+  bool sendPacket(uint8_t *buffer, uint8_t len) {
+    if (mqttclient.connected()) {
+      uint16_t ret = mqttclient.write(buffer, len);
+      DEBUG_PRINT(F("sendPacket returned: ")); DEBUG_PRINTLN(ret);
+      if (ret != len) {
+        DEBUG_PRINTLN("Failed to send complete packet.")
+        return false;
+      }
+    } else {
+      DEBUG_PRINTLN(F("Connection failed!"));
+      return false;
+    }
+    return true;
+  }
  
  private:
   uint32_t serverip;