MQTTSN_func.h

00001 int connack_rc = 0;
00002 int retryAttempt = 0;
00003 int connectTimeout = 1000;
00004 int rc = 0;
00005 
00006 enum connack_return_codes
00007 {
00008     MQTTSN_CONNECTION_ACCEPTED = 0,
00009     MQTTSN_REJECTED_CONGESTION = 1,
00010     MQTTSN_REJECTED_INVALID_TOPIC_ID = 2,
00011     MQTTSN_REJECTED_NOT_SUPPORTED= 3,
00012 };
00013 
00014 static volatile bool isMessageArrived = false;
00015 int arrivedcount = 0;
00016 
00017 int connect(MQTTSN::Client<MQTTSNUDP, Countdown> *client, MQTTSNUDP* ipstack)
00018 { 
00019     int rc;
00020     MQTTSNPacket_connectData data = MQTTSNPacket_connectData_initializer;       
00021     data.clientID.cstring = MQTT_CLIENT_ID;
00022     data.duration = 60;
00023     if ((rc = client->connect(data)) == 0) {
00024         printf ("--->MQTT-SN Connected\n\r");
00025     }
00026     else {
00027         printf("MQTT-SN connect returned %d\n", rc);        
00028     }
00029     if (rc >= 0)
00030         connack_rc = rc;
00031     return rc;
00032 }
00033 
00034 int getConnTimeout(int attemptNumber)
00035 {  // First 10 attempts try within 3 seconds, next 10 attempts retry after every 1 minute
00036    // after 20 attempts, retry every 10 minutes
00037     return (attemptNumber < 10) ? 3 : (attemptNumber < 20) ? 60 : 600;
00038 }
00039 
00040 void attemptConnect(MQTTSN::Client<MQTTSNUDP, Countdown> *client, MQTTSNUDP* ipstack)
00041 {          
00042     while (connect(client, ipstack) != MQTTSN_CONNECTION_ACCEPTED) 
00043     {    
00044         int timeout = getConnTimeout(++retryAttempt);
00045         printf("Retry attempt number %d waiting %d\n", retryAttempt, timeout);
00046         
00047         // if ipstack and client were on the heap we could deconstruct and goto a label where they are constructed
00048         //  or maybe just add the proper members to do this disconnect and call attemptConnect(...)        
00049         // this works - reset the system when the retry count gets to a threshold
00050         if (retryAttempt == 5)
00051             NVIC_SystemReset();
00052         else
00053             wait(timeout);
00054     }
00055 }
00056 
00057 void messageArrived(MQTTSN::MessageData& md)
00058 {
00059     MQTTSN::Message &message = md.message;
00060     printf("Message arrived: qos %d, retained %d, dup %d, packetid %d\n, Number: %d", message.qos, message.retained, message.dup, message.id, arrivedcount);
00061     memcpy(messageBuffer, (char*)message.payload, message.payloadlen);
00062     messageBuffer[message.payloadlen] = '\0';
00063     printf("Payload %.*s\n", message.payloadlen, (char*)message.payload);
00064     printf("Payload length %d\n",message.payloadlen);
00065     ++arrivedcount;
00066     process_msg();
00067     isMessageArrived = true;
00068 }
00069 
00070 int subscribe(MQTTSN::Client<MQTTSNUDP, Countdown> *client, MQTTSNUDP* ipstack, MQTTSN_topicid& topicid)
00071 {  
00072     //MQTTSN_topicid topicid;
00073     topicid.type = MQTTSN_TOPIC_TYPE_NORMAL;
00074     topicid.data.long_.name = MQTT_TOPIC;
00075     topicid.data.long_.len = strlen(MQTT_TOPIC);
00076     MQTTSN::QoS grantedQoS;
00077     return client->subscribe(topicid, MQTTSN::QOS1, grantedQoS, messageArrived);
00078 }
00079 
00080 int publish(MQTTSN::Client<MQTTSNUDP, Countdown> *client, MQTTSNUDP* ipstack, MQTTSN_topicid& topicid2)
00081 {
00082     int rc;
00083     if(PUB_REG == false)
00084     {
00085         if ((rc = subscribe(client, ipstack, topicid2)) != 0)
00086          printf("rc from MQTT subscribe is %d\n", rc);
00087     else{
00088          printf("Subscribed to Topic %s\n", MQTT_TOPIC);
00089          PUB_REG = true;
00090          }
00091     }
00092 
00093     MQTTSN::Message message;
00094     message.qos = MQTTSN::QOS1;
00095     message.retained = false;
00096     message.dup = false;
00097     message.payload = (void*)buf;
00098     message.payloadlen = strlen(buf)+1;
00099     return client->publish(topicid2, message);
00100 }