asyncmqtt-sn's Introduction

Async MQTT-SN over UDP and XBee

Async MQTT-SN Gateway running on linux
Async MQTT-SN Client running on linux and Arduino Uno, Arduino Ethernet.
Design concept of Async client is defferent from Sync one. No more MQTT-SN Message classes.
Program size of Async client over UDP for Arduino is 21KB. over XBee is 16KB.
Gateway is changed to support Async PUBACK and SUBACK, DISCONNECT　responce.

For details, see Wiki

Supported functions

QoS Level 0, 1, 2
SEARCHGW, GWINFO
CONNECT, WILLTOPICREQ, WILLTOPIC, WILLMSGREQ, WILLMSG
PINGREQ, PINGRESP
CONNACK, REGISTER, REGACK, SUBACK, PUBACK, UNSUBACK
SUBSCRIBE, PUBLISH, UNSUBSCRIBE, DISCONNECT

Implemented control flows:
Application program executes PUBLISH() function,
Protocol flow as berrow is conducted automaticaly.

             Client              Gateway               Broker
  user coding   |                   |                    |      
                |                   |                    |    
   PUBLISH() -->| --- SERCHGW ----> |                    |  
                | <-- GWINFO  ----- |                    |  
                | --- CONNECT ----> |                    |  
                | <--WILLTOPICREQ-- |                    |  
                | --- WILLTOPIC --> |                    |  
                | <-- WILLMSGREQ -- |                    |  
                | --- WILLMSG ----> | ---- CONNECT ----> |(accepted)     
                | <-- CONNACK ----- | <--- CONNACK ----- |  
                | --- SUBSCRIBE --> | ---- SUBSCRIBE --> |     
 [set Callback] | <-- SUBACK ------ | <--- SUBACK ------ |   
                | --- REGISTER----> |                    |  
                | <-- REGACK  ----- |                    |  
                | --- PUBLISH ----> | ---- PUBLISH ----> |      
                | <-- PUBREC  ----- | <---- PUBREC ----- |    
                | --- PUBREL  ----> | ----- PUBREL ----> |    
                | <-- PUBCOMP ----- | <---- PUBCOMP----- |        
                |                   |                    |        
                //                  //                   //      
                | --- PINGREQ ----> | --- PINGREQ ---->  |         
                | <-- PINGRESP----- | <-- PINGRESP-----  |                    
                //                  //                   //    
                |                   |                    |    
                | <-- REGISTER ---- | <--- PUBLISH ----- |<-- PUBLISH  
                | --- REGACK  ----> |                    |  
[exec Callback] | <-- PUBLISH  ---- |                    |  
                | --- PUBACK   ---> | ---- PUBACK  ----> |--> PUBACK  
                |                   |                    |  
                //                  //                   //       
                |                   |                    |    
DISCONNECT() -->| ---DISCONNECT---> |                    |  
                | <--DISCONNECT---- |                    |