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1		-{{box cssClass="floatinginfobox" title="**Contents**"}}
2		-{{toc/}}
3		-{{/box}}
	1	+
4	4
5		-= Paragraph 1 =
	3	+= 1. What is MQTT API? =
6	6
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	5	+{{{MQTT is a publish/subscribe model that runs over TCP/IP sockets or WebSockets. MQTT over WebSockets can be secured with SSL.
8	8
9		-== Sub-paragraph ==
	7	+}}}
10	10
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12	12
13		-== Sub-paragraph ==
	10	+= 2. MQTT Features =
14	14
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	12	+The MQTT protocol runs on TCP / IP or other network protocols and provides an ordered, lossless, bidirectional connection. Features include:
16	16
17		-=== Sub-sub paragraph ===
	14	+* The publish / subscribe messaging pattern used, which provides one-to-many messaging for decoupling from the application.
	15	+* Message-masking mechanism for payload content.
	16	+* There are three Quality of Service (QoS) for transmitting messages:
	17	+* At most, messages of this level may be lost or duplicated, and message postings depend on the underlying TCP / IP network. That is: <= 1
	18	+* At one time, this level will ensure that the message arrives, but the message may be repeated. That is:> = 1
	19	+* Only once, make sure the message arrives only once. That is: = 1. In some demanding billing systems, you can use this level Data transfer and protocol exchange is minimized (protocol header only 2 bytes) to reduce network traffic
	20	+* Notification mechanism, notify the transmission of both sides when an exception occurs
18	18
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20	20
	23	+= 3. What does this example shows? How it works? =
21	21
22		-= Paragraph 2 =
	25	+The server we use here is ThingSpeak which has an intuitive chart to show the test result for our test.The ThingSpeak IoT service now supports MQTT subscriptions to receive instant updates when [[ThingSpeak>>url:https://thingspeak.com/]] channel gets updated. The method here is general and can be used with other IoT servers for MQTT connection as well.
23	23
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	27	+[[~[~[image:https://wiki.dragino.com/images/3/3d/MQTT_1.png~|~|height="68" width="260"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_1.png]]
25	25
26		-== Sub-paragraph ==
	29	+Message Queuing Telemetry Transport
27	27
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	31	+[[~[~[image:https://wiki.dragino.com/images/thumb/c/cb/YuanliMQTT.png/400px-YuanliMQTT.png~|~|height="139" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:YuanliMQTT.png]]
29	29
30		-== Sub-paragraph ==
	33	+working principle
31	31
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	35	+[[~[~[image:https://wiki.dragino.com/images/thumb/f/f9/MQTT_2.png/400px-MQTT_2.png~|~|height="160" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_2.png]]
	36	+
	37	+Schematic diagram: uplink.In this section, we will try to program LG01 to uplink data to ThingSpeak. The data flow in this example.We have already tried ① and ② in the above simple LoRa example. Now we will try the step ③ first, after it work as expect, we will integrate these three steps together for a complete uplink example.
	38	+
	39	+[[~[~[image:https://wiki.dragino.com/images/thumb/d/de/MQTT_3.png/400px-MQTT_3.png~|~|height="160" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_3.png]]
	40	+
	41	+Schematic diagram:downlink.In this section, we will try to program LG01 to fetch download data from ThingSpeak, then broadcast this data to local LoRa network. The end node will get this message and check if they need to do something. Similar with Uplink Example, we will first try to do it in PC, then do it in Linux side, and finally integrate it with LoRa.
	42	+
	43	+MQTT agreement to achieve the need: client and server There are three identities in the MQTT protocol: Publish, Broker (server), Subscribe. Among them, the publisher and the subscriber of the message are all clients, the broker is the server, and the publisher can be both the subscriber and the subscriber. MQTT transmission of information is divided into: Topic and payload in two parts Topic, can be understood as the type of message subscribers Subscribe, you will receive the theme of the message content (payload) The payload, which can be understood as the content of the message, refers to the specific content to be used by the subscribers.
	44	+
	45	+To use the server, we need to register an account on [[ThingSpeak>>url:https://thingspeak.com/]] . Then create a channel and type the channel info. As shown below, the Channel ID is the unique ID to store our data in [[ThingSpeak>>url:https://thingspeak.com/]] .
	46	+
	47	+
	48	+= 4. Preparation =
	49	+
	50	+== 4.1 Hardware ==
	51	+
	52	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/f/fb/2.png/300px-2.png~|~|height="283" width="300"~]~]>>url:https://wiki.dragino.com/index.php/File:2.png]](((
	53	+Listening on the LoRa wireless channel, while there is new LoRa packet arrives, parse it and send out to IoT Server.
	54	+)))
	55	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/4/4a/1.png/400px-1.png~|~|height="216" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:1.png]](((
	56	+The LoRa End node keeps getting temperature and humidity from the sensor and sends out via LoRa periodically.
	57	+)))
	58	+
	59	+
	60	+== 4.2 Software ==
	61	+
	62	+1. [[4.3.4 version>>url:http://www.dragino.com/downloads/index.php?dir=motherboards/ms14/Firmware/IoT/]]
	63	+1. [[MQTT_Client>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/IoTServer/ThingSpeak/MQTT_Client]]
	64	+1. [[MQTT_Simple_Server MQTT_Simeple_Server>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/LoRa/MQTT_Simple_Server]]
	65	+1. [[DHTlib>>url:https://github.com/goodcheney/Lora/blob/patch-1/Lora%20Shield/Examples/DHTlib.zip]]
	66	+
	67	+
	68	+
	69	+== 4.3 Server(For example) ==
	70	+
	71	+* [[ThingSpeak>>url:https://thingspeak.com/]]
	72	+
	73	+
	74	+== Configure IoT Server ==
	75	+
	76	+* Need this keys:
	77	+
	78	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/b/bc/Server1.png/400px-Server1.png~|~|height="185" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:Server1.png]](((
	79	+Channel ID,Write API Key
	80	+)))
	81	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/e/e2/Server2.png/400px-Server2.png~|~|height="128" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:Server2.png]](((
	82	+Account->My Profile,MQTT API Key
	83	+)))
	84	+1. (((
	85	+[[~[~[image:https://wiki.dragino.com/images/thumb/f/f3/IOT_Configure1.png/400px-IOT_Configure1.png~|~|alt="IOT Configure1.png" height="132" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:IOT_Configure1.png]]
	86	+)))
	87	+
	88	+
	89	+== Configure LG01 settings ==
	90	+
	91	+Tips:Please confirm that your LG01 version is 4.3.3.
	92	+
	93	+[[~[~[image:https://wiki.dragino.com/images/thumb/e/eb/LG01_Version.png/400px-LG01_Version.png~|~|height="219" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:LG01_Version.png]]
	94	+
	95	+Overview
	96	+
	97	+[[~[~[image:https://wiki.dragino.com/images/thumb/f/f6/MQTT_LG01_Configure_1.png/400px-MQTT_LG01_Configure_1.png~|~|height="281" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_LG01_Configure_1.png]]
	98	+
	99	+Senosor->IOT Server
	100	+
	101	+[[~[~[image:https://wiki.dragino.com/images/thumb/6/64/MQTT_LG01_Configure_2.png/400px-MQTT_LG01_Configure_2.png~|~|height="152" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_LG01_Configure_2.png]]
	102	+
	103	+MQTT->Configure MQTT Server
	104	+
	105	+[[~[~[image:https://wiki.dragino.com/images/thumb/6/6a/MQTT_LG01_Configure_3.png/400px-MQTT_LG01_Configure_3.png~|~|height="91" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_LG01_Configure_3.png]]
	106	+
	107	+MQTT->MQTT Channel
	108	+
	109	+[[~[~[image:https://wiki.dragino.com/images/thumb/3/36/MQTT_LG01_Configure_4.png/400px-MQTT_LG01_Configure_4.png~|~|height="257" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_LG01_Configure_4.png]]
	110	+
	111	+Sensor->LoRa/LoraWAN
	112	+
	113	+[[~[~[image:https://wiki.dragino.com/images/thumb/6/61/MQTT_LG01_Configure_5.png/400px-MQTT_LG01_Configure_5.png~|~|height="230" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_LG01_Configure_5.png]]
	114	+
	115	+Configure network access.Network->Internet Access
	116	+
	117	+
	118	+== Try MQTT API call with LG01 Linux command ==
	119	+
	120	+=== Input the command at the console ===
	121	+
	122	+1. [[~[~[image:https://wiki.dragino.com/images/8/84/3_1.png~|~|height="99" width="93"~]~]>>url:https://wiki.dragino.com/index.php/File:3_1.png]](((
	123	+Open this Application.
	124	+)))
	125	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/d/d7/3_2.png/400px-3_2.png~|~|height="230" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:3_2.png]](((
	126	+Input passward(dragino).After into the console.
	127	+)))
	128	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/5/5d/3_5.png/400px-3_5.png~|~|height="310" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:3_5.png]](((
	129	+First, we need to make sure the LG01 has internet access. We can log in the SSH and ping an Internet address and see if it get through. As below
	130	+)))
	131	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/6/63/3_3.png/400px-3_3.png~|~|height="213" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:3_3.png]](((
	132	+LG01 has built-in Linux tool mosquitto. It is a very powerful tool for http communication. We can use this tool to handle MQTT API call in LG01. Input this command and replace your keys.
	133	+)))
	134	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/3/35/3_4.png/500px-3_4.png~|~|height="180" width="500"~]~]>>url:https://wiki.dragino.com/index.php/File:3_4.png]](((
	135	+Go to Server check out result.We success to use LG01 to uplink data to ThingSpeak,the mosquitto_pub command is executed in the Linux side, finally, we will have to call mosquitto_pub command with sensor data variable in Arduino side. This is through the process class in Arduino and we will show it in the final sketch.
	136	+)))
	137	+
	138	+* This command:
	139	+
	140	+{{{mosquitto_pub -h mqtt.thingspeak.com -p 1883 -u dragino -P UZ4NGHKJMKS9WR5E -i dragino_Client -t channels/399171/publish/A4NNF6G8G63JOIUV -m "field1=23.5&field2=57.5&status=MQTTPUBLISH"
	141	+}}}
	142	+
	143	+* Need replace:
	144	+
	145	+{{{UZ4NGHKJMKS9WR5E //MQTT API
	146	+399171 //Channel ID
	147	+A4NNF6G8G63JOIUV //Write API Key
	148	+}}}
	149	+
	150	+
	151	+=== Input the command at the console(LG01 new version:4.3.4) ===
	152	+
	153	+1. [[~[~[image:https://wiki.dragino.com/images/8/84/3_1.png~|~|height="99" width="93"~]~]>>url:https://wiki.dragino.com/index.php/File:3_1.png]](((
	154	+Open this Application.
	155	+)))
	156	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/6/6e/MQTT_Command_2.png/400px-MQTT_Command_2.png~|~|height="76" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Command_2.png]](((
	157	+Check the settings.
	158	+)))
	159	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/8/8d/MQTT_Command_1.png/400px-MQTT_Command_1.png~|~|height="343" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Command_1.png]](((
	160	+input this command.
	161	+)))
	162	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/d/de/MQTT_Command_3.png/400px-MQTT_Command_3.png~|~|height="207" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Command_3.png]](((
	163	+Check the result.
	164	+)))
	165	+
	166	+== Updata data to Server(Through MQTT) ==
	167	+
	168	+* This version of Sketch implements these features:
	169	+
	170	+1. Read the LG01 configuration information from Linux.
	171	+1. Receive the LoRa node data and store the data in the /tmp/iot/channels
	172	+1. Send reply after then receive LoRa node data.
	173	+1. Sketch will write active content to /tmp/iot/status periodically (every 5 minutes).(Watchdog feature)
	174	+
	175	+
	176	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/8/82/MQTT_Sketch_2.png/400px-MQTT_Sketch_2.png~|~|height="233" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Sketch_2.png]](((
	177	+Open the sketch [[MQTT_Simple_Server>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/LoRa/MQTT_Simple_Server]].(Board:Dragino Yun + UNO or LG01/OLG01,Port:Network ports.)and upload.
	178	+)))
	179	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/7/73/MQTT_Sketch2.png/400px-MQTT_Sketch2.png~|~|height="540" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Sketch2.png]](((
	180	+Open Serial monitor.
	181	+)))
	182	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/9/98/MQTT_Sketch_1.png/400px-MQTT_Sketch_1.png~|~|height="261" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Sketch_1.png]](((
	183	+Open the Sketch [[MQTT_Client>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/IoTServer/ThingSpeak/MQTT_Client]]. (Board:Arduino/Genuino Uno.Port:Serial ports.)and upload.
	184	+)))
	185	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/3/3d/MQTT_Sketch3.png/400px-MQTT_Sketch3.png~|~|height="371" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Sketch3.png]](((
	186	+Open Serial monitor.
	187	+)))
	188	+1. Go to IoT Server to check the result.
	189	+1. (((
	190	+[[~[~[image:https://wiki.dragino.com/images/thumb/4/43/MQTT_result_1.png/400px-MQTT_result_1.png~|~|alt="MQTT result 1.png" height="181" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_result_1.png]]
	191	+)))
	192	+1. (((
	193	+[[~[~[image:https://wiki.dragino.com/images/thumb/7/70/MQTT_result_2.png/400px-MQTT_result_2.png~|~|alt="MQTT result 2.png" height="190" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_result_2.png]]
	194	+)))
	195	+
	196	+= FAQ =
	197	+
	198	+== Configure to support general mqtt server ==
	199	+
	200	+First, try to run **mosquitto_pub** in Linux console to send a data to MQTT server.
	201	+
	202	+For example: for ThingSpeak, a MQTT publish command is:
	203	+
	204	+{{{mosquitto_pub -h mqtt.thingspeak.com -p 1883 -u dragino -P QZXTAKE88V3S7O2J -i dragino_Client -t channels/200893/publish/B9Z0R25QNVEBKIFY -m "field1=34&field2=89&status=MQTTPUBLISH"
	205	+}}}
	206	+
	207	+What now we need to put in the LG01 is how to combine this command.
	208	+
	209	+1. LG01 web console -> Sensor -> MQTT
	210	+1. Choose general Server
	211	+1. [[~[~[image:https://wiki.dragino.com/images/thumb/e/ea/MQTT_Configure1.png/600px-MQTT_Configure1.png~|~|height="367" width="600"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Configure1.png]](((
	212	+Refer to your server to fill in.
	213	+)))
	214	+1. [[~[~[image:https://wiki.dragino.com/images/0/07/MQTT_Configure2.png~|~|height="93" width="538"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Configure2.png]](((
	215	+Ex:ThingSpeak Server
	216	+)))
	217	+
	218	+According to MQTT commands: mosquitto_pub, we need to put
	219	+
	220	+* server[-h] : mqtt.thingspeak.com
	221	+* port[-p] : 1883
	222	+* User Name[-u]: dragino
	223	+* Password[-P]:QZXTAKE88V3S7O2J
	224	+* Client ID[-i]: dragino_Client
	225	+* topic_format[-t]: channels/CHANNEL/publish/WRITE_API
	226	+* data_format[-m]: DATA&status=MQTTPUBLISH
	227	+
	228	+In the mqtt script, the upper **CHANNEL** will be replaced by the parameter (remote channel in IoT server). and the **WRITE_API** will be replaced by the settings in write api key. the **DATA** will be replaced by the value stored in the /var/iot/channels/LOCAL_CHANNEL file.
	229	+
	230	+MQTT script will keep checking the files in /var/iot/channels/ . If it find a match Local channel, then the MQTT script will send out the data of this local channel to a remote channel according to the setting above.
	231	+
	232	+User can also enable MQTT debug in the LG01 ~-~-> IoT Server settings and run logread in Linux console to see how the mqtt command is compose. below is an example:
	233	+
	234	+[[~[~[image:https://wiki.dragino.com/images/thumb/8/81/MQTT_Configure3.png/600px-MQTT_Configure3.png~|~|height="114" width="600"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Configure3.png]]
	235	+
	236	+MQTT Logread example
	237	+
	238	+
	239	+== What is Watchdog feature? ==
	240	+
	241	+LG01 for 4.3.3 version,we have added watchdog feature. In order to avoid the gateway running process will get stuck. So add writing action on every times.
	242	+
	243	+* [[~[~[image:https://wiki.dragino.com/images/thumb/f/f2/Wathcdog.png/400px-Wathcdog.png~|~|height="184" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:Wathcdog.png]](((
	244	+Enable Sensor->Micro-Controller settings
	245	+)))
	246	+* [[~[~[image:https://wiki.dragino.com/images/thumb/8/82/MQTT_Sketch_2.png/400px-MQTT_Sketch_2.png~|~|height="233" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:MQTT_Sketch_2.png]](((
	247	+Open the sketch [[MQTT_Simple_Server>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/LoRa/MQTT_Simple_Server]].(Board:Dragino Yun + UNO or LG01/OLG01,Port:Network ports.)and upload.
	248	+)))
	249	+* [[~[~[image:https://wiki.dragino.com/images/2/21/Loop.png~|~|height="181" width="388"~]~]>>url:https://wiki.dragino.com/index.php/File:Loop.png]](((
	250	+Each time the function loops, it uses the watchdog function once.
	251	+)))
	252	+* [[~[~[image:https://wiki.dragino.com/images/thumb/3/35/Dog.png/400px-Dog.png~|~|height="161" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:Dog.png]](((
	253	+Open SSH and check watchdog result.If the result change constantly,the feature enable successfully.
	254	+)))
	255	+* [[~[~[image:https://wiki.dragino.com/images/thumb/a/ac/Checkdog.png/400px-Checkdog.png~|~|height="222" width="400"~]~]>>url:https://wiki.dragino.com/index.php/File:Checkdog.png]](((
	256	+If the time doesnt's change,you can refer it to calculate for checking status.
	257	+)))
	258	+
	259	+== ==