Wiki source code of Through MQTT to upload data

Version 42.2 by Xiaoling on 2022/05/31 14:27

version	line-number	content
1.4	1	{{toc/}}
1.1	2
1.4	3
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1.2	6	= 1. What is MQTT API? =
1.1	7
1.5	8	{{{MQTT is a publish/subscribe model that runs over TCP/IP sockets or WebSockets. MQTT over WebSockets can be secured with SSL.}}}
1.1	9
	10
1.2	11	= 2. MQTT Features =
1.1	12
1.2	13	The MQTT protocol runs on TCP / IP or other network protocols and provides an ordered, lossless, bidirectional connection. Features include:
1.1	14
1.2	15	* The publish / subscribe messaging pattern used, which provides one-to-many messaging for decoupling from the application.
	16	* Message-masking mechanism for payload content.
	17	* There are three Quality of Service (QoS) for transmitting messages:
	18	* At most, messages of this level may be lost or duplicated, and message postings depend on the underlying TCP / IP network. That is: <= 1
	19	* At one time, this level will ensure that the message arrives, but the message may be repeated. That is:> = 1
	20	* 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
	21	* Notification mechanism, notify the transmission of both sides when an exception occurs
1.1	22
	23
1.2	24	= 3. What does this example shows? How it works? =
1.1	25
1.2	26	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.
1.1	27
3.2	28	[[image:image-20220531135402-1.png]]
1.1	29
1.2	30	Message Queuing Telemetry Transport
1.1	31
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3.2	33	[[image:image-20220531135449-2.png]]
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1.2	35	working principle
1.1	36
3.2	37
4.2	38	[[image:image-20220531135521-3.png]]
1.2	39
	40	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.
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4.2	42
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5.2	44	[[image:image-20220531135607-4.png]]
1.2	45
	46	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.
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	48	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.
	49
	50	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/]] .
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	52
	53	= 4. Preparation =
	54
	55	== 4.1 Hardware ==
	56
6.2	57	1. [[image:image-20220531135650-5.png]](((
1.2	58	Listening on the LoRa wireless channel, while there is new LoRa packet arrives, parse it and send out to IoT Server.
6.2	59
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1.2	62	)))
7.2	63	1. [[image:image-20220531135750-6.png]](((
1.2	64	The LoRa End node keeps getting temperature and humidity from the sensor and sends out via LoRa periodically.
	65	)))
	66
	67
	68	== 4.2 Software ==
	69
	70	1. [[4.3.4 version>>url:http://www.dragino.com/downloads/index.php?dir=motherboards/ms14/Firmware/IoT/]]
	71	1. [[MQTT_Client>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/IoTServer/ThingSpeak/MQTT_Client]]
	72	1. [[MQTT_Simple_Server MQTT_Simeple_Server>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/LoRa/MQTT_Simple_Server]]
	73	1. [[DHTlib>>url:https://github.com/goodcheney/Lora/blob/patch-1/Lora%20Shield/Examples/DHTlib.zip]]
	74
	75
	76	== 4.3 Server(For example) ==
	77
	78	* [[ThingSpeak>>url:https://thingspeak.com/]]
	79
	80
1.3	81	== 4.4 Configure IoT Server ==
1.2	82
	83	* Need this keys:
	84
9.2	85	1. [[image:image-20220531140054-8.png]](((
1.2	86	Channel ID,Write API Key
8.3	87
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1.2	90	)))
14.2	91	1. [[image:image-20220531140326-13.png]](((
1.2	92	Account->My Profile,MQTT API Key
10.2	93
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1.2	96	)))
	97	1. (((
14.2	98	[[image:image-20220531140304-12.png]]
1.2	99	)))
	100
	101
1.3	102	== 4.5 Configure LG01 settings ==
1.2	103
	104	Tips:Please confirm that your LG01 version is 4.3.3.
	105
14.2	106	[[image:image-20220531140248-11.png]]
1.2	107
19.3	108	Overview
1.2	109
14.3	110
	111
15.2	112	[[image:image-20220531140425-14.png]]
1.2	113
19.3	114	Senosor->IOT Server
1.2	115
15.2	116
16.2	117	[[image:image-20220531140458-15.png]]
1.2	118
19.3	119	MQTT->Configure MQTT Server
1.2	120
16.2	121
	122
17.2	123	[[image:image-20220531140538-16.png]]
1.2	124
19.3	125	MQTT->MQTT Channel
1.2	126
17.2	127
	128
18.2	129	[[image:image-20220531140611-17.png]]
1.2	130
19.3	131	Sensor->LoRa/LoraWAN
1.2	132
18.2	133
	134
19.2	135	[[image:image-20220531140651-18.png]]
1.2	136
19.3	137	Configure network access.Network->Internet Access
1.2	138
	139
1.3	140	== 4.6 Try MQTT API call with LG01 Linux command ==
1.2	141
1.3	142	=== 4.6.1 Input the command at the console ===
1.2	143
21.2	144	1. [[image:image-20220531140811-19.png]](((
1.2	145	Open this Application.
21.2	146
	147
1.2	148	)))
21.2	149	1. [[image:image-20220531140842-20.png]](((
1.2	150	Input passward(dragino).After into the console.
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1.2	153	)))
22.2	154	1. [[image:image-20220531140915-21.png]](((
1.2	155	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
22.3	156
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1.2	158	)))
23.2	159	1. [[image:image-20220531140955-22.png]](((
1.2	160	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.
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1.2	164	)))
24.2	165	1. [[image:image-20220531141026-23.png]](((
1.2	166	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.
	167	)))
	168
	169	* This command:
	170
24.3	171	(% class="box infomessage" %)
	172	(((
	173	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"
	174	)))
1.2	175
	176	* Need replace:
	177
24.3	178	(% class="box infomessage" %)
	179	(((
	180	**UZ4NGHKJMKS9WR5E ~/~/MQTT API
	181	399171 ~/~/Channel ID
	182	A4NNF6G8G63JOIUV ~/~/Write API Key**
	183	)))
1.2	184
	185
1.3	186	=== 4.6.2 Input the command at the console(LG01 new version:4.3.4) ===
1.2	187
25.2	188	1. [[image:image-20220531141150-24.png]](((
1.2	189	Open this Application.
25.2	190
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1.2	193	)))
27.2	194	1. (((
	195	[[image:image-20220531141400-27.png]]
	196
1.2	197	Check the settings.
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1.2	201	)))
28.2	202	1. (((
29.2	203	[[image:image-20220531141601-30.png]]
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1.2	205	input this command.
27.2	206
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1.2	209	)))
28.2	210	1. [[image:image-20220531141515-29.png]](((
1.2	211	Check the result.
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1.2	215	)))
	216
1.3	217	== 4.7 Updata data to Server(Through MQTT) ==
1.2	218
	219	* This version of Sketch implements these features:
	220
	221	1. Read the LG01 configuration information from Linux.
	222	1. Receive the LoRa node data and store the data in the /tmp/iot/channels
	223	1. Send reply after then receive LoRa node data.
	224	1. Sketch will write active content to /tmp/iot/status periodically (every 5 minutes).(Watchdog feature)
	225
	226
30.2	227	1. [[image:image-20220531141656-31.png]](((
1.2	228	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.
30.2	229
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1.2	232	)))
31.2	233	1. [[image:image-20220531141800-32.png]](((
1.2	234	Open Serial monitor.
31.2	235
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1.2	238	)))
32.2	239	1. [[image:image-20220531141842-33.png]](((
1.2	240	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.
32.2	241
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1.2	244	)))
33.2	245	1. [[image:image-20220531141927-34.png]](((
1.2	246	Open Serial monitor.
33.2	247
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1.2	250	)))
	251	1. Go to IoT Server to check the result.
	252	1. (((
34.2	253	[[image:image-20220531142023-35.png]]
	254
35.2	255
34.2	256
1.2	257	)))
	258	1. (((
35.2	259	[[image:image-20220531142155-36.png]]
35.3	260
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	262
1.2	263	)))
	264
1.3	265	= 5. FAQ =
1.2	266
1.3	267	== 5.1 Configure to support general mqtt server ==
1.2	268
	269	First, try to run mosquitto_pub in Linux console to send a data to MQTT server.
	270
	271	For example: for ThingSpeak, a MQTT publish command is:
	272
36.2	273	(% class="box infomessage" %)
	274	(((
	275	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"
	276	)))
1.2	277
	278	What now we need to put in the LG01 is how to combine this command.
	279
	280	1. LG01 web console -> Sensor -> MQTT
	281	1. Choose general Server
36.2	282	1. [[image:image-20220531142342-37.png]](((
1.2	283	Refer to your server to fill in.
36.2	284
	285
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1.2	287	)))
37.2	288	1. [[image:image-20220531142447-38.png]](((
1.2	289	Ex:ThingSpeak Server
37.2	290
	291
1.2	292	)))
	293
	294	According to MQTT commands: mosquitto_pub, we need to put
	295
	296	* server[-h] : mqtt.thingspeak.com
	297	* port[-p] : 1883
	298	* User Name[-u]: dragino
	299	* Password[-P]:QZXTAKE88V3S7O2J
	300	* Client ID[-i]: dragino_Client
	301	* topic_format[-t]: channels/CHANNEL/publish/WRITE_API
	302	* data_format[-m]: DATA&status=MQTTPUBLISH
	303
	304	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.
	305
	306	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.
	307
	308	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:
	309
38.2	310	[[image:image-20220531142525-39.png]]
1.2	311
	312	MQTT Logread example
	313
	314
1.3	315	== 5.2 What is Watchdog feature? ==
1.2	316
	317	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.
	318
39.2	319	* [[image:image-20220531142558-40.png]](((
1.2	320	Enable Sensor->Micro-Controller settings
39.3	321
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1.2	324	)))
40.2	325	* [[image:image-20220531142629-41.png]](((
1.2	326	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.
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1.2	330	)))
41.2	331	* [[image:image-20220531142659-42.png]](((
1.2	332	Each time the function loops, it uses the watchdog function once.
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1.2	336	)))
42.2	337	* [[image:image-20220531142720-43.png]](((
1.2	338	Open SSH and check watchdog result.If the result change constantly,the feature enable successfully.
42.2	339
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1.2	342	)))
	343	* [[~[~[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]](((
	344	If the time doesnt's change,you can refer it to calculate for checking status.
	345	)))
	346
	347	== ==

Wiki source code of Through MQTT to upload data

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