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Wiki source code of Through MQTT to upload data

Version 44.2 by Xiaoling on 2022/05/31 14:32
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1 **Contents: **
2
3 {{toc/}}
4
5
6
7
8 = 1. What is MQTT API? =
9
10 {{{MQTT is a publish/subscribe model that runs over TCP/IP sockets or WebSockets. MQTT over WebSockets can be secured with SSL.}}}
11
12
13 = 2. MQTT Features =
14
15 The MQTT protocol runs on TCP / IP or other network protocols and provides an ordered, lossless, bidirectional connection. Features include:
16
17 * The publish / subscribe messaging pattern used, which provides one-to-many messaging for decoupling from the application.
18 * Message-masking mechanism for payload content.
19 * There are three Quality of Service (QoS) for transmitting messages:
20 * At most, messages of this level may be lost or duplicated, and message postings depend on the underlying TCP / IP network. That is: <= 1
21 * At one time, this level will ensure that the message arrives, but the message may be repeated. That is:> = 1
22 * 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
23 * Notification mechanism, notify the transmission of both sides when an exception occurs
24
25
26
27 = 3. What does this example shows? How it works? =
28
29 (((
30 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.
31 )))
32
33 [[image:image-20220531135402-1.png]]
34
35 Message Queuing Telemetry Transport
36
37
38 [[image:image-20220531135449-2.png]]
39
40 working principle
41
42
43 [[image:image-20220531135521-3.png]]
44
45 (((
46 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.
47 )))
48
49
50
51 [[image:image-20220531135607-4.png]]
52
53 (((
54 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.
55 )))
56
57 (((
58 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.
59 )))
60
61 (((
62 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/]] .
63 )))
64
65
66 = 4. Preparation =
67
68 == 4.1 Hardware ==
69
70 1. [[image:image-20220531135650-5.png]](((
71 Listening on the LoRa wireless channel, while there is new LoRa packet arrives, parse it and send out to IoT Server.
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73
74
75 )))
76 1. [[image:image-20220531135750-6.png]](((
77 The LoRa End node keeps getting temperature and humidity from the sensor and sends out via LoRa periodically.
78 )))
79
80 == 4.2 Software ==
81
82 1. [[4.3.4 version>>url:http://www.dragino.com/downloads/index.php?dir=motherboards/ms14/Firmware/IoT/]]
83 1. [[MQTT_Client>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/IoTServer/ThingSpeak/MQTT_Client]]
84 1. [[MQTT_Simple_Server MQTT_Simeple_Server>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/LoRa/MQTT_Simple_Server]]
85 1. [[DHTlib>>url:https://github.com/goodcheney/Lora/blob/patch-1/Lora%20Shield/Examples/DHTlib.zip]]
86
87 == 4.3 Server(For example) ==
88
89 * [[ThingSpeak>>url:https://thingspeak.com/]]
90
91 == 4.4 Configure IoT Server ==
92
93 * Need this keys:
94
95 1. [[image:image-20220531140054-8.png]](((
96 Channel ID,Write API Key
97
98
99
100 )))
101 1. [[image:image-20220531140326-13.png]](((
102 Account->My Profile,MQTT API Key
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106 )))
107 1. (((
108 [[image:image-20220531140304-12.png]]
109 )))
110
111 == 4.5 Configure LG01 settings ==
112
113 Tips:Please confirm that your LG01 version is 4.3.3.
114
115 [[image:image-20220531140248-11.png]]
116
117 **Overview**
118
119
120
121 [[image:image-20220531140425-14.png]]
122
123 **Senosor->IOT Server**
124
125
126 [[image:image-20220531140458-15.png]]
127
128 **MQTT->Configure MQTT Server**
129
130
131
132 [[image:image-20220531140538-16.png]]
133
134 **MQTT->MQTT Channel**
135
136
137
138 [[image:image-20220531140611-17.png]]
139
140 **Sensor->LoRa/LoraWAN**
141
142
143
144 [[image:image-20220531140651-18.png]]
145
146 Configure network access.**Network->Internet Access**
147
148
149 == 4.6 Try MQTT API call with LG01 Linux command ==
150
151 === 4.6.1 Input the command at the console ===
152
153 1. [[image:image-20220531140811-19.png]](((
154 Open this Application.
155
156
157 )))
158 1. [[image:image-20220531140842-20.png]](((
159 Input passward(dragino).After into the console.
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161
162 )))
163 1. [[image:image-20220531140915-21.png]](((
164 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
165
166
167 )))
168 1. [[image:image-20220531140955-22.png]](((
169 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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171
172
173 )))
174 1. [[image:image-20220531141026-23.png]](((
175 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.
176 )))
177
178 * This command:
179
180 (% class="box infomessage" %)
181 (((
182 **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"**
183 )))
184
185 * Need replace:
186
187 (% class="box infomessage" %)
188 (((
189 **UZ4NGHKJMKS9WR5E  ~/~/MQTT API
190 399171            ~/~/Channel ID
191 A4NNF6G8G63JOIUV  ~/~/Write API Key**
192 )))
193
194
195 === 4.6.2 Input the command at the console(LG01 new version:4.3.4) ===
196
197 1. [[image:image-20220531141150-24.png]](((
198 Open this Application.
199
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201
202 )))
203 1. (((
204 [[image:image-20220531141400-27.png]]
205
206 Check the settings.
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210 )))
211 1. (((
212 [[image:image-20220531141601-30.png]]
213
214 input this command.
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218 )))
219 1. [[image:image-20220531141515-29.png]](((
220 Check the result.
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223
224 )))
225
226 == 4.7 Updata data to Server(Through MQTT) ==
227
228 * This version of Sketch implements these features:
229
230 1. Read the LG01 configuration information from Linux.
231 1. Receive the LoRa node data and store the data in the /tmp/iot/channels
232 1. Send reply after then receive LoRa node data.
233 1. Sketch will write active content to /tmp/iot/status periodically (every 5 minutes).(Watchdog feature)
234
235 1. [[image:image-20220531141656-31.png]](((
236 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.
237
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239
240 )))
241 1. [[image:image-20220531141800-32.png]](((
242 Open Serial monitor.
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245
246 )))
247 1. [[image:image-20220531141842-33.png]](((
248 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.
249
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251
252 )))
253 1. [[image:image-20220531141927-34.png]](((
254 Open Serial monitor.
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256
257
258 )))
259 1. Go to IoT Server to check the result.
260 1. (((
261 [[image:image-20220531142023-35.png]]
262
263
264
265 )))
266 1. (((
267 [[image:image-20220531142155-36.png]]
268
269
270
271 )))
272
273 = 5. FAQ =
274
275 == 5.1 Configure to support general mqtt server ==
276
277 First, try to run **mosquitto_pub** in Linux console to send a data to MQTT server.
278
279 For example: for ThingSpeak, a MQTT publish command is:
280
281 (% class="box infomessage" %)
282 (((
283 **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"**
284 )))
285
286 What now we need to put in the LG01 is how to combine this command.
287
288 1. LG01 web console -> Sensor -> MQTT
289 1. Choose general Server
290 1. [[image:image-20220531142342-37.png]](((
291 Refer to your server to fill in.
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295 )))
296 1. [[image:image-20220531142447-38.png]](((
297 Ex:ThingSpeak Server
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299
300 )))
301
302 According to MQTT commands: mosquitto_pub, we need to put
303
304 * server[-h] : mqtt.thingspeak.com
305 * port[-p] : 1883
306 * User Name[-u]: dragino
307 * Password[-P]:QZXTAKE88V3S7O2J
308 * Client ID[-i]: dragino_Client
309 * topic_format[-t]: channels/CHANNEL/publish/WRITE_API
310 * data_format[-m]: DATA&status=MQTTPUBLISH
311
312 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.
313
314 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.
315
316 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:
317
318 [[image:image-20220531142525-39.png]]
319
320 MQTT Logread example
321
322
323 == 5.2 What is Watchdog feature? ==
324
325 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.
326
327 * [[image:image-20220531142558-40.png]](((
328 Enable Sensor->Micro-Controller settings
329
330
331
332 )))
333 * [[image:image-20220531142629-41.png]](((
334 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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336
337
338 )))
339 * [[image:image-20220531142659-42.png]](((
340 Each time the function loops, it uses the watchdog function once.
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343
344 )))
345 * [[image:image-20220531142720-43.png]](((
346 Open SSH and check watchdog result.If the result change constantly,the feature enable successfully.
347
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350 )))
351 * [[image:image-20220531142748-44.png]](((
352 If the time doesnt's change,you can refer it to calculate for checking status.
353 )))
354
355 (% class="wikigeneratedid" id="H" %)
356