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Wiki source code of Through MQTT to upload data

Version 44.5 by Xiaoling on 2022/05/31 14:33
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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
67 = 4. Preparation =
68
69 == 4.1 Hardware ==
70
71 1. [[image:image-20220531135650-5.png]](((
72 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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74
75
76 )))
77 1. [[image:image-20220531135750-6.png]](((
78 The LoRa End node keeps getting temperature and humidity from the sensor and sends out via LoRa periodically.
79 )))
80
81 == 4.2 Software ==
82
83 1. [[4.3.4 version>>url:http://www.dragino.com/downloads/index.php?dir=motherboards/ms14/Firmware/IoT/]]
84 1. [[MQTT_Client>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/IoTServer/ThingSpeak/MQTT_Client]]
85 1. [[MQTT_Simple_Server MQTT_Simeple_Server>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/LoRa/MQTT_Simple_Server]]
86 1. [[DHTlib>>url:https://github.com/goodcheney/Lora/blob/patch-1/Lora%20Shield/Examples/DHTlib.zip]]
87
88
89
90 == 4.3 Server(For example) ==
91
92 * [[ThingSpeak>>url:https://thingspeak.com/]]
93
94
95
96 == 4.4 Configure IoT Server ==
97
98 * Need this keys:
99
100 1. [[image:image-20220531140054-8.png]](((
101 Channel ID,Write API Key
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103
104
105 )))
106 1. [[image:image-20220531140326-13.png]](((
107 Account->My Profile,MQTT API Key
108
109
110
111 )))
112 1. (((
113 [[image:image-20220531140304-12.png]]
114 )))
115
116 == 4.5 Configure LG01 settings ==
117
118 Tips:Please confirm that your LG01 version is 4.3.3.
119
120 [[image:image-20220531140248-11.png]]
121
122 **Overview**
123
124
125
126 [[image:image-20220531140425-14.png]]
127
128 **Senosor->IOT Server**
129
130
131 [[image:image-20220531140458-15.png]]
132
133 **MQTT->Configure MQTT Server**
134
135
136
137 [[image:image-20220531140538-16.png]]
138
139 **MQTT->MQTT Channel**
140
141
142
143 [[image:image-20220531140611-17.png]]
144
145 **Sensor->LoRa/LoraWAN**
146
147
148
149 [[image:image-20220531140651-18.png]]
150
151 Configure network access.**Network->Internet Access**
152
153
154 == 4.6 Try MQTT API call with LG01 Linux command ==
155
156 === 4.6.1 Input the command at the console ===
157
158 1. [[image:image-20220531140811-19.png]](((
159 Open this Application.
160
161
162 )))
163 1. [[image:image-20220531140842-20.png]](((
164 Input passward(dragino).After into the console.
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166
167 )))
168 1. [[image:image-20220531140915-21.png]](((
169 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
170
171
172 )))
173 1. [[image:image-20220531140955-22.png]](((
174 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.
175
176
177
178 )))
179 1. [[image:image-20220531141026-23.png]](((
180 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.
181 )))
182
183 * This command:
184
185 (% class="box infomessage" %)
186 (((
187 **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"**
188 )))
189
190 * Need replace:
191
192 (% class="box infomessage" %)
193 (((
194 **UZ4NGHKJMKS9WR5E  ~/~/MQTT API
195 399171            ~/~/Channel ID
196 A4NNF6G8G63JOIUV  ~/~/Write API Key**
197 )))
198
199
200 === 4.6.2 Input the command at the console(LG01 new version:4.3.4) ===
201
202 1. [[image:image-20220531141150-24.png]](((
203 Open this Application.
204
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206
207 )))
208 1. (((
209 [[image:image-20220531141400-27.png]]
210
211 Check the settings.
212
213
214
215 )))
216 1. (((
217 [[image:image-20220531141601-30.png]]
218
219 input this command.
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223 )))
224 1. [[image:image-20220531141515-29.png]](((
225 Check the result.
226
227
228
229 )))
230
231 == 4.7 Updata data to Server(Through MQTT) ==
232
233 * This version of Sketch implements these features:
234
235 1. Read the LG01 configuration information from Linux.
236 1. Receive the LoRa node data and store the data in the /tmp/iot/channels
237 1. Send reply after then receive LoRa node data.
238 1. Sketch will write active content to /tmp/iot/status periodically (every 5 minutes).(Watchdog feature)
239
240 1. [[image:image-20220531141656-31.png]](((
241 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.
242
243
244
245 )))
246 1. [[image:image-20220531141800-32.png]](((
247 Open Serial monitor.
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250
251 )))
252 1. [[image:image-20220531141842-33.png]](((
253 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.
254
255
256
257 )))
258 1. [[image:image-20220531141927-34.png]](((
259 Open Serial monitor.
260
261
262
263 )))
264 1. Go to IoT Server to check the result.
265 1. (((
266 [[image:image-20220531142023-35.png]]
267
268
269
270 )))
271 1. (((
272 [[image:image-20220531142155-36.png]]
273
274
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276 )))
277
278 = 5. FAQ =
279
280 == 5.1 Configure to support general mqtt server ==
281
282 First, try to run **mosquitto_pub** in Linux console to send a data to MQTT server.
283
284 For example: for ThingSpeak, a MQTT publish command is:
285
286 (% class="box infomessage" %)
287 (((
288 **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"**
289 )))
290
291 What now we need to put in the LG01 is how to combine this command.
292
293 1. LG01 web console -> Sensor -> MQTT
294 1. Choose general Server
295 1. [[image:image-20220531142342-37.png]](((
296 Refer to your server to fill in.
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300 )))
301 1. [[image:image-20220531142447-38.png]](((
302 Ex:ThingSpeak Server
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304
305 )))
306
307 According to MQTT commands: mosquitto_pub, we need to put
308
309 * server[-h] : mqtt.thingspeak.com
310 * port[-p] : 1883
311 * User Name[-u]: dragino
312 * Password[-P]:QZXTAKE88V3S7O2J
313 * Client ID[-i]: dragino_Client
314 * topic_format[-t]: channels/CHANNEL/publish/WRITE_API
315 * data_format[-m]: DATA&status=MQTTPUBLISH
316
317 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.
318
319 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.
320
321 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:
322
323 [[image:image-20220531142525-39.png]]
324
325 MQTT Logread example
326
327
328 == 5.2 What is Watchdog feature? ==
329
330 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.
331
332 * [[image:image-20220531142558-40.png]](((
333 Enable Sensor->Micro-Controller settings
334
335
336
337 )))
338 * [[image:image-20220531142629-41.png]](((
339 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.
340
341
342
343 )))
344 * [[image:image-20220531142659-42.png]](((
345 Each time the function loops, it uses the watchdog function once.
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347
348
349 )))
350 * [[image:image-20220531142720-43.png]](((
351 Open SSH and check watchdog result.If the result change constantly,the feature enable successfully.
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354
355 )))
356 * [[image:image-20220531142748-44.png]](((
357 If the time doesnt's change,you can refer it to calculate for checking status.
358 )))
359
360 (% class="wikigeneratedid" id="H" %)
361