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Wiki source code of Through MQTT to upload data

Version 44.4 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 == 4.4 Configure IoT Server ==
95
96 * Need this keys:
97
98 1. [[image:image-20220531140054-8.png]](((
99 Channel ID,Write API Key
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102
103 )))
104 1. [[image:image-20220531140326-13.png]](((
105 Account->My Profile,MQTT API Key
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107
108
109 )))
110 1. (((
111 [[image:image-20220531140304-12.png]]
112 )))
113
114 == 4.5 Configure LG01 settings ==
115
116 Tips:Please confirm that your LG01 version is 4.3.3.
117
118 [[image:image-20220531140248-11.png]]
119
120 **Overview**
121
122
123
124 [[image:image-20220531140425-14.png]]
125
126 **Senosor->IOT Server**
127
128
129 [[image:image-20220531140458-15.png]]
130
131 **MQTT->Configure MQTT Server**
132
133
134
135 [[image:image-20220531140538-16.png]]
136
137 **MQTT->MQTT Channel**
138
139
140
141 [[image:image-20220531140611-17.png]]
142
143 **Sensor->LoRa/LoraWAN**
144
145
146
147 [[image:image-20220531140651-18.png]]
148
149 Configure network access.**Network->Internet Access**
150
151
152 == 4.6 Try MQTT API call with LG01 Linux command ==
153
154 === 4.6.1 Input the command at the console ===
155
156 1. [[image:image-20220531140811-19.png]](((
157 Open this Application.
158
159
160 )))
161 1. [[image:image-20220531140842-20.png]](((
162 Input passward(dragino).After into the console.
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164
165 )))
166 1. [[image:image-20220531140915-21.png]](((
167 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
168
169
170 )))
171 1. [[image:image-20220531140955-22.png]](((
172 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.
173
174
175
176 )))
177 1. [[image:image-20220531141026-23.png]](((
178 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.
179 )))
180
181 * This command:
182
183 (% class="box infomessage" %)
184 (((
185 **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"**
186 )))
187
188 * Need replace:
189
190 (% class="box infomessage" %)
191 (((
192 **UZ4NGHKJMKS9WR5E  ~/~/MQTT API
193 399171            ~/~/Channel ID
194 A4NNF6G8G63JOIUV  ~/~/Write API Key**
195 )))
196
197
198 === 4.6.2 Input the command at the console(LG01 new version:4.3.4) ===
199
200 1. [[image:image-20220531141150-24.png]](((
201 Open this Application.
202
203
204
205 )))
206 1. (((
207 [[image:image-20220531141400-27.png]]
208
209 Check the settings.
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211
212
213 )))
214 1. (((
215 [[image:image-20220531141601-30.png]]
216
217 input this command.
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220
221 )))
222 1. [[image:image-20220531141515-29.png]](((
223 Check the result.
224
225
226
227 )))
228
229 == 4.7 Updata data to Server(Through MQTT) ==
230
231 * This version of Sketch implements these features:
232
233 1. Read the LG01 configuration information from Linux.
234 1. Receive the LoRa node data and store the data in the /tmp/iot/channels
235 1. Send reply after then receive LoRa node data.
236 1. Sketch will write active content to /tmp/iot/status periodically (every 5 minutes).(Watchdog feature)
237
238 1. [[image:image-20220531141656-31.png]](((
239 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.
240
241
242
243 )))
244 1. [[image:image-20220531141800-32.png]](((
245 Open Serial monitor.
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247
248
249 )))
250 1. [[image:image-20220531141842-33.png]](((
251 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.
252
253
254
255 )))
256 1. [[image:image-20220531141927-34.png]](((
257 Open Serial monitor.
258
259
260
261 )))
262 1. Go to IoT Server to check the result.
263 1. (((
264 [[image:image-20220531142023-35.png]]
265
266
267
268 )))
269 1. (((
270 [[image:image-20220531142155-36.png]]
271
272
273
274 )))
275
276 = 5. FAQ =
277
278 == 5.1 Configure to support general mqtt server ==
279
280 First, try to run **mosquitto_pub** in Linux console to send a data to MQTT server.
281
282 For example: for ThingSpeak, a MQTT publish command is:
283
284 (% class="box infomessage" %)
285 (((
286 **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"**
287 )))
288
289 What now we need to put in the LG01 is how to combine this command.
290
291 1. LG01 web console -> Sensor -> MQTT
292 1. Choose general Server
293 1. [[image:image-20220531142342-37.png]](((
294 Refer to your server to fill in.
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298 )))
299 1. [[image:image-20220531142447-38.png]](((
300 Ex:ThingSpeak Server
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302
303 )))
304
305 According to MQTT commands: mosquitto_pub, we need to put
306
307 * server[-h] : mqtt.thingspeak.com
308 * port[-p] : 1883
309 * User Name[-u]: dragino
310 * Password[-P]:QZXTAKE88V3S7O2J
311 * Client ID[-i]: dragino_Client
312 * topic_format[-t]: channels/CHANNEL/publish/WRITE_API
313 * data_format[-m]: DATA&status=MQTTPUBLISH
314
315 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.
316
317 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.
318
319 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:
320
321 [[image:image-20220531142525-39.png]]
322
323 MQTT Logread example
324
325
326 == 5.2 What is Watchdog feature? ==
327
328 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.
329
330 * [[image:image-20220531142558-40.png]](((
331 Enable Sensor->Micro-Controller settings
332
333
334
335 )))
336 * [[image:image-20220531142629-41.png]](((
337 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.
338
339
340
341 )))
342 * [[image:image-20220531142659-42.png]](((
343 Each time the function loops, it uses the watchdog function once.
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347 )))
348 * [[image:image-20220531142720-43.png]](((
349 Open SSH and check watchdog result.If the result change constantly,the feature enable successfully.
350
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352
353 )))
354 * [[image:image-20220531142748-44.png]](((
355 If the time doesnt's change,you can refer it to calculate for checking status.
356 )))
357
358 (% class="wikigeneratedid" id="H" %)
359