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Wiki source code of Through MQTT to upload data

Version 44.3 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 == 4.3 Server(For example) ==
89
90 * [[ThingSpeak>>url:https://thingspeak.com/]]
91
92 == 4.4 Configure IoT Server ==
93
94 * Need this keys:
95
96 1. [[image:image-20220531140054-8.png]](((
97 Channel ID,Write API Key
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100
101 )))
102 1. [[image:image-20220531140326-13.png]](((
103 Account->My Profile,MQTT API Key
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107 )))
108 1. (((
109 [[image:image-20220531140304-12.png]]
110 )))
111
112 == 4.5 Configure LG01 settings ==
113
114 Tips:Please confirm that your LG01 version is 4.3.3.
115
116 [[image:image-20220531140248-11.png]]
117
118 **Overview**
119
120
121
122 [[image:image-20220531140425-14.png]]
123
124 **Senosor->IOT Server**
125
126
127 [[image:image-20220531140458-15.png]]
128
129 **MQTT->Configure MQTT Server**
130
131
132
133 [[image:image-20220531140538-16.png]]
134
135 **MQTT->MQTT Channel**
136
137
138
139 [[image:image-20220531140611-17.png]]
140
141 **Sensor->LoRa/LoraWAN**
142
143
144
145 [[image:image-20220531140651-18.png]]
146
147 Configure network access.**Network->Internet Access**
148
149
150 == 4.6 Try MQTT API call with LG01 Linux command ==
151
152 === 4.6.1 Input the command at the console ===
153
154 1. [[image:image-20220531140811-19.png]](((
155 Open this Application.
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157
158 )))
159 1. [[image:image-20220531140842-20.png]](((
160 Input passward(dragino).After into the console.
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162
163 )))
164 1. [[image:image-20220531140915-21.png]](((
165 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
166
167
168 )))
169 1. [[image:image-20220531140955-22.png]](((
170 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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172
173
174 )))
175 1. [[image:image-20220531141026-23.png]](((
176 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.
177 )))
178
179 * This command:
180
181 (% class="box infomessage" %)
182 (((
183 **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"**
184 )))
185
186 * Need replace:
187
188 (% class="box infomessage" %)
189 (((
190 **UZ4NGHKJMKS9WR5E  ~/~/MQTT API
191 399171            ~/~/Channel ID
192 A4NNF6G8G63JOIUV  ~/~/Write API Key**
193 )))
194
195
196 === 4.6.2 Input the command at the console(LG01 new version:4.3.4) ===
197
198 1. [[image:image-20220531141150-24.png]](((
199 Open this Application.
200
201
202
203 )))
204 1. (((
205 [[image:image-20220531141400-27.png]]
206
207 Check the settings.
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211 )))
212 1. (((
213 [[image:image-20220531141601-30.png]]
214
215 input this command.
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219 )))
220 1. [[image:image-20220531141515-29.png]](((
221 Check the result.
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223
224
225 )))
226
227 == 4.7 Updata data to Server(Through MQTT) ==
228
229 * This version of Sketch implements these features:
230
231 1. Read the LG01 configuration information from Linux.
232 1. Receive the LoRa node data and store the data in the /tmp/iot/channels
233 1. Send reply after then receive LoRa node data.
234 1. Sketch will write active content to /tmp/iot/status periodically (every 5 minutes).(Watchdog feature)
235
236 1. [[image:image-20220531141656-31.png]](((
237 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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241 )))
242 1. [[image:image-20220531141800-32.png]](((
243 Open Serial monitor.
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247 )))
248 1. [[image:image-20220531141842-33.png]](((
249 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.
250
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252
253 )))
254 1. [[image:image-20220531141927-34.png]](((
255 Open Serial monitor.
256
257
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259 )))
260 1. Go to IoT Server to check the result.
261 1. (((
262 [[image:image-20220531142023-35.png]]
263
264
265
266 )))
267 1. (((
268 [[image:image-20220531142155-36.png]]
269
270
271
272 )))
273
274 = 5. FAQ =
275
276 == 5.1 Configure to support general mqtt server ==
277
278 First, try to run **mosquitto_pub** in Linux console to send a data to MQTT server.
279
280 For example: for ThingSpeak, a MQTT publish command is:
281
282 (% class="box infomessage" %)
283 (((
284 **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"**
285 )))
286
287 What now we need to put in the LG01 is how to combine this command.
288
289 1. LG01 web console -> Sensor -> MQTT
290 1. Choose general Server
291 1. [[image:image-20220531142342-37.png]](((
292 Refer to your server to fill in.
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296 )))
297 1. [[image:image-20220531142447-38.png]](((
298 Ex:ThingSpeak Server
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300
301 )))
302
303 According to MQTT commands: mosquitto_pub, we need to put
304
305 * server[-h] : mqtt.thingspeak.com
306 * port[-p] : 1883
307 * User Name[-u]: dragino
308 * Password[-P]:QZXTAKE88V3S7O2J
309 * Client ID[-i]: dragino_Client
310 * topic_format[-t]: channels/CHANNEL/publish/WRITE_API
311 * data_format[-m]: DATA&status=MQTTPUBLISH
312
313 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.
314
315 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.
316
317 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:
318
319 [[image:image-20220531142525-39.png]]
320
321 MQTT Logread example
322
323
324 == 5.2 What is Watchdog feature? ==
325
326 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.
327
328 * [[image:image-20220531142558-40.png]](((
329 Enable Sensor->Micro-Controller settings
330
331
332
333 )))
334 * [[image:image-20220531142629-41.png]](((
335 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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337
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339 )))
340 * [[image:image-20220531142659-42.png]](((
341 Each time the function loops, it uses the watchdog function once.
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345 )))
346 * [[image:image-20220531142720-43.png]](((
347 Open SSH and check watchdog result.If the result change constantly,the feature enable successfully.
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351 )))
352 * [[image:image-20220531142748-44.png]](((
353 If the time doesnt's change,you can refer it to calculate for checking status.
354 )))
355
356 (% class="wikigeneratedid" id="H" %)
357