Wiki source code of Through MQTT to upload data

Last modified by Xiaoling on 2022/09/02 18:11
Show last authors
1 **Table of Contents: **
2
3 {{toc/}}
4
5
6
7
8 = 1. What is MQTT API? =
9
10
11 MQTT is a publish/subscribe model that runs over TCP/IP sockets or WebSockets. MQTT over WebSockets can be secured with SSL.
12
13
14
15 = 2. MQTT Features =
16
17
18 The MQTT protocol runs on TCP / IP or other network protocols and provides an ordered, lossless, bidirectional connection. Features include:
19
20 * The publish / subscribe messaging pattern used, which provides one-to-many messaging for decoupling from the application.
21 * Message-masking mechanism for payload content.
22 * There are three Quality of Service (QoS) for transmitting messages:
23 * At most, messages of this level may be lost or duplicated, and message postings depend on the underlying TCP / IP network. That is: <= 1
24 * At one time, this level will ensure that the message arrives, but the message may be repeated. That is:> = 1
25 * 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
26 * Notification mechanism, notify the transmission of both sides when an exception occurs
27
28
29
30
31
32 = 3. What does this example shows? How it works? =
33
34
35 (((
36 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.
37
38
39 )))
40
41 [[image:image-20220531135402-1.png]]
42
43 Message Queuing Telemetry Transport
44
45
46 [[image:image-20220531135449-2.png]]
47
48 working principle
49
50
51
52 [[image:image-20220531135521-3.png]]
53
54 (((
55 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.
56 )))
57
58
59
60 [[image:image-20220531135607-4.png]]
61
62
63 (((
64 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.
65 )))
66
67 (((
68 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.
69 )))
70
71 (((
72 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/]] .
73 )))
74
75
76
77 = 4. Preparation =
78
79
80 == 4.1 Hardware ==
81
82
83 1. [[image:image-20220531135650-5.png]](((
84
85
86 Listening on the LoRa wireless channel, while there is new LoRa packet arrives, parse it and send out to IoT Server.
87
88
89
90 )))
91 1. [[image:image-20220531135750-6.png]](((
92
93
94 The LoRa End node keeps getting temperature and humidity from the sensor and sends out via LoRa periodically.
95
96
97
98 )))
99
100 == 4.2 Software ==
101
102
103 1. [[4.3.4 version>>url:http://www.dragino.com/downloads/index.php?dir=motherboards/ms14/Firmware/IoT/]]
104 1. [[MQTT_Client>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/IoTServer/ThingSpeak/MQTT_Client]]
105 1. [[MQTT_Simple_Server MQTT_Simeple_Server>>url:https://github.com/dragino/Arduino-Profile-Examples/tree/master/libraries/Dragino/examples/LoRa/MQTT_Simple_Server]]
106 1. [[DHTlib>>url:https://github.com/goodcheney/Lora/blob/patch-1/Lora%20Shield/Examples/DHTlib.zip]]
107
108
109
110
111
112 == 4.3 Server(For example) ==
113
114
115 * [[ThingSpeak>>url:https://thingspeak.com/]]
116
117
118
119
120
121 == 4.4 Configure IoT Server ==
122
123
124 * Need this keys:
125
126 1. [[image:image-20220531140054-8.png]](((
127 Channel ID,Write API Key
128
129
130
131 )))
132 1. [[image:image-20220531140326-13.png]](((
133
134
135 Account->My Profile,MQTT API Key
136
137
138
139 )))
140 1. (((
141 [[image:image-20220531140304-12.png]]
142
143
144
145 )))
146
147 == 4.5 Configure LG01 settings ==
148
149
150 Tips:  Please confirm that your LG01 version is 4.3.3.
151
152
153 [[image:image-20220531140248-11.png]]
154
155 **Overview**
156
157
158
159 [[image:image-20220531140425-14.png]]
160
161 **Senosor->IOT Server**
162
163
164
165 [[image:image-20220531140458-15.png]]
166
167 **MQTT->Configure MQTT Server**
168
169
170
171 [[image:image-20220531140538-16.png]]
172
173 **MQTT->MQTT Channel**
174
175
176
177 [[image:image-20220531140611-17.png]]
178
179 **Sensor->LoRa/LoraWAN**
180
181
182
183 [[image:image-20220531140651-18.png]]
184
185
186 Configure network access.**Network->Internet Access**
187
188
189
190 == 4.6 Try MQTT API call with LG01 Linux command ==
191
192
193 === 4.6.1 Input the command at the console ===
194
195
196 1. [[image:image-20220531140811-19.png]](((
197
198
199 Open this Application.
200
201
202
203 )))
204 1. [[image:image-20220531140842-20.png]](((
205
206
207 Input passward(dragino).After into the console.
208
209
210
211 )))
212 1. [[image:image-20220531140915-21.png]](((
213
214
215 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
216
217
218
219 )))
220 1. [[image:image-20220531140955-22.png]](((
221
222
223 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.
224
225
226
227 )))
228 1. [[image:image-20220531141026-23.png]](((
229
230
231 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.
232
233
234 )))
235
236 * This command:
237
238 (% class="box infomessage" %)
239 (((
240 **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"**
241 )))
242
243 * Need replace:
244
245 (% class="box infomessage" %)
246 (((
247 **UZ4NGHKJMKS9WR5E  ~/~/MQTT API
248 399171            ~/~/Channel ID
249 A4NNF6G8G63JOIUV  ~/~/Write API Key**
250 )))
251
252
253
254 === 4.6.2 Input the command at the console(LG01 new version:4.3.4) ===
255
256
257 1. [[image:image-20220531141150-24.png]](((
258
259
260 Open this Application.
261
262
263
264 )))
265 1. (((
266 [[image:image-20220531141400-27.png]]
267
268
269 Check the settings.
270
271
272
273 )))
274 1. (((
275 [[image:image-20220531141601-30.png]]
276
277
278 input this command.
279
280
281
282 )))
283 1. [[image:image-20220531141515-29.png]](((
284
285
286 Check the result.
287
288
289
290 )))
291
292 == 4.7 Updata data to Server(Through MQTT) ==
293
294
295 * This version of Sketch implements these features:
296
297 1. Read the LG01 configuration information from Linux.
298 1. Receive the LoRa node data and store the data in the /tmp/iot/channels
299 1. Send reply after then receive LoRa node data.
300 1. Sketch will write active content to /tmp/iot/status periodically (every 5 minutes).(Watchdog feature)
301
302
303
304 1. [[image:image-20220531143822-49.png]](((
305
306
307 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.
308
309
310
311 )))
312 1. [[image:image-20220531141800-32.png]](((
313
314
315 Open Serial monitor.
316
317
318
319 )))
320 1. [[image:image-20220531143748-48.png]](((
321
322
323 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.
324
325
326
327 )))
328 1. [[image:image-20220531141927-34.png]](((
329
330
331 Open Serial monitor.
332
333
334
335 )))
336 1. Go to IoT Server to check the result.
337 1. (((
338 [[image:image-20220531143707-47.png]]
339
340
341
342 )))
343 1. (((
344 [[image:image-20220531143632-46.png]]
345
346
347
348 )))
349
350 = 5. FAQ =
351
352
353 == 5.1 Configure to support general mqtt server ==
354
355
356 First, try to run **mosquitto_pub** in Linux console to send a data to MQTT server.
357
358 For example: for ThingSpeak, a MQTT publish command is:
359
360 (% class="box infomessage" %)
361 (((
362 **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"**
363 )))
364
365 What now we need to put in the LG01 is how to combine this command.
366
367 1. LG01 web console -> Sensor -> MQTT
368 1. Choose general Server
369 1. [[image:image-20220531142342-37.png]](((
370
371
372 Refer to your server to fill in.
373
374
375
376 )))
377 1. [[image:image-20220531142447-38.png]](((
378
379
380 Ex:ThingSpeak Server
381
382
383 )))
384
385 According to MQTT commands: mosquitto_pub, we need to put
386
387 * server[-h] : mqtt.thingspeak.com
388 * port[-p] : 1883
389 * User Name[-u]: dragino
390 * Password[-P]:QZXTAKE88V3S7O2J
391 * Client ID[-i]: dragino_Client
392 * topic_format[-t]: channels/CHANNEL/publish/WRITE_API
393 * data_format[-m]: DATA&status=MQTTPUBLISH
394
395 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.
396
397 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.
398
399 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:
400
401 [[image:image-20220531142525-39.png]]
402
403
404 MQTT Logread example
405
406
407
408 == 5.2 What is Watchdog feature? ==
409
410
411 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.
412
413
414 * [[image:image-20220531142558-40.png]](((
415 Enable Sensor->Micro-Controller settings
416
417
418
419 )))
420 * [[image:image-20220531142629-41.png]](((
421
422
423 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.
424
425
426
427 )))
428 * [[image:image-20220531142659-42.png]](((
429
430
431 Each time the function loops, it uses the watchdog function once.
432
433
434
435 )))
436 * [[image:image-20220531142720-43.png]](((
437
438
439 Open SSH and check watchdog result.If the result change constantly,the feature enable successfully.
440
441
442
443 )))
444 * [[image:image-20220531142748-44.png]](((
445
446
447 If the time doesnt's change,you can refer it to calculate for checking status.
448 )))
449
450 (% class="wikigeneratedid" id="H" %)
451

Applications

Navigation

Copyright ©2010-2022 Dragino Technology Co., LTD. All rights reserved
Dragino Wiki v2.0