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Version 175.21 by Xiaoling on 2022/06/15 11:08
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1 (% style="text-align:center" %)
2 [[image:1655254599445-662.png]]
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5
6
7 **Table of Contents:**
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15
16 = 1.  Introduction =
17
18 == 1.1 ​ What is LoRaWAN Ultrasonic liquid level Sensor ==
19
20 (((
21
22
23 (((
24 (((
25 (((
26 The Dragino LDDS20 is a (% style="color:#4472c4" %)**LoRaWAN Ultrasonic liquid level sensor**(%%) for Internet of Things solution. It uses (% style="color:#4472c4" %)**none-contact method **(%%)to measure the height of liquid in a container without opening the container, and send the value via LoRaWAN network to IoT Server
27 )))
28
29 (((
30
31 )))
32
33 (((
34 The LDDS20 sensor is installed directly below the container to detect the height of the liquid level. User doesn’t need to open a hole on the container to be tested. The (% style="color:#4472c4" %)**none-contact measurement makes the measurement safety, easier and possible for some strict situation**. 
35 )))
36
37 (((
38
39 )))
40
41 (((
42 LDDS20 uses ultrasonic sensing technology for distance measurement. LDDS20 is of high accuracy to measure various liquid such as: (% style="color:#4472c4" %)**toxic substances**(%%), (% style="color:#4472c4" %)**strong acids**(%%), (% style="color:#4472c4" %)**strong alkalis**(%%) and (% style="color:#4472c4" %)**various pure liquids**(%%) in high-temperature and high-pressure airtight containers.
43 )))
44
45 (((
46
47 )))
48
49 (((
50 The LoRa wireless technology used in LDDS20 allows device to send data and reach extremely long ranges at low data-rates. It provides ultra-long range spread spectrum communication and high interference immunity whilst minimizing current consumption.
51 )))
52
53 (((
54
55 )))
56
57 (((
58 LDDS20 is powered by (% style="color:#4472c4" %)**8500mA Li-SOCI2 battery**(%%); It is designed for long term use up to 10 years*.
59 )))
60
61 (((
62
63 )))
64
65 (((
66 Each LDDS20 pre-loads with a set of unique keys for LoRaWAN registrations, register these keys to local LoRaWAN server and it will auto connect if there is network coverage, after power on.
67 )))
68
69 (((
70
71 )))
72 )))
73
74 (((
75 (((
76 (% style="color:#4472c4" %) * (%%)Actually lifetime depends on network coverage and uplink interval and other factors.
77 )))
78 )))
79 )))
80 )))
81
82
83 [[image:1655255122126-327.png]]
84
85
86
87 == ​1.2  Features ==
88
89 * LoRaWAN 1.0.3 Class A
90 * Ultra low power consumption
91 * Liquid Level Measurement by Ultrasonic technology
92 * Measure through container, No need to contact Liquid.
93 * Valid level range 20mm - 2000mm
94 * Accuracy: ±(5mm+S*0.5%) (S: Measure Value)
95 * Cable Length : 25cm
96 * Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915/IN865
97 * AT Commands to change parameters
98 * Uplink on periodically
99 * Downlink to change configure
100 * IP66 Waterproof Enclosure
101 * 8500mAh Battery for long term use
102
103
104
105
106 == 1.3  Suitable Container & Liquid ==
107
108 * Solid Wall container such as: steel, iron, glass, ceramics, non-foaming plastics etc.
109 * Container shape is regular, and surface is smooth.
110 * Container Thickness:
111 ** Pure metal material.  2~~8mm, best is 3~~5mm
112 ** Pure non metal material: <10 mm
113 * Pure liquid without irregular deposition.
114
115
116
117
118 == 1.4  Mechanical ==
119
120 [[image:image-20220615090910-1.png]]
121
122
123 [[image:image-20220615090910-2.png]]
124
125
126
127 == 1.5  Install LDDS20 ==
128
129
130 (% style="color:blue" %)**Step 1**(%%):  Choose the installation point.
131
132 LDDS20 (% style="color:red" %)**MUST**(%%) be installed on the container bottom middle position.
133
134 [[image:image-20220615091045-3.png]]
135
136
137
138 (% style="color:blue" %)**Step 2**(%%):  Polish the installation point.
139
140 For Metal Surface with paint, it is important to polish the surface, first use crude sand paper to polish the paint level , then use exquisite sand paper to polish the metal level to make it shine & smooth.
141
142 [[image:image-20220615092010-11.png]]
143
144
145 No polish needed if the container is shine metal surface without paint or non-metal container.
146
147 [[image:image-20220615092044-12.png]]
148
149
150
151 (% style="color:blue" %)**Step3:   **(%%)Test the installation point.
152
153 Power on LDDS75, check if the blue LED is on, If the blue LED is on, means the sensor works. Then put ultrasonic coupling paste on the sensor and put it tightly on the installation point.
154
155
156 It is necessary to put the coupling paste between the sensor and the container, otherwise LDDS20 won’t detect the liquid level.
157
158 [[image:1655256160324-178.png]][[image:image-20220615092327-13.png]]
159
160
161 After paste the LDDS20 well, power on LDDS20. In the first 30 seconds of booting, device will check the sensors status and BLUE LED will show the status as below. After 30 seconds, BLUE LED will be off to save battery life.
162
163
164 (% style="color:red" %)**LED Status:**
165
166 * Onboard LED: When power on device, the onboard LED will fast blink 4 times which means detect the sensor well.
167
168 * (% style="color:blue" %)BLUE LED(% style="color:red" %) always ON(%%): Sensor is power on but doesn’t detect liquid. There is problem in installation point.
169 * (% style="color:blue" %)BLUE LED(% style="color:red" %) slowly blinking(%%): Sensor detects Liquid Level, The installation point is good.
170
171 LDDS20 will enter into low power mode at 30 seconds after system reset or power on, Blue LED will be off after that.
172
173
174 (% style="color:red" %)**Note 2:**
175
176 (% style="color:red" %)Ultrasonic coupling paste (%%) is subjected in most shipping way. So the default package doesn’t include it and user needs to purchase locally.
177
178
179
180 (% style="color:blue" %)**Step4:   **(%%)Install use Epoxy ab glue.
181
182 Prepare Eproxy AB glue.
183
184 Put Eproxy AB glue in the sensor and press it hard on the container installation point.
185
186 Reset LDDS20 and see if the BLUE LED is slowly blinking.
187
188 [[image:image-20220615091045-8.png||height="226" width="380"]] [[image:image-20220615091045-9.png||height="239" width="339"]]
189
190
191 (% style="color:red" %)**Note 1:**
192
193 Eproxy AB glue needs 3~~ 5 minutes to stable attached. we can use other glue material to keep it in the position.
194
195
196 (% style="color:red" %)**Note 2:**
197
198 (% style="color:red" %)Eproxy AB glue(%%) is subjected in most shipping way. So the default package doesn’t include it and user needs to purchase locally.
199
200
201
202 == 1.6 ​ Applications ==
203
204 * Smart liquid control solution.
205 * Smart liquefied gas solution.
206
207
208
209
210 == 1.7  Precautions ==
211
212 * At room temperature, containers of different materials, such as steel, glass, iron, ceramics, non-foamed plastics and other dense materials, have different detection blind areas and detection limit heights.
213 * For containers of the same material at room temperature, the detection blind zone and detection limit height are also different for the thickness of the container.
214 * When the detected liquid level exceeds the effective detection value of the sensor, and the liquid level of the liquid to be measured shakes or tilts, the detected liquid height is unstable.
215
216
217
218
219 == 1.8  Pin mapping and power on ==
220
221
222 [[image:1655257026882-201.png]]
223
224
225
226 = 2.  Configure LDDS20 to connect to LoRaWAN network =
227
228
229 == 2.1  How it works ==
230
231 (((
232 The LDDS20 is configured as LoRaWAN OTAA Class A mode by default. It has OTAA keys to join LoRaWAN network. To connect a LoRaWAN network, you need to input the OTAA keys in the LoRaWAN IoT server and power on the LDDS20. If there is coverage of the LoRaWAN network, it will automatically join the network via OTAA and start to send the sensor value.
233 )))
234
235 (((
236 In case you can't set the OTAA keys in the LoRaWAN OTAA server, and you have to use the keys from the server, you can [[use AT Commands >>||anchor="H3.A0UsingtheATCommands"]]to set the keys in the LDDS20.
237 )))
238
239
240
241 == 2.2  ​Quick guide to connect to LoRaWAN server (OTAA) ==
242
243 (((
244 Following is an example for how to join the [[TTN v3 LoRaWAN Network>>url:https://console.cloud.thethings.network/]]. Below is the network structure; we use the [[LG308>>url:http://www.dragino.com/products/lora/item/140-lg308.html]] as a LoRaWAN gateway in this example.
245 )))
246
247 (((
248 [[image:1655257698953-697.png]]
249 )))
250
251 (((
252 The LG308 is already set to connected to [[TTN network >>url:https://console.cloud.thethings.network/]], so what we need to now is configure the TTN server.
253 )))
254
255 (((
256
257
258 (% style="color:blue" %)**Step 1**(%%): Create a device in TTN with the OTAA keys from LDDS20.
259 )))
260
261 (((
262 Each LDDS20 is shipped with a sticker with the default device keys, user can find this sticker in the box. it looks like below.
263 )))
264
265 [[image:image-20220607170145-1.jpeg]]
266
267
268 (((
269 For OTAA registration, we need to set **APP EUI/ APP KEY/ DEV EUI**. Some server might no need to set APP EUI.
270 )))
271
272 (((
273 Enter these keys in the LoRaWAN Server portal. Below is TTN V3 screen shot:
274 )))
275
276 (((
277
278
279 **Add APP EUI in the application**
280 )))
281
282 [[image:image-20220610161353-4.png]]
283
284 [[image:image-20220610161353-5.png]]
285
286 [[image:image-20220610161353-6.png]]
287
288
289 [[image:image-20220610161353-7.png]]
290
291
292
293 You can also choose to create the device manually.
294
295 [[image:image-20220610161538-8.png]]
296
297
298
299 **Add APP KEY and DEV EUI**
300
301 [[image:image-20220610161538-9.png]]
302
303
304
305 (% style="color:blue" %)**Step 2**(%%):  Power on LDDS20
306
307
308 Put a Jumper on JP2 to power on the device. ( The Switch must be in FLASH position).
309
310 [[image:image-20220615095102-14.png]]
311
312
313
314 (((
315 (% style="color:blue" %)**Step 3**(%%)**:**  The LDDS20 will auto join to the TTN network. After join success, it will start to upload messages to TTN and you can see the messages in the panel.
316 )))
317
318 [[image:1654849068701-275.png]]
319
320
321
322 == 2.3  ​Uplink Payload ==
323
324 (((
325 (((
326 LDDS20 will uplink payload via LoRaWAN with below payload format: 
327
328 Uplink payload includes in total 8 bytes.
329 Payload for firmware version v1.1.4. . Before v1.1.3, there is only 5 bytes: BAT and Distance(Please check manual v1.2.0 if you have 5 bytes payload).
330 )))
331 )))
332
333 (((
334
335 )))
336
337 (% border="1" cellspacing="10" style="background-color:#ffffcc; width:510px" %)
338 |=(% style="width: 62.5px;" %)(((
339 **Size (bytes)**
340 )))|=(% style="width: 62.5px;" %)**2**|=**2**|=1|=2|=**1**
341 |(% style="width:62.5px" %)**Value**|(% style="width:62.5px" %)[[BAT>>||anchor="H2.3.1A0BatteryInfo"]]|(((
342 [[Distance>>||anchor="H2.3.2A0Distance"]]
343
344 (unit: mm)
345 )))|[[Digital Interrupt (Optional)>>||anchor="H2.3.3A0InterruptPin"]]|(((
346 [[Temperature (Optional )>>||anchor="H2.3.4A0DS18B20Temperaturesensor"]]
347 )))|[[Sensor Flag>>||anchor="H2.3.5A0SensorFlag"]]
348
349 [[image:1654850511545-399.png]]
350
351
352
353 === 2.3.1  Battery Info ===
354
355
356 Check the battery voltage for LDDS20.
357
358 Ex1: 0x0B45 = 2885mV
359
360 Ex2: 0x0B49 = 2889mV
361
362
363
364 === 2.3.2  Distance ===
365
366 (((
367 Get the distance. Flat object range 20mm - 2000mm.
368 )))
369
370 (((
371 For example, if the data you get from the register is __0x06 0x05__, the distance between the sensor and the measured object is(% style="color:#4472c4" %)** 0605(H) = 1541 (D) = 1541 mm.**
372 )))
373
374 * If the sensor value is 0x0000, it means system doesn't detect ultrasonic sensor.
375 * If the sensor value lower than 0x0014 (20mm), the sensor value will be invalid.
376
377 === 2.3.3  Interrupt Pin ===
378
379 This data field shows if this packet is generated by interrupt or not. [[Click here>>||anchor="H3.2A0SetInterruptMode"]] for the hardware and software set up.
380
381 **Example:**
382
383 0x00: Normal uplink packet.
384
385 0x01: Interrupt Uplink Packet.
386
387
388
389 === 2.3.4  DS18B20 Temperature sensor ===
390
391 This is optional, user can connect external DS18B20 sensor to the +3.3v, 1-wire and GND pin . and this field will report temperature.
392
393 **Example**:
394
395 If payload is: 0105H:  (0105 & FC00 == 0), temp = 0105H /10 = 26.1 degree
396
397 If payload is: FF3FH :  (FF3F & FC00 == 1) , temp = (FF3FH - 65536)/10 = -19.3 degrees.
398
399 (% style="color:red" %)Note: DS18B20 feature is supported in the hardware version > v1.3 which made since early of 2021.
400
401
402
403 === 2.3.5  Sensor Flag ===
404
405 (((
406 0x01: Detect Ultrasonic Sensor
407 )))
408
409 (((
410 0x00: No Ultrasonic Sensor
411 )))
412
413
414
415 === 2.3.6  Decode payload in The Things Network ===
416
417 While using TTN network, you can add the payload format to decode the payload.
418
419
420 [[image:1655261164557-670.png]]
421
422 The payload decoder function for TTN V3 is here:
423
424 (((
425 LDDS20 TTN V3 Payload Decoder: [[http:~~/~~/www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LDDS20/Payload_Decoder/>>url:http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LSE01/Payload_Decoder/]]
426 )))
427
428
429
430 == 2.4  Downlink Payload ==
431
432 By default, LDDS20 prints the downlink payload to console port.
433
434 [[image:image-20220615100930-15.png]]
435
436
437 **Examples:**
438
439
440 * (% style="color:blue" %)**Set TDC**
441
442 If the payload=0100003C, it means set the END Node's TDC to 0x00003C=60(S), while type code is 01.
443
444 Payload:    01 00 00 1E    TDC=30S
445
446 Payload:    01 00 00 3C    TDC=60S
447
448
449 * (% style="color:blue" %)**Reset**
450
451 If payload = 0x04FF, it will reset the LDDS20
452
453
454 * (% style="color:blue" %)**CFM**
455
456 Downlink Payload: 05000001, Set AT+CFM=1 or 05000000 , set AT+CFM=0
457
458
459
460 == 2.5  ​Show Data in DataCake IoT Server ==
461
462 (((
463 [[DATACAKE>>url:https://datacake.co/]] provides a human friendly interface to show the sensor data, once we have data in TTN, we can use [[DATACAKE>>url:https://datacake.co/]] to connect to TTN and see the data in DATACAKE. Below are the steps:
464 )))
465
466 (((
467
468 )))
469
470 (((
471 (% style="color:blue" %)**Step 1**(%%)**: Be sure that your device is programmed and properly connected to the network at this time.**
472 )))
473
474 (((
475 (% style="color:blue" %)**Step 2**(%%)**: To configure the Application to forward data to DATACAKE you will need to add integration. To add the DATACAKE integration, perform the following steps:**
476 )))
477
478
479 [[image:1654592790040-760.png]]
480
481
482 [[image:1654592800389-571.png]]
483
484
485 (% style="color:blue" %)**Step 3**(%%)**: Create an account or log in Datacake.**
486
487 (% style="color:blue" %)**Step 4**(%%)**: Search the LDDS75 and add DevEUI.(% style="color:red" %)(Note: LDDS20 use same payload as LDDS75)(%%)**
488
489 [[image:1654851029373-510.png]]
490
491
492 After added, the sensor data arrive TTN V3, it will also arrive and show in Datacake.
493
494 [[image:image-20220610165129-11.png||height="595" width="1088"]]
495
496
497
498 == 2.6  LED Indicator ==
499
500 The LDDS20 has an internal LED which is to show the status of different state.
501
502
503 * Blink once when device power on.
504 * The device detects the sensor and flashes 5 times.
505 * Solid ON for 5 seconds once device successful Join the network.
506 * Blink once when device transmit a packet.
507
508 == 2.7  ​Firmware Change Log ==
509
510
511 (((
512 **Firmware download link:  **[[http:~~/~~/www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LSE01/Firmware/>>url:http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LSE01/Firmware/]]
513 )))
514
515 (((
516
517 )))
518
519 (((
520 **Firmware Upgrade Method:  [[Firmware Upgrade Instruction>>doc:Main.Firmware Upgrade Instruction for STM32 base products.WebHome]]**
521 )))
522
523
524
525 == 2.8  Battery Analysis ==
526
527
528
529
530 === 2.8.1  Battery Type ===
531
532 The LDDS20 battery is a combination of a 8500mAh Li/SOCI2 Battery and a Super Capacitor. The battery is non-rechargeable battery type with a low discharge rate (<2% per year). This type of battery is commonly used in IoT devices such as water meter.
533
534
535 The battery related documents as below:
536
537 * (((
538 [[Battery Dimension>>https://www.dragino.com/downloads/index.php?dir=datasheet/Battery/ER26500/]],
539 )))
540 * (((
541 [[Lithium-Thionyl Chloride Battery  datasheet>>https://www.dragino.com/downloads/index.php?dir=datasheet/Battery/ER26500/]],
542 )))
543 * (((
544 [[Lithium-ion Battery-Capacitor datasheet>>https://www.dragino.com/downloads/index.php?dir=datasheet/Battery/ER26500/]]
545 )))
546
547 [[image:image-20220615102527-16.png]]
548
549
550
551 == 2.8.2  Battery Note ==
552
553 The Li-SICO battery is designed for small current / long period application. It is not good to use a high current, short period transmit method. The recommended minimum period for use of this battery is 5 minutes. If you use a shorter period time to uplink data, then the battery life may be decreased.
554
555
556
557 === 2.8.3  Replace the battery ===
558
559 (((
560 You can change the battery in the LDDS75.The type of battery is not limited as long as the output is between 3v to 3.6v. On the main board, there is a diode (D1) between the battery and the main circuit. If you need to use a battery with less than 3.3v, please remove the D1 and shortcut the two pads of it so there won't be voltage drop between battery and main board.
561 )))
562
563 (((
564
565 )))
566
567 (((
568 The default battery pack of LDDS75 includes a ER18505 plus super capacitor. If user can't find this pack locally, they can find ER18505 or equivalence, which will also work in most case. The SPC can enlarge the battery life for high frequency use (update period below 5 minutes)
569 )))
570
571
572
573 == 2.8.4  Battery Life Analyze ==
574
575 Dragino battery powered products are all run in Low Power mode. User can check the guideline from this link to calculate the estimate battery life:
576
577 [[https:~~/~~/www.dragino.com/downloads/downloads/LoRa_End_Node/Battery_Analyze/DRAGINO_Battery_Life_Guide.pdf>>url:https://www.dragino.com/downloads/downloads/LoRa_End_Node/Battery_Analyze/DRAGINO_Battery_Life_Guide.pdf]]
578
579
580
581 = 3.  Using the AT Commands =
582
583 (((
584 (((
585
586 )))
587 )))
588
589 == 3.1  Access AT Commands ==
590
591 LDDS20 supports AT Command set in the stock firmware. You can use a USB to TTL adapter to connect to LDDS20 for using AT command, as below.
592
593
594 [[image:image-20220610172924-4.png||height="483" width="988"]]
595
596
597 Or if you have below board, use below connection:
598
599
600 [[image:image-20220610172924-5.png]]
601
602
603 (((
604 In the PC, you need to set the serial baud rate to (% style="color:green" %)**9600**(%%) to access the serial console for LDDS20. LDDS20 will output system info once power on as below:
605 )))
606
607
608 [[image:image-20220610172924-6.png||height="601" width="860"]]
609
610 Below are the available commands, a more detailed AT Command manual can be found at [[AT Command Manual>>https://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LSE01/]].
611
612
613 AT+<CMD>?  :  Help on <CMD>
614
615 AT+<CMD>  :  Run <CMD>
616
617 AT+<CMD>=<value>  :  Set the value
618
619 AT+<CMD>=?  :  Get the value
620
621
622 (% style="color:#037691" %)** General Commands :**     
623
624 AT  :  Attention       
625
626 AT?  :  Short Help     
627
628 ATZ :  MCU Reset    
629
630 AT+TDC :  Application Data Transmission Interval 
631
632
633 (% style="color:#037691" %)** Keys, IDs and EUIs management :**
634
635 AT+APPEUI  :  Application EUI      
636
637 AT+APPKEY  :  Application Key     
638
639 AT+APPSKEY  :  Application Session Key
640
641 AT+DADDR :  Device Address     
642
643 AT+DEUI :  Device EUI     
644
645 AT+NWKID  :  Network ID (You can enter this command change only after successful network connection) 
646
647 AT+NWKSKEY  : Network Session Key Joining and sending date on LoRa network  
648
649 AT+CFM :  Confirm Mode       
650
651 AT+CFS :  Confirm Status       
652
653 AT+JOIN  :  Join LoRa? Network       
654
655 AT+NJM  :  LoRa? Network Join Mode    
656
657 AT+NJS  :  LoRa? Network Join Status    
658
659 AT+RECV  :  Print Last Received Data in Raw Format
660
661 AT+RECVB :  Print Last Received Data in Binary Format      
662
663 AT+SEND  :  Send Text Data      
664
665 AT+SENB  :  Send Hexadecimal Data
666
667
668 (% style="color:#037691" %)** LoRa Network Management :**
669
670 AT+ADR  :  Adaptive Rate
671
672 AT+CLASS  :  LoRa Class(Currently only support class A
673
674 AT+DCS  :  Duty Cycle Setting 
675
676 AT+DR  :  Data Rate (Can Only be Modified after ADR=0)     
677
678 AT+FCD  :  Frame Counter Downlink       
679
680 AT+FCU  :  Frame Counter Uplink   
681
682 AT+JN1DL  :  Join Accept Delay1
683
684 AT+JN2DL  :  Join Accept Delay2
685
686 AT+PNM  :  Public Network Mode   
687
688 AT+RX1DL  :  Receive Delay1      
689
690 AT+RX2DL  :  Receive Delay2      
691
692 AT+RX2DR  :  Rx2 Window Data Rate 
693
694 AT+RX2FQ  :  Rx2 Window Frequency
695
696 AT+TXP  :  Transmit Power
697
698
699 (% style="color:#037691" %)** Information :**
700
701 AT+RSSI  :  RSSI of the Last Received Packet   
702
703 AT+SNR  :  SNR of the Last Received Packet   
704
705 AT+VER  :  Image Version and Frequency Band       
706
707 AT+FDR  :  Factory Data Reset
708
709 AT+PORT  :  Application Port    
710
711 AT+CHS  :  Get or Set Frequency (Unit: Hz) for Single Channel Mode
712
713 AT+CHE  :  Get or Set eight channels mode, Only for US915, AU915, CN470
714
715
716
717 == 3.2  Set Interrupt Mode ==
718
719 Feature, Set Interrupt mode for GPIO_EXIT.
720
721 (% style="color:#037691" %)**Downlink Command: AT+INTMOD**
722
723 [[image:image-20220610174917-9.png]]
724
725
726 (% style="color:#037691" %)**Downlink Command: 0x06**
727
728 Format: Command Code (0x06) followed by 3 bytes.
729
730 (((
731 This means that the interrupt mode of the end node is set to 0x000003=3 (rising edge trigger), and the type code is 06.
732 )))
733
734 * Example 1: Downlink Payload: 06000000 ~/~/ Turn off interrupt mode
735 * Example 2: Downlink Payload: 06000003 ~/~/ Set the interrupt mode to rising edge trigger
736
737
738
739 = 4.  FAQ =
740
741 == 4.1  What is the frequency plan for LDDS20? ==
742
743 LDDS20 use the same frequency as other Dragino products. User can see the detail from this link:  [[Introduction>>doc:Main.End Device Frequency Band.WebHome||anchor="H1.Introduction"]]
744
745
746
747 == 4.2  How to change the LoRa Frequency Bands/Region ==
748
749 You can follow the instructions for [[how to upgrade image>>||anchor="H2.7A0200BFirmwareChangeLog"]].
750 When downloading the images, choose the required image file for download. ​
751
752
753
754 = 5.  Trouble Shooting =
755
756 == 5.1  Why I can’t join TTN V3 in US915 / AU915 bands? ==
757
758 It is due to channel mapping. Please see below link:  [[Frequency band>>doc:Main.LoRaWAN Communication Debug.WebHome||anchor="H2.NoticeofUS9152FCN4702FAU915Frequencyband"]]
759
760
761 == 5.2  AT Command input doesn't work ==
762
763 In the case if user can see the console output but can’t type input to the device. Please check if you already include the (% style="color:green" %)**ENTER**(%%) while sending out the command. Some serial tool doesn’t send (% style="color:green" %)**ENTER**(%%) while press the send key, user need to add ENTER in their string.
764
765 (((
766
767 )))
768
769
770 = 6.  Order Info =
771
772
773 Part Number **:** (% style="color:blue" %)**LDDS20-XX**
774
775
776 (% style="color:blue" %)**XX**(%%)**: **The default frequency band
777
778 * (% style="color:red" %)**AS923 **(%%)**:** LoRaWAN AS923 band
779 * (% style="color:red" %)**AU915 **(%%)**:** LoRaWAN AU915 band
780 * (% style="color:red" %)**EU433 **(%%)**:** LoRaWAN EU433 band
781 * (% style="color:red" %)**EU868 **(%%)**:** LoRaWAN EU868 band
782 * (% style="color:red" %)**KR920 **(%%)**:** LoRaWAN KR920 band
783 * (% style="color:red" %)**US915 **(%%)**:** LoRaWAN US915 band
784 * (% style="color:red" %)**IN865 **(%%)**:**  LoRaWAN IN865 band
785 * (% style="color:red" %)**CN470 **(%%)**:** LoRaWAN CN470 band
786
787
788 = 7. ​ Packing Info =
789
790
791 **Package Includes**:
792
793 * LDDS20 LoRaWAN Liquid Level Sensor x 1
794
795
796 (% style="color:red" %)**Note:**
797
798 (% style="color:red" %)**Ultrasonic coupling paste**(%%) and(% style="color:red" %)** Eproxy AB glue**(%%) are subjected in most shipping way. So the default package doesn’t include it and user needs to purchase locally.
799
800
801 **Dimension and weight**:
802
803 * Device Size: cm
804 * Device Weight: g
805 * Package Size / pcs : cm
806 * Weight / pcs : g
807
808
809 = 8.  ​Support =
810
811 * Support is provided Monday to Friday, from 09:00 to 18:00 GMT+8. Due to different timezones we cannot offer live support. However, your questions will be answered as soon as possible in the before-mentioned schedule.
812 * Provide as much information as possible regarding your enquiry (product models, accurately describe your problem and steps to replicate it etc) and send a mail to [[support@dragino.com>>url:http://../../../../../../D:%5C%E5%B8%82%E5%9C%BA%E8%B5%84%E6%96%99%5C%E8%AF%B4%E6%98%8E%E4%B9%A6%5CLoRa%5CLT%E7%B3%BB%E5%88%97%5Csupport@dragino.com]].