Skip to Content

Wiki source code of LoRaWAN Communication Debug

Version 30.4 by Xiaoling on 2022/05/30 10:58
Show last authors
1 **~ Contents:**
2
3 {{toc/}}
4
5
6
7 = 1. OTAA Join Process Debug =
8
9 These pages are useful to check what is wrong on the Join process. Below shows the four steps that we can check the Join Process.
10 \\**If user has checked below steps and still can't solve the problem, please send us (support @ dragino.com) the sceenshots for each step to check. They include:**
11
12 * End node console to show the Join freuqency and DR. (If possible)
13 * Gateway (from gateway UI) traffic to show the packet got from end node and receive from Server. (If possible)
14 * Gateway traffic (from server UI) to shows the data exchange between gateway and server. (Normaly possible)
15 * End Node traffic (from server UI) to shows end node activity in server. (Normaly possible)
16 * End Node Keys screen shot shows in end node and server. so we can check if the keys are correct. (In most case, we found keys doesn't match, especially APP EUI)
17
18 **~1. End Device Join Screen shot, we can check:**
19
20 * If the device is sending join request to server?
21 * What frequency the device is sending?
22
23 [[image:image-20220526164956-15.png]]
24
25 Console Output from End device to see the transmit frequency
26
27
28 **2. Gateway packet traffic in gateway web or ssh. we can check:**
29
30 * If the gateway receive the Join request packet from sensor? (If this fail, check if the gateway and sensor works on the match frequency)
31 * If the gateway gets the Join Accept message from server and transmit it via LoRa?
32
33 [[image:image-20220526163608-2.png]]
34
35 Console Output from Gateway to see packets between end node and server.
36
37
38 **3. Gateway Traffic Page in LoRaWAN Server**
39
40 * If the Join Request packet arrive the gateway traffic in server? If not, check the internet connection and gateway LoRaWAN server settings.
41 * If the server send back a Join Accept for the Join Request? if not, check if the keys from the device match the keys you put in the server, or try to choose a different server route for this end device.
42 * If the Join Accept message are in correct frequency? If you set the server to use US915 band, and your end node and gateway is EU868, you will see the Join Accept message are in US915 band so no possible to Join success.
43
44 [[image:image-20220526163633-3.png]]
45
46 The Traffic for the End node in the server, use TTN as example
47
48
49 **4. Data Page in LoRaWAN server**
50
51 * If this data page shows the Join Request message from the end node? If not, most properly you have wrong settings in the keys. Keys in the server doesn't match the keys in End Node.
52
53 [[image:image-20220526163704-4.png]]
54
55 The data for the end device set in server
56
57 [[image:image-20220526163732-5.png]]
58
59 Check if OTAA Keys match the keys in device
60
61
62 = 2. Notice of US915/CN470/AU915 Frequency band =
63
64 (((
65 If user has problem to work with lorawan server in band US915/AU915/CN470, he can check:
66 )))
67
68 * (((
69 What **sub-band** the server support ?
70 )))
71 * (((
72 What is the **sub-band** the gateway support ?
73 )))
74 * (((
75 What is the **sub-band** the end node is using ?
76 )))
77
78 (((
79 All of above should match so End Node can properly Join the server and don't have packet lost.
80 )))
81
82 (((
83
84 )))
85
86 (((
87 In LoRaWAN protocol, the frequency bands US915, AU915, CN470 each includes at least 72 frequencies. Many gateways support only 8 or 16 frequencies, and server might support 8 frequency only. In this case, the OTAA join time and uplink schedule is long and unpredictable while the end node is hopping in 72 frequencies, because the end node will send data in many frequency that the gateway or server doesn,t support.
88 )))
89
90 (((
91
92 )))
93
94 (((
95 Here are the freuqency tables for these bands as reference:
96 )))
97
98 [[image:image-20220526163801-6.png]]
99
100 US915 Channels
101
102 [[image:image-20220526163926-7.png]]
103
104 AU915 Channels
105
106 [[image:image-20220526163941-8.png]]
107
108 (((
109 CN470 Channels
110 )))
111
112 (((
113 If we look at the [[TTN network server frequency plan>>url:https://www.thethingsnetwork.org/docs/lorawan/frequency-plans.html]], we can see the US915 frequency band use the channel 8~~15.So the End Node must work at the same frequency in US915 8~~15 channels for TTN server.
114 )))
115
116 [[image:image-20220526164052-9.png]]
117
118 (((
119 TTN FREQUENCY PLAN
120 )))
121
122 (((
123 In dragino end node, user can use AT+CHE command to set what frequencies set the end node will use. The default settings for Dragino end node are preconfigure for TTN server, so use 8~~15 channels, which is **AT+CHE=2**. (AT+CHE=1 for first 8 channels, AT+CHE=2 for second 8 channels.. etc, and AT+CHE=0 for all 72 channels. )
124 )))
125
126
127 = 3. Why i see data lost/unperiocially uplink data? Even the signal strength is good =
128
129 In this case, we can check if the frequency band matches in End Node, Gateway and LoRaWAN server. A typical case is using US915 in ChirpStack server as below:
130
131 * **End node** ~-~-> Use Sub-band2 (Channel 8,9,10,11,12,13,14,15) for Dragino Sensor. ADR is also enable, this is the default settings for dragino sensors.
132 * **Gateway** ~-~-> Use Sub-band2 (Channel 8,9,10,11,12,13,14,15) for Dragino Gateway. this is the default settings for dragino sensors.
133 * **LoRaWAN server** ~-~-> ChirpStack default installation and use Sub-band1, **enabled_uplink_channels=[0, 1, 2, 3, 4, 5, 6, 7]** in the file chirpstack-network-server.toml.
134
135 (((
136 When Sensor power on, it will use sub-band2 to join the network, the frequency matches the settings in gateway so all Join Request will be passed to the server for Join. Server will ask the sensor to change to Sub-band1 in the Join Accept downlink message. Sensor will change to sub-band1 for data upload. This cause the sensor and gateway have different frequencies so user see lost of most data or even no data.
137 )))
138
139 (((
140
141 )))
142
143 (((
144 Use Subband2 as a default subband cause the sensor to have problem to work with the LoRaWAN server which use other subband, and use need to access to the end node to change the subband by console. that is not user frendily,. So since Dragino LoRaWAN Stack version DLS-005(release on end of 2020), we have changed the device to use All Subbands for OTAA join, for example, device will use the first frequency in Sub-Band1 as firt OTAA join packet, then use the first frequency in Sub-Band 2 , then first frequency in sub-band 3, and so on. LoRaWAN server will normally provide the required subband in the OTAA accept process, so end node will know what subband it use after join. If LoRaWAN server doesn't provide subband info in OTAA join, end node will use the subband which join success as the working subband. So the new method cause a longer OTAA Join time but will be compatible with all LoRaWAN server. And new method won't affect the normal uplink after Join Success.
145 )))
146
147
148 = 4. Transmision on ABP Mode =
149
150 (((
151 In ABP mode, there is a Frame Counter Checks. With this check enabled, the server will only accept the frame with a higher counter. If you reboot the device in ABP mode, the device will start from count 0, so you won't be able to see the frame update in server.
152 )))
153
154 (((
155
156 )))
157
158 (((
159 So in ABP mode, first check if the packet already arrive your gateway, if the packet arrive gatewat but didn't arrive server. Please check if this is the issue.
160 )))
161
162 (((
163
164 )))
165
166 (((
167 To solve this, disable the Frame Counter Check will solve this issue , or reset the frame counter in the device page.
168 )))
169
170 [[image:image-20220526164508-10.png]]
171
172 Disable Frame Counter Check in ABP Mode
173
174
175 = 5. Downstream Debug =
176
177 == 5.1 How it work ==
178
179 LoRaWAN End node will open two receive windows to receive the downstream data. If the downstream packets arrive the end node at these receive windows, the end node will be able to get this packet and process it.
180
181 (((
182 Depends on Class A or Class C, the receive windows will be a little difference,
183 )))
184
185 [[image:image-20220526164547-11.png]]
186
187 receive windows for Class A and Class C
188
189 Below are the requirement for the End Device to receive the packets.
190
191 * The End Device must open the receive windows: RX1 or RX2
192 * The LoRaWAN server must send a downstream packet, and the gateway forward this downstream packet for this end node.
193 * This downstream packet must arrive to the end node while RX1 or RX2 is open.
194 * This packet must match the frequency of the RX1 or RX2 window.
195 * This packet must match the DataRate of RX1(RX1DR) or RX2 (RX2DR). **This is the common fail point, because different lorawan server might use different RX2DR and they don't info End Node via ADR message so cause the mismatch. If this happen, user need to change the RX2DR to the right value in end node. In OTAA, LoRaWAN Server will send the RX2DR setting in Join Accept message so the end node will auto adjust. but ABP uplink doesn't support this auto change.**
196
197
198
199 == 5.2 See Debug Info ==
200
201 (((
202 **For LoRaWAN Server**
203 )))
204
205 (((
206 We can check if there is downlink message for this end node, use TTN for example:
207 )))
208
209 (((
210 Configure a downstream to the end device
211 )))
212
213 [[image:image-20220526164623-12.png]]
214
215 (((
216 Set a downstream in TTN and see it is sent
217 )))
218
219
220 (((
221 This downstream info will then pass to the gateway downstream list. and include the DR which is used (SF9BW125) in EU868 is DR3
222 )))
223
224 [[image:image-20220526164650-13.png]]
225
226 (((
227 Gateway Traffic can see this downstream info
228 )))
229
230
231 (((
232 **For LoRaWAN Gateway**
233 )))
234
235 (((
236 When the downstream packet appear on the traffic of Gateway page. The LoRaWAN gateway can get it from LoRaWAN server and transmit it. In Dragion Gateway, this can be checked by runinng "logread -f" in the SSH console. and see below:
237 )))
238
239 [[image:image-20220526164734-14.png]]
240
241 (((
242 Gateway Sent out this packet
243 )))
244
245
246 (((
247 **For End Node**
248 )))
249
250 (((
251 we can use AT Command (AT+CFG) to check the RX1 configure and RX2 configure. as below:
252 )))
253
254 (((
255
256 )))
257
258 (((
259 (% class="box infomessage" %)
260 (((
261 AT+RX2FQ=869525000     ~-~--> The RX2 Window frequency
262 AT+RX2DR=3      ~-~--> The RX2 DataRate
263 AT+RX1DL=1000   ~-~--> Receive Delay 1
264 AT+RX2DL=2000   ~-~--> Receive Delay 2
265 )))
266 )))
267
268 (((
269 **when the device running, we can see below info:**
270 )))
271
272 {{{ [12502]***** UpLinkCounter= 0 *****
273 [12503]TX on freq 868500000 Hz at DR 0
274 [13992]txDone
275 [15022]RX on freq 868500000 Hz at DR 0 --> RX1 window open at frequency: 868500000, DR0, after 15022-13992= 1030ms of txdone
276 [15222]rxTimeOut --> no packet arrive in RX1 window. (duration: 200ms)
277 [15987]RX on freq 869525000 Hz at DR 3 --> RX2 window open at frequency: 869525000, DR3, after 15987-13992= 1995ms of txdone
278 [16027]rxTimeOut --> no packet arrive in RX2 window. (duration: 40 ms)}}}
279
280 (((
281
282 )))
283
284 (((
285 **Another message:**
286 )))
287
288 {{{ [12502]***** UpLinkCounter= 0 *****
289 [12503]TX on freq 868100000 Hz at DR 0
290 [13992]txDone
291 [15022]RX on freq 868100000 Hz at DR 0
292 [15222]rxTimeOut
293 [15987]RX on freq 869525000 Hz at DR 3
294 [16185]rxDone --> We have got the downstream packet.
295 Rssi= -64
296 Receive data
297 1:0012345678}}}
298
299
300 == 5.3 If problem doesn’t solve ==
301
302 (% style="color:red" %)**If user has checked below steps and still can't solve the problem, please send us (support @ dragino.com) the sceenshots for each step to check. They include:**
303
304 * End node console to show the transmit freuqency and DR.
305 * Gateway (from gateway UI) traffic to show the packet got from end node and receive from Server.
306 * Gateway traffic (from server UI) to shows the data exchange between gateway and server.
307 * End Node traffic (from server UI) to shows end node activity in server.
308
309
310
311 = 6. Downlink Issue ~-~- Packet REJECTED, unsupported frequency =
312
313 (((
314 In LoRaWAN, the gatewat will use the frequency specify by the server to transmit a packet as downlink purpose. Each Frequency band has different downlink frequency. and the gateway has a frequency range limited to transmit downlink.
315 )))
316
317 (((
318
319 )))
320
321 (((
322 So if the LoRaWAN server is an AS923 server which ask the gateway to transmit at 923.2Mhz frequency, but the gateway is IN868 frequency band (support 865~~867Mhz to transmit). In the gateway log it will show something like below:
323 )))
324
325 {{{Sat Nov 21 08:04:17 2020 daemon.info lora_pkt_fwd[1680]: ERROR~ Packet REJECTED, unsupported frequency - 923200000 (min:865000000,max:867000000)}}}
326
327 (((
328
329 )))
330
331 (((
332 In this case, please double check the gateway frequency and the server frequency band.
333 )))
334
335
336 = 7. Decrypt a LoRaWAN Packet =
337
338 ~1. LHT65 End device configure:
339
340 (% class="box infomessage" %)
341 (((
342 **Change to ABP Mode: AT+NJM=0**
343 )))
344
345 (% class="box infomessage" %)
346 (((
347 **Change to fix frequency: AT+CHS=904900000**
348 )))
349
350 (% class="box infomessage" %)
351 (((
352 **Change to fix DR: AT+DR=0**
353 )))
354
355 [[image:image-20220526165525-16.png]]
356
357
358 2. In LG02 , configure to receive above message
359
360 [[image:image-20220526165612-17.png]]
361
362
363 In LG02 console, we can see the hex receive are:
364
365 [[image:image-20220526171112-21.png]]
366
367
368 3. Decode the info in web
369
370 [[https:~~/~~/lorawan-packet-decoder-0ta6puiniaut.runkit.sh>>url:https://lorawan-packet-decoder-0ta6puiniaut.runkit.sh/]]
371
372 Need these three fields:
373
374 LoRa packet hex format: 40c1190126800100024926272bf18bbb6341584e27e23245 (from LG02)
375
376 AT+NWKSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 11 (End node Network Session Key)
377
378 AT+APPSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 11 (End Node App Session Key)
379
380 [[https:~~/~~/lorawan-packet-decoder-0ta6puiniaut.runkit.sh/?data=40c1190126800100024926272bf18bbb6341584e27e23245&nwkskey=00000000000000000000000000000111&appskey=00000000000000000000000000000111>>url:https://lorawan-packet-decoder-0ta6puiniaut.runkit.sh/?data=40c1190126800100024926272bf18bbb6341584e27e23245&nwkskey=00000000000000000000000000000111&appskey=00000000000000000000000000000111]]
381
382 [[image:image-20220526171029-20.png]]
383
384 (((
385 The FRMPayload is the device payload.
386 )))
387
388
389 = 8. Why i see uplink 0x00 periodcally on the LHT65 v1.8 firmware =
390
391 Since firmware v1.8, LHT65 will send MAC command to request time, in the case if DR only support max 11 bytes, this MAC command will be bundled to a separate uplink payload with 0x00.
392
393
394 = 9. Why do I see a "MIC Mismatch" error message from the server? =
395
396 (((
397 1)If the user receives a "MIC Mismatch" message after registering the node on the server.
398 )))
399
400 (((
401 It is likely that the user filled in the wrong APPKEY when registering the node. Many users fill in "APPSKEY".
402 )))
403
404 * (((
405 Please note the distinction between "APPKEY" and "APPSKEY".
406 )))
407
408 (((
409 2）If the node works on the server for a period of time, the device stops working and receives a "MIC Mismatch" message.
410 )))
411
412 (((
413 The user needs a USB-TTL adapter to connect the serial port to modify the node APPKEY.
414 )))
415
416 * (((
417 If a node is registered with multiple servers, it may also cause the "mic mismatch" error.
418
419
420 )))
421
422 = 10. Why i got the payload only with "0x00" or "AA~=~="? =
423
424 * If you are using US915, AU915 and AS923 frequencies.This is normal phenomenon.
425
426 (((
427 When using the frequency mentioned above, the server sometimes adjusts the rate of the node, because the node defaults to the adaptive rate.
428 )))
429
430 (((
431 When the server adjusts your node rate to 0, the maximum payload length is 11 bytes. The server sometimes sends an ADR packet to the node,and the node will reply to the server after receiving the ADR packet, but the number of payload bytes exceeds the limit,so it will send a normal uplink packet, and an additional 00 data packet.
432 )))
433
434 * (((
435 Solution: Use the decoder to filter out this 00 packet.
436 )))
437 * (((
438 Some node decoders may not have filtering function, or you need decoders of other servers and formats. Please send an email to [[david.huang@dragino.cc>>mailto:david.huang@dragino.cc]]
439
440
441 )))
442
443 = 11. Why my Dev EUI and APP EUI is 0x000000000000, how to solve? =
444
445 (((
446 It is possible the keys is erased during upgrading of firmware. and the console output shows below after AT+CFG
447 )))
448
449 (((
450 AT+APPKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
451 )))
452
453 (((
454 AT+NWKSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
455 )))
456
457 (((
458 AT+APPSKEY=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
459 )))
460
461 (((
462 AT+APPEUI=00 00 00 00 00 00 00 00
463 )))
464
465 (((
466
467 )))
468
469 (((
470 You can get the keys from the box sticker or send mail to Dragino Support to check keys with the provided SN number.
471 )))
472
473 (((
474 You can rewrites the keys by running commands in AT Console
475 )))
476
477 (((
478 **For example：**
479 )))
480
481 (((
482 AT+APPKEY=85 41 47 20 45 58 28 14 16 82 A0 F0 80 0D DD EE
483 )))
484
485 (((
486 AT+NWKSKEY=AA CC B0 20 30 45 37 32 14 1E 14 93 E2 3B 20 11
487 )))
488
489 (((
490 AT+APPSKEY=11 23 02 20 30 20 30 60 80 20 20 30 30 20 10 10
491 )))
492
493 (((
494 AT+APPEUI=2C 45 47 E3 24 12 23 24
495 )))
496
497 (((
498 (Any combination of 16 bit codes can be used）
499 )))
500
501
502 (% class="wikigeneratedid" %)
503