Wiki source code of RS485-LN – RS485 to LoRaWAN Converter

Version 41.3 by Xiaoling on 2022/06/02 16:36

version	line-number	content
3.2	1	(% style="text-align:center" %)
18.2	2	[[image:1653266934636-343.png\|\|height="385" width="385"]]
1.1	3
	4
	5
18.2	6	RS485-LN – RS485 to LoRaWAN Converter User Manual
1.1	7
	8
3.2	9	Table of Contents:
1.1	10
	11
	12
	13
	14
3.2	15	= 1.Introduction =
1.1	16
19.2	17	== 1.1 What is RS485-LN RS485 to LoRaWAN Converter ==
1.1	18
3.2	19	(((
	20	(((
32.3	21	The Dragino RS485-LN is a (% style="color:blue" %)RS485 to LoRaWAN Converter(%%). It converts the RS485 signal into LoRaWAN wireless signal which simplify the IoT installation and reduce the installation/maintaining cost.
3.2	22	)))
2.2	23
3.2	24	(((
32.3	25	RS485-LN allows user to (% style="color:blue" %)monitor / control RS485 devices(%%) and reach extremely long ranges. It provides ultra-long range spread spectrum communication and high interference immunity whilst minimizing current consumption. It targets professional wireless sensor network applications such as irrigation systems, smart metering, smart cities, smartphone detection, building automation, and so on.
3.2	26	)))
2.2	27
3.2	28	(((
32.3	29	(% style="color:blue" %)For data uplink(%%), RS485-LN sends user-defined commands to RS485 devices and gets the return from the RS485 devices. RS485-LN will process these returns according to user-define rules to get the final payload and upload to LoRaWAN server.
3.2	30	)))
2.2	31
3.2	32	(((
32.3	33	(% style="color:blue" %)For data downlink(%%), RS485-LN runs in LoRaWAN Class C. When there downlink commands from LoRaWAN server, RS485-LN will forward the commands from LoRaWAN server to RS485 devices.
32.2	34
32.3	35	(% style="color:blue" %)Demo Dashboard for RS485-LN(%%) connect to two energy meters: [[https:~~/~~/app.datacake.de/dashboard/d/58844a26-378d-4c5a-aaf5-b5b5b153447a>>url:https://app.datacake.de/dashboard/d/58844a26-378d-4c5a-aaf5-b5b5b153447a]]
3.2	36	)))
	37	)))
2.2	38
19.2	39	[[image:1653267211009-519.png\|\|height="419" width="724"]]
2.2	40
32.4	41
3.2	42	== 1.2 Specifications ==
2.2	43
32.6	44
2.2	45	Hardware System:
	46
	47	* STM32L072CZT6 MCU
22.4	48	* SX1276/78 Wireless Chip
2.2	49	* Power Consumption (exclude RS485 device):
19.3	50	** Idle: 32mA@12v
	51	** 20dB Transmit: 65mA@12v
2.2	52
	53	Interface for Model:
	54
19.3	55	* RS485
22.4	56	* Power Input 7~~ 24V DC.
2.2	57
	58	LoRa Spec:
	59
	60	* Frequency Range:
	61	** Band 1 (HF): 862 ~~ 1020 Mhz
	62	** Band 2 (LF): 410 ~~ 528 Mhz
	63	* 168 dB maximum link budget.
	64	* +20 dBm - 100 mW constant RF output vs.
19.3	65	* +14 dBm high efficiency PA.
2.2	66	* Programmable bit rate up to 300 kbps.
	67	* High sensitivity: down to -148 dBm.
	68	* Bullet-proof front end: IIP3 = -12.5 dBm.
	69	* Excellent blocking immunity.
19.3	70	* Low RX current of 10.3 mA, 200 nA register retention.
2.2	71	* Fully integrated synthesizer with a resolution of 61 Hz.
19.3	72	* FSK, GFSK, MSK, GMSK, LoRaTM and OOK modulation.
2.2	73	* Built-in bit synchronizer for clock recovery.
	74	* Preamble detection.
	75	* 127 dB Dynamic Range RSSI.
19.3	76	* Automatic RF Sense and CAD with ultra-fast AFC.
	77	* Packet engine up to 256 bytes with CRC.
2.2	78
41.2	79
3.3	80	== 1.3 Features ==
2.2	81
19.4	82	* LoRaWAN Class A & Class C protocol (default Class C)
2.2	83	* Frequency Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915/IN865/RU864
	84	* AT Commands to change parameters
19.4	85	* Remote configure parameters via LoRa Downlink
2.2	86	* Firmware upgradable via program port
	87	* Support multiply RS485 devices by flexible rules
	88	* Support Modbus protocol
19.4	89	* Support Interrupt uplink (Since hardware version v1.2)
2.2	90
41.3	91
3.3	92	== 1.4 Applications ==
2.2	93
	94	* Smart Buildings & Home Automation
	95	* Logistics and Supply Chain Management
	96	* Smart Metering
	97	* Smart Agriculture
	98	* Smart Cities
	99	* Smart Factory
	100
6.2	101	== 1.5 Firmware Change log ==
2.2	102
19.4	103	[[RS485-LN Image files – Download link and Change log>>url:http://www.dragino.com/downloads/index.php?dir=RS485-LN/]]
2.2	104
32.10	105
4.2	106	== 1.6 Hardware Change log ==
2.2	107
4.2	108	(((
	109	(((
19.4	110	v1.2: Add External Interrupt Pin.
2.2	111
19.4	112	v1.0: Release
32.10	113
	114
4.2	115	)))
	116	)))
2.2	117
20.2	118	= 2. Power ON Device =
2.2	119
6.2	120	(((
20.2	121	The RS485-LN can be powered by 7 ~~ 24V DC power source. Connection as below
2.2	122
20.2	123	* Power Source VIN to RS485-LN VIN+
	124	* Power Source GND to RS485-LN VIN-
2.2	125
20.3	126	(((
20.2	127	Once there is power, the RS485-LN will be on.
20.3	128	)))
2.2	129
20.2	130	[[image:1653268091319-405.png]]
32.11	131
	132
20.2	133	)))
2.2	134
6.2	135	= 3. Operation Mode =
2.2	136
6.2	137	== 3.1 How it works? ==
2.2	138
7.2	139	(((
21.2	140	The RS485-LN is configured as LoRaWAN OTAA Class C mode by default. It has OTAA keys to join network. To connect a local LoRaWAN network, user just need to input the OTAA keys in the network server and power on the RS485-LN. It will auto join the network via OTAA.
32.12	141
	142
7.2	143	)))
2.2	144
7.2	145	== 3.2 Example to join LoRaWAN network ==
2.2	146
6.2	147	Here shows an example for how to join the TTN V3 Network. Below is the network structure, we use [[LG308>>url:http://www.dragino.com/products/lora-lorawan-gateway/item/140-lg308.html]] as LoRaWAN gateway here.
2.2	148
21.2	149	[[image:1653268155545-638.png\|\|height="334" width="724"]]
2.2	150
32.13	151
15.3	152	(((
32.13	153	(((
22.2	154	The RS485-LN in this example connected to two RS485 devices for demonstration, user can connect to other RS485 devices via the same method. The connection is as below:
32.13	155	)))
2.2	156
32.13	157	(((
22.2	158	485A+ and 485B- of the sensor are connected to RS485A and RA485B of RS485-LN respectively.
32.13	159	)))
22.2	160
	161	[[image:1653268227651-549.png\|\|height="592" width="720"]]
	162
15.3	163	(((
22.2	164	The LG308 is already set to connect to [[TTN V3 network >>path:eu1.cloud.thethings.network/]]. So what we need to now is only configure the TTN V3:
15.3	165	)))
2.2	166
15.3	167	(((
22.2	168	Step 1: Create a device in TTN V3 with the OTAA keys from RS485-LN.
15.3	169	)))
2.2	170
15.3	171	(((
22.2	172	Each RS485-LN is shipped with a sticker with unique device EUI:
15.3	173	)))
22.2	174	)))
2.2	175
15.2	176	[[image:1652953462722-299.png]]
2.2	177
15.3	178	(((
22.3	179	(((
2.2	180	User can enter this key in their LoRaWAN Server portal. Below is TTN V3 screen shot:
15.3	181	)))
2.2	182
15.3	183	(((
2.2	184	Add APP EUI in the application.
15.3	185	)))
22.3	186	)))
2.2	187
15.2	188	[[image:image-20220519174512-1.png]]
2.2	189
22.3	190	[[image:image-20220519174512-2.png\|\|height="323" width="720"]]
2.2	191
15.2	192	[[image:image-20220519174512-3.png\|\|height="556" width="724"]]
2.2	193
15.2	194	[[image:image-20220519174512-4.png]]
2.2	195
	196	You can also choose to create the device manually.
	197
15.2	198	[[image:1652953542269-423.png\|\|height="710" width="723"]]
2.2	199
	200	Add APP KEY and DEV EUI
	201
15.2	202	[[image:1652953553383-907.png\|\|height="514" width="724"]]
2.2	203
	204
15.2	205	(((
22.4	206	Step 2: Power on RS485-LN and it will auto join to the TTN V3 network. After join success, it will start to upload message to TTN V3 and user can see in the panel.
15.2	207	)))
2.2	208
15.2	209	[[image:1652953568895-172.png\|\|height="232" width="724"]]
2.2	210
32.14	211
15.5	212	== 3.3 Configure Commands to read data ==
2.2	213
15.5	214	(((
22.4	215	(((
	216	There are plenty of RS485 devices in the market and each device has different command to read the valid data. To support these devices in flexible, RS485-LN supports flexible command set. User can use [[AT Commands>>path:#AT_COMMAND]] or LoRaWAN Downlink Command to configure what commands RS485-LN should send for each sampling and how to handle the return from RS485 devices.
15.5	217	)))
2.2	218
22.4	219	(((
	220	(% style="color:red" %)Note: below description and commands are for firmware version >v1.1, if you have firmware version v1.0. Please check the [[user manual v1.0>>url:http://www.dragino.com/downloads/index.php?dir=RS485-LN/&file=RS485-LN_UserManual_v1.0.1.pdf]] or upgrade the firmware to v1.1
32.15	221
	222
22.4	223	)))
	224	)))
	225
15.5	226	=== 3.3.1 onfigure UART settings for RS485 or TTL communication ===
2.2	227
22.6	228	To use RS485-LN to read data from RS485 sensors, connect the RS485-LN A/B traces to the sensors. And user need to make sure RS485-LN use the match UART setting to access the sensors. The related commands for UART settings are:
2.2	229
32.16	230	(% border="1" style="background-color:#ffffcc; color:green; width:782px" %)
	231	\|(% style="width:128px" %)(((
15.5	232	AT Commands
32.16	233	)))\|(% style="width:305px" %)(((
15.5	234	Description
32.16	235	)))\|(% style="width:346px" %)(((
15.5	236	Example
	237	)))
32.16	238	\|(% style="width:128px" %)(((
15.5	239	AT+BAUDR
32.16	240	)))\|(% style="width:305px" %)(((
15.5	241	Set the baud rate (for RS485 connection). Default Value is: 9600.
32.16	242	)))\|(% style="width:346px" %)(((
15.5	243	(((
2.2	244	AT+BAUDR=9600
15.5	245	)))
2.2	246
15.5	247	(((
2.2	248	Options: (1200,2400,4800,14400,19200,115200)
	249	)))
15.5	250	)))
32.16	251	\|(% style="width:128px" %)(((
15.5	252	AT+PARITY
32.16	253	)))\|(% style="width:305px" %)(((
2.2	254	Set UART parity (for RS485 connection)
32.16	255	)))\|(% style="width:346px" %)(((
15.5	256	(((
2.2	257	AT+PARITY=0
15.5	258	)))
2.2	259
15.5	260	(((
2.2	261	Option: 0: no parity, 1: odd parity, 2: even parity
	262	)))
15.5	263	)))
32.16	264	\|(% style="width:128px" %)(((
15.5	265	AT+STOPBIT
32.16	266	)))\|(% style="width:305px" %)(((
15.5	267	(((
2.2	268	Set serial stopbit (for RS485 connection)
15.5	269	)))
2.2	270
15.5	271	(((
22.6	272
15.5	273	)))
32.16	274	)))\|(% style="width:346px" %)(((
15.5	275	(((
2.2	276	AT+STOPBIT=0 for 1bit
15.5	277	)))
2.2	278
15.5	279	(((
2.2	280	AT+STOPBIT=1 for 1.5 bit
15.5	281	)))
2.2	282
15.5	283	(((
2.2	284	AT+STOPBIT=2 for 2 bits
	285	)))
15.5	286	)))
2.2	287
15.6	288	=== 3.3.2 Configure sensors ===
2.2	289
15.6	290	(((
	291	(((
22.7	292	Some sensors might need to configure before normal operation. User can configure such sensor via PC and RS485 adapter or through RS485-LN AT Commands (% style="color:#4f81bd" %)AT+CFGDEV(%%). Each (% style="color:#4f81bd" %)AT+CFGDEV (%%)equals to send a RS485 command to sensors. This command will only run when user input it and won’t run during each sampling.
15.6	293	)))
22.7	294	)))
2.2	295
15.6	296	(% border="1" style="background-color:#ffffcc; color:green; width:806px" %)
	297	\|AT Commands\|(% style="width:418px" %)Description\|(% style="width:256px" %)Example
	298	\|AT+CFGDEV\|(% style="width:418px" %)(((
2.2	299	This command is used to configure the RS485/TTL devices; they won’t be used during sampling.
	300
15.6	301	AT+CFGDEV=xx xx xx xx xx xx xx xx xx xx xx xx,
2.2	302
15.6	303	mm: 0: no CRC, 1: add CRC-16/MODBUS in the end of this command
	304	)))\|(% style="width:256px" %)AT+CFGDEV=xx xx xx xx xx xx xx xx xx xx xx xx,m
2.2	305
15.6	306	=== 3.3.3 Configure read commands for each sampling ===
2.2	307
15.6	308	(((
35.2	309	During each sampling, we need confirm what commands we need to send to the RS485 sensors to read data. After the RS485 sensors send back the value, it normally include some bytes and we only need a few from them for a shorten payload.
2.2	310
	311	To save the LoRaWAN network bandwidth, we might need to read data from different sensors and combine their valid value into a short payload.
	312
	313	This section describes how to achieve above goals.
	314
35.2	315	During each sampling, the RS485-LN can support 15 commands to read sensors. And combine the return to one or several uplink payloads.
2.2	316
	317
35.2	318	Each RS485 commands include two parts:
2.2	319
35.2	320	~1. What commands RS485-LN will send to the RS485 sensors. There are total 15 commands from AT+COMMAD1, ATCOMMAND2,…, to AT+COMMANDF. All commands are of same grammar.
2.2	321
35.2	322	2. How to get wanted value the from RS485 sensors returns from by 1). There are total 15 AT Commands to handle the return, commands are AT+DATACUT1,AT+DATACUT2,…, AT+DATACUTF corresponding to the commands from 1). All commands are of same grammar.
2.2	323
35.4	324	3. Some RS485 device might has longer delay on reply, so user can use AT+CMDDL to set the timeout for getting reply after the RS485 command is sent. For example AT+CMDDL1=1000 to send the open time to 1000ms
2.2	325
	326
	327	After we got the valid value from each RS485 commands, we need to combine them together with the command AT+DATAUP.
	328
	329
	330	Below are examples for the how above AT Commands works.
	331
	332
35.2	333	AT+COMMANDx : This command will be sent to RS485 devices during each sampling, Max command length is 14 bytes. The grammar is:
	334
	335	(% border="1" style="background-color:#4bacc6; color:white; width:499px" %)
	336	\|(% style="width:496px" %)(((
2.2	337	AT+COMMANDx=xx xx xx xx xx xx xx xx xx xx xx xx,m
	338
	339	xx xx xx xx xx xx xx xx xx xx xx xx: The RS485 command to be sent
	340
	341	m: 0: no CRC, 1: add CRC-16/MODBUS in the end of this command
	342	)))
	343
	344	For example, if we have a RS485 sensor. The command to get sensor value is: 01 03 0B B8 00 02 46 0A. Where 01 03 0B B8 00 02 is the Modbus command to read the register 0B B8 where stored the sensor value. The 46 0A is the CRC-16/MODBUS which calculate manually.
	345
35.2	346	In the RS485-LN, we should use this command AT+COMMAND1=01 03 0B B8 00 02,1 for the same.
2.2	347
	348
	349	AT+DATACUTx : This command defines how to handle the return from AT+COMMANDx, max return length is 45 bytes.
	350
35.2	351	(% border="1" style="background-color:#4bacc6; color:white; width:725px" %)
	352	\|(% style="width:722px" %)(((
2.2	353	AT+DATACUTx=a,b,c
	354
	355	* a: length for the return of AT+COMMAND
	356	* b:1: grab valid value by byte, max 6 bytes. 2: grab valid value by bytes section, max 3 sections.
35.5	357	* c: define the position for valid value.
2.2	358	)))
	359
35.2	360	Examples:
	361
2.2	362	* Grab bytes:
	363
35.2	364	[[image:image-20220602153621-1.png]]
2.2	365
35.2	366
2.2	367	* Grab a section.
	368
35.2	369	[[image:image-20220602153621-2.png]]
2.2	370
35.2	371
2.2	372	* Grab different sections.
	373
35.2	374	[[image:image-20220602153621-3.png]]
35.3	375
	376
35.2	377	)))
2.2	378
29.2	379	=== 3.3.4 Compose the uplink payload ===
2.2	380
29.2	381	(((
2.2	382	Through AT+COMMANDx and AT+DATACUTx we got valid value from each RS485 commands, Assume these valid value are RETURN1, RETURN2, .., to RETURNx. The next step is how to compose the LoRa Uplink Payload by these RETURNs. The command is AT+DATAUP.
35.5	383
	384
29.2	385	)))
2.2	386
29.2	387	(((
35.5	388	(% style="color:#037691" %)Examples: AT+DATAUP=0
	389
	390
29.2	391	)))
2.2	392
29.2	393	(((
	394	Compose the uplink payload with value returns in sequence and send with (% style="color:red" %)A SIGNLE UPLINK.
	395	)))
2.2	396
29.2	397	(((
2.2	398	Final Payload is
29.2	399	)))
2.2	400
29.2	401	(((
	402	(% style="color:#4f81bd" %)Battery Info+PAYVER + VALID Value from RETURN1 + Valid Value from RETURN2 + … + RETURNx
	403	)))
2.2	404
29.2	405	(((
2.2	406	Where PAYVER is defined by AT+PAYVER, below is an example screen shot.
29.2	407	)))
2.2	408
29.3	409	[[image:1653269759169-150.png\|\|height="513" width="716"]]
2.2	410
35.5	411
35.6	412	(% style="color:#037691" %)Examples: AT+DATAUP=1
2.2	413
35.5	414
30.2	415	Compose the uplink payload with value returns in sequence and send with (% style="color:red" %)Multiply UPLINKs.
2.2	416
	417	Final Payload is
	418
30.2	419	(% style="color:#4f81bd" %)Battery Info+PAYVER + PAYLOAD COUNT + PAYLOAD# + DATA
2.2	420
36.2	421	1. PAYVER: Defined by AT+PAYVER
	422	1. PAYLOAD COUNT: Total how many uplinks of this sampling.
	423	1. PAYLOAD#: Number of this uplink. (from 0,1,2,3…,to PAYLOAD COUNT)
	424	1. DATA: Valid value: max 8 bytes for each uplink so each uplink <= 11 bytes. For the last uplink, DATA will might less than 8 bytes
2.2	425
36.2	426	[[image:image-20220602155039-4.png]]
2.2	427
	428
36.2	429	So totally there will be 3 uplinks for this sampling, each uplink include 8 bytes DATA
2.2	430
36.2	431	DATA1=RETURN1 Valid Value + the first two of Valid value of RETURN10= 20 20 0a 33 90 41 02 aa
2.2	432
36.2	433	DATA2=3^^rd^^ ~~ 10^^th^^ byte of Valid value of RETURN10= 05 81 0a 20 20 20 20 2d
2.2	434
36.2	435	DATA3=the rest of Valid value of RETURN10= 30
2.2	436
36.2	437
	438	(% style="color:red" %)Notice: In firmware v1.3, the Max bytes has been changed according to the max bytes in different Frequency Bands for lowest SF. As below:
	439
	440	~* For AU915/AS923 bands, if UplinkDwell time=0, max 51 bytes for each uplink.
	441
	442	* For AU915/AS923 bands, if UplinkDwell time=0, max 11 bytes for each uplink.
	443
	444	* For US915 band, max 11 bytes for each uplink.
	445
	446	~* For all other bands: max 51 bytes for each uplink.
	447
	448
2.2	449	Below are the uplink payloads:
	450
37.2	451	[[image:1654157178836-407.png]]
2.2	452
	453
31.3	454	=== 3.3.5 Uplink on demand ===
2.2	455
37.4	456	Except uplink periodically, RS485-LN is able to uplink on demand. The server send downlink command to RS485-LN and RS485 will uplink data base on the command.
2.2	457
	458	Downlink control command:
	459
37.4	460	0x08 command: Poll an uplink with current command set in RS485-LN.
2.2	461
37.4	462	0xA8 command: Send a command to RS485-LN and uplink the output from sensors.
2.2	463
	464
	465
38.2	466	=== 3.3.6 Uplink on Interrupt ===
2.2	467
38.2	468	RS485-LN support external Interrupt uplink since hardware v1.2 release.
2.2	469
38.2	470	[[image:1654157342174-798.png]]
2.2	471
38.2	472	Connect the Interrupt pin to RS485-LN INT port and connect the GND pin to V- port. When there is a high voltage (Max 24v) on INT pin. Device will send an uplink packet.
2.2	473
	474
38.4	475	== 3.4 Uplink Payload ==
2.2	476
38.4	477	(% border="1" style="background-color:#4bacc6; color:white; width:734px" %)
	478	\|Size(bytes)\|(% style="width:120px" %)2\|(% style="width:116px" %)1\|(% style="width:386px" %)Length depends on the return from the commands
	479	\|Value\|(% style="width:120px" %)(((
2.2	480	Battery(mV)
	481
	482	&
	483
	484	Interrupt _Flag
38.4	485	)))\|(% style="width:116px" %)(((
2.2	486	PAYLOAD_VER
	487
	488
38.4	489	)))\|(% style="width:386px" %)If the valid payload is too long and exceed the maximum support payload length in server, server will show payload not provided in the LoRaWAN server.
2.2	490
	491	Below is the decoder for the first 3 bytes. The rest bytes are dynamic depends on different RS485 sensors.
	492
	493
38.4	494	== 3.5 Configure RS485-BL via AT or Downlink ==
2.2	495
38.4	496	User can configure RS485-LN via AT Commands or LoRaWAN Downlink Commands
2.2	497
38.4	498	There are two kinds of Commands:
2.2	499
38.4	500	* (% style="color:#4f81bd" %)Common Commands(%%): They should be available for each sensor, such as: change uplink interval, reset device. For firmware v1.3, user can find what common commands it supports: [[End Device AT Commands and Downlink Command>>doc:Main.End Device AT Commands and Downlink Command.WebHome]]
2.2	501
38.4	502	* (% style="color:#4f81bd" %)Sensor Related Commands(%%): These commands are special designed for RS485-LN. User can see these commands below:
2.2	503
38.4	504	=== 3.5.1 Common Commands ===
2.2	505
38.4	506	They should be available for each of Dragino Sensors, such as: change uplink interval, reset device. For firmware v1.3, user can find what common commands it supports: [[End Device AT Commands and Downlink Command>>doc:Main.End Device AT Commands and Downlink Command.WebHome]]
2.2	507
	508
41.1	509	=== 3.5.2 Sensor related commands ===
2.2	510
41.1	511	Response feature is added to the server's downlink, a special package with a FPort of 200 will be uploaded immediately after receiving the data sent by the server.
2.2	512
41.1	513	[[image:image-20220602163333-5.png\|\|height="263" width="1160"]]
2.2	514
41.1	515	The first byte of this package represents whether the configuration is successful, 00 represents failure, 01 represents success. Except for the first byte, the other is the previous downlink. (All commands except A8 type commands are applicable)
2.2	516
	517
41.1	518	3.5.3 Sensor related commands
2.2	519
41.1	520	==== ====
2.2	521
41.1	522	==== ====

Wiki source code of RS485-LN – RS485 to LoRaWAN Converter

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