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

Version 41.2 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
3.3	91	== 1.4 Applications ==
2.2	92
	93	* Smart Buildings & Home Automation
	94	* Logistics and Supply Chain Management
	95	* Smart Metering
	96	* Smart Agriculture
	97	* Smart Cities
	98	* Smart Factory
	99
6.2	100	== 1.5 Firmware Change log ==
2.2	101
19.4	102	[[RS485-LN Image files – Download link and Change log>>url:http://www.dragino.com/downloads/index.php?dir=RS485-LN/]]
2.2	103
32.10	104
4.2	105	== 1.6 Hardware Change log ==
2.2	106
4.2	107	(((
	108	(((
19.4	109	v1.2: Add External Interrupt Pin.
2.2	110
19.4	111	v1.0: Release
32.10	112
	113
4.2	114	)))
	115	)))
2.2	116
20.2	117	= 2. Power ON Device =
2.2	118
6.2	119	(((
20.2	120	The RS485-LN can be powered by 7 ~~ 24V DC power source. Connection as below
2.2	121
20.2	122	* Power Source VIN to RS485-LN VIN+
	123	* Power Source GND to RS485-LN VIN-
2.2	124
20.3	125	(((
20.2	126	Once there is power, the RS485-LN will be on.
20.3	127	)))
2.2	128
20.2	129	[[image:1653268091319-405.png]]
32.11	130
	131
20.2	132	)))
2.2	133
6.2	134	= 3. Operation Mode =
2.2	135
6.2	136	== 3.1 How it works? ==
2.2	137
7.2	138	(((
21.2	139	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	140
	141
7.2	142	)))
2.2	143
7.2	144	== 3.2 Example to join LoRaWAN network ==
2.2	145
6.2	146	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	147
21.2	148	[[image:1653268155545-638.png\|\|height="334" width="724"]]
2.2	149
32.13	150
15.3	151	(((
32.13	152	(((
22.2	153	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	154	)))
2.2	155
32.13	156	(((
22.2	157	485A+ and 485B- of the sensor are connected to RS485A and RA485B of RS485-LN respectively.
32.13	158	)))
22.2	159
	160	[[image:1653268227651-549.png\|\|height="592" width="720"]]
	161
15.3	162	(((
22.2	163	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	164	)))
2.2	165
15.3	166	(((
22.2	167	Step 1: Create a device in TTN V3 with the OTAA keys from RS485-LN.
15.3	168	)))
2.2	169
15.3	170	(((
22.2	171	Each RS485-LN is shipped with a sticker with unique device EUI:
15.3	172	)))
22.2	173	)))
2.2	174
15.2	175	[[image:1652953462722-299.png]]
2.2	176
15.3	177	(((
22.3	178	(((
2.2	179	User can enter this key in their LoRaWAN Server portal. Below is TTN V3 screen shot:
15.3	180	)))
2.2	181
15.3	182	(((
2.2	183	Add APP EUI in the application.
15.3	184	)))
22.3	185	)))
2.2	186
15.2	187	[[image:image-20220519174512-1.png]]
2.2	188
22.3	189	[[image:image-20220519174512-2.png\|\|height="323" width="720"]]
2.2	190
15.2	191	[[image:image-20220519174512-3.png\|\|height="556" width="724"]]
2.2	192
15.2	193	[[image:image-20220519174512-4.png]]
2.2	194
	195	You can also choose to create the device manually.
	196
15.2	197	[[image:1652953542269-423.png\|\|height="710" width="723"]]
2.2	198
	199	Add APP KEY and DEV EUI
	200
15.2	201	[[image:1652953553383-907.png\|\|height="514" width="724"]]
2.2	202
	203
15.2	204	(((
22.4	205	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	206	)))
2.2	207
15.2	208	[[image:1652953568895-172.png\|\|height="232" width="724"]]
2.2	209
32.14	210
15.5	211	== 3.3 Configure Commands to read data ==
2.2	212
15.5	213	(((
22.4	214	(((
	215	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	216	)))
2.2	217
22.4	218	(((
	219	(% 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	220
	221
22.4	222	)))
	223	)))
	224
15.5	225	=== 3.3.1 onfigure UART settings for RS485 or TTL communication ===
2.2	226
22.6	227	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	228
32.16	229	(% border="1" style="background-color:#ffffcc; color:green; width:782px" %)
	230	\|(% style="width:128px" %)(((
15.5	231	AT Commands
32.16	232	)))\|(% style="width:305px" %)(((
15.5	233	Description
32.16	234	)))\|(% style="width:346px" %)(((
15.5	235	Example
	236	)))
32.16	237	\|(% style="width:128px" %)(((
15.5	238	AT+BAUDR
32.16	239	)))\|(% style="width:305px" %)(((
15.5	240	Set the baud rate (for RS485 connection). Default Value is: 9600.
32.16	241	)))\|(% style="width:346px" %)(((
15.5	242	(((
2.2	243	AT+BAUDR=9600
15.5	244	)))
2.2	245
15.5	246	(((
2.2	247	Options: (1200,2400,4800,14400,19200,115200)
	248	)))
15.5	249	)))
32.16	250	\|(% style="width:128px" %)(((
15.5	251	AT+PARITY
32.16	252	)))\|(% style="width:305px" %)(((
2.2	253	Set UART parity (for RS485 connection)
32.16	254	)))\|(% style="width:346px" %)(((
15.5	255	(((
2.2	256	AT+PARITY=0
15.5	257	)))
2.2	258
15.5	259	(((
2.2	260	Option: 0: no parity, 1: odd parity, 2: even parity
	261	)))
15.5	262	)))
32.16	263	\|(% style="width:128px" %)(((
15.5	264	AT+STOPBIT
32.16	265	)))\|(% style="width:305px" %)(((
15.5	266	(((
2.2	267	Set serial stopbit (for RS485 connection)
15.5	268	)))
2.2	269
15.5	270	(((
22.6	271
15.5	272	)))
32.16	273	)))\|(% style="width:346px" %)(((
15.5	274	(((
2.2	275	AT+STOPBIT=0 for 1bit
15.5	276	)))
2.2	277
15.5	278	(((
2.2	279	AT+STOPBIT=1 for 1.5 bit
15.5	280	)))
2.2	281
15.5	282	(((
2.2	283	AT+STOPBIT=2 for 2 bits
	284	)))
15.5	285	)))
2.2	286
15.6	287	=== 3.3.2 Configure sensors ===
2.2	288
15.6	289	(((
	290	(((
22.7	291	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	292	)))
22.7	293	)))
2.2	294
15.6	295	(% border="1" style="background-color:#ffffcc; color:green; width:806px" %)
	296	\|AT Commands\|(% style="width:418px" %)Description\|(% style="width:256px" %)Example
	297	\|AT+CFGDEV\|(% style="width:418px" %)(((
2.2	298	This command is used to configure the RS485/TTL devices; they won’t be used during sampling.
	299
15.6	300	AT+CFGDEV=xx xx xx xx xx xx xx xx xx xx xx xx,
2.2	301
15.6	302	mm: 0: no CRC, 1: add CRC-16/MODBUS in the end of this command
	303	)))\|(% style="width:256px" %)AT+CFGDEV=xx xx xx xx xx xx xx xx xx xx xx xx,m
2.2	304
15.6	305	=== 3.3.3 Configure read commands for each sampling ===
2.2	306
15.6	307	(((
35.2	308	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	309
	310	To save the LoRaWAN network bandwidth, we might need to read data from different sensors and combine their valid value into a short payload.
	311
	312	This section describes how to achieve above goals.
	313
35.2	314	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	315
	316
35.2	317	Each RS485 commands include two parts:
2.2	318
35.2	319	~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	320
35.2	321	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	322
35.4	323	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	324
	325
	326	After we got the valid value from each RS485 commands, we need to combine them together with the command AT+DATAUP.
	327
	328
	329	Below are examples for the how above AT Commands works.
	330
	331
35.2	332	AT+COMMANDx : This command will be sent to RS485 devices during each sampling, Max command length is 14 bytes. The grammar is:
	333
	334	(% border="1" style="background-color:#4bacc6; color:white; width:499px" %)
	335	\|(% style="width:496px" %)(((
2.2	336	AT+COMMANDx=xx xx xx xx xx xx xx xx xx xx xx xx,m
	337
	338	xx xx xx xx xx xx xx xx xx xx xx xx: The RS485 command to be sent
	339
	340	m: 0: no CRC, 1: add CRC-16/MODBUS in the end of this command
	341	)))
	342
	343	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.
	344
35.2	345	In the RS485-LN, we should use this command AT+COMMAND1=01 03 0B B8 00 02,1 for the same.
2.2	346
	347
	348	AT+DATACUTx : This command defines how to handle the return from AT+COMMANDx, max return length is 45 bytes.
	349
35.2	350	(% border="1" style="background-color:#4bacc6; color:white; width:725px" %)
	351	\|(% style="width:722px" %)(((
2.2	352	AT+DATACUTx=a,b,c
	353
	354	* a: length for the return of AT+COMMAND
	355	* b:1: grab valid value by byte, max 6 bytes. 2: grab valid value by bytes section, max 3 sections.
35.5	356	* c: define the position for valid value.
2.2	357	)))
	358
35.2	359	Examples:
	360
2.2	361	* Grab bytes:
	362
35.2	363	[[image:image-20220602153621-1.png]]
2.2	364
35.2	365
2.2	366	* Grab a section.
	367
35.2	368	[[image:image-20220602153621-2.png]]
2.2	369
35.2	370
2.2	371	* Grab different sections.
	372
35.2	373	[[image:image-20220602153621-3.png]]
35.3	374
	375
35.2	376	)))
2.2	377
29.2	378	=== 3.3.4 Compose the uplink payload ===
2.2	379
29.2	380	(((
2.2	381	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	382
	383
29.2	384	)))
2.2	385
29.2	386	(((
35.5	387	(% style="color:#037691" %)Examples: AT+DATAUP=0
	388
	389
29.2	390	)))
2.2	391
29.2	392	(((
	393	Compose the uplink payload with value returns in sequence and send with (% style="color:red" %)A SIGNLE UPLINK.
	394	)))
2.2	395
29.2	396	(((
2.2	397	Final Payload is
29.2	398	)))
2.2	399
29.2	400	(((
	401	(% style="color:#4f81bd" %)Battery Info+PAYVER + VALID Value from RETURN1 + Valid Value from RETURN2 + … + RETURNx
	402	)))
2.2	403
29.2	404	(((
2.2	405	Where PAYVER is defined by AT+PAYVER, below is an example screen shot.
29.2	406	)))
2.2	407
29.3	408	[[image:1653269759169-150.png\|\|height="513" width="716"]]
2.2	409
35.5	410
35.6	411	(% style="color:#037691" %)Examples: AT+DATAUP=1
2.2	412
35.5	413
30.2	414	Compose the uplink payload with value returns in sequence and send with (% style="color:red" %)Multiply UPLINKs.
2.2	415
	416	Final Payload is
	417
30.2	418	(% style="color:#4f81bd" %)Battery Info+PAYVER + PAYLOAD COUNT + PAYLOAD# + DATA
2.2	419
36.2	420	1. PAYVER: Defined by AT+PAYVER
	421	1. PAYLOAD COUNT: Total how many uplinks of this sampling.
	422	1. PAYLOAD#: Number of this uplink. (from 0,1,2,3…,to PAYLOAD COUNT)
	423	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	424
36.2	425	[[image:image-20220602155039-4.png]]
2.2	426
	427
36.2	428	So totally there will be 3 uplinks for this sampling, each uplink include 8 bytes DATA
2.2	429
36.2	430	DATA1=RETURN1 Valid Value + the first two of Valid value of RETURN10= 20 20 0a 33 90 41 02 aa
2.2	431
36.2	432	DATA2=3^^rd^^ ~~ 10^^th^^ byte of Valid value of RETURN10= 05 81 0a 20 20 20 20 2d
2.2	433
36.2	434	DATA3=the rest of Valid value of RETURN10= 30
2.2	435
36.2	436
	437	(% 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:
	438
	439	~* For AU915/AS923 bands, if UplinkDwell time=0, max 51 bytes for each uplink.
	440
	441	* For AU915/AS923 bands, if UplinkDwell time=0, max 11 bytes for each uplink.
	442
	443	* For US915 band, max 11 bytes for each uplink.
	444
	445	~* For all other bands: max 51 bytes for each uplink.
	446
	447
2.2	448	Below are the uplink payloads:
	449
37.2	450	[[image:1654157178836-407.png]]
2.2	451
	452
31.3	453	=== 3.3.5 Uplink on demand ===
2.2	454
37.4	455	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	456
	457	Downlink control command:
	458
37.4	459	0x08 command: Poll an uplink with current command set in RS485-LN.
2.2	460
37.4	461	0xA8 command: Send a command to RS485-LN and uplink the output from sensors.
2.2	462
	463
	464
38.2	465	=== 3.3.6 Uplink on Interrupt ===
2.2	466
38.2	467	RS485-LN support external Interrupt uplink since hardware v1.2 release.
2.2	468
38.2	469	[[image:1654157342174-798.png]]
2.2	470
38.2	471	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	472
	473
38.4	474	== 3.4 Uplink Payload ==
2.2	475
38.4	476	(% border="1" style="background-color:#4bacc6; color:white; width:734px" %)
	477	\|Size(bytes)\|(% style="width:120px" %)2\|(% style="width:116px" %)1\|(% style="width:386px" %)Length depends on the return from the commands
	478	\|Value\|(% style="width:120px" %)(((
2.2	479	Battery(mV)
	480
	481	&
	482
	483	Interrupt _Flag
38.4	484	)))\|(% style="width:116px" %)(((
2.2	485	PAYLOAD_VER
	486
	487
38.4	488	)))\|(% 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	489
	490	Below is the decoder for the first 3 bytes. The rest bytes are dynamic depends on different RS485 sensors.
	491
	492
38.4	493	== 3.5 Configure RS485-BL via AT or Downlink ==
2.2	494
38.4	495	User can configure RS485-LN via AT Commands or LoRaWAN Downlink Commands
2.2	496
38.4	497	There are two kinds of Commands:
2.2	498
38.4	499	* (% 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	500
38.4	501	* (% style="color:#4f81bd" %)Sensor Related Commands(%%): These commands are special designed for RS485-LN. User can see these commands below:
2.2	502
38.4	503	=== 3.5.1 Common Commands ===
2.2	504
38.4	505	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	506
	507
41.1	508	=== 3.5.2 Sensor related commands ===
2.2	509
41.1	510	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	511
41.1	512	[[image:image-20220602163333-5.png\|\|height="263" width="1160"]]
2.2	513
41.1	514	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	515
	516
41.1	517	3.5.3 Sensor related commands
2.2	518
41.1	519	==== ====
2.2	520
41.1	521	==== ====

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

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