Elecom LSN50v2-S31 User manual

LSN50v2-S31-S31B LoRaWAN Temperature &
Humidity Sensor User Manual
last modified by Xiaoling
on 2023/04/28 10:19

User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
Table of Contents
1. Introduction ........................................................................................................................................................................ 4
1.1 What is LSN50V2-S31 LoRaWAN Temperature & Humidity Sensor .................................................................... 4
1.2 Specifications ................................................................................................................................................................ 5
1.3 Features ........................................................................................................................................................................ 6
1.4 Applications ................................................................................................................................................................... 6
1.5 Pin Definitions and Switch .......................................................................................................................................... 6
1.5.1 Pin Definition ........................................................................................................................................................... 7
1.5.2 Jumper JP2 ............................................................................................................................................................. 7
1.5.3 BOOT MODE / SW1 .............................................................................................................................................. 7
1.5.4 Reset Button ............................................................................................................................................................ 7
1.5.5 LED ........................................................................................................................................................................... 7
1.5.6 Probe Dimension .................................................................................................................................................... 8
1.6 Hardware Variant ........................................................................................................................................................ 8
2. How to use LSN50v2-S31? ............................................................................................................................................ 8
2.1 How it works ................................................................................................................................................................. 8
2.2 Quick guide to connect to LoRaWAN server (OTAA) ............................................................................................. 9
2.3 Uplink Payload ............................................................................................................................................................ 14
2.3.1 Payload Analyze ................................................................................................................................................... 14
2.3.2 Payload Decoder file ............................................................................................................................................ 15
2.3.3 Historical Temperature and humidity of S31, FPORT=3（Since firmware 1.8.0） ........................................ 15
2.4Datalog Feature ........................................................................................................................................................... 17
2.4.1 Unix TimeStamp .................................................................................................................................................... 17
2.4.2 Set Device Time .................................................................................................................................................... 18
2.4.3 Poll sensor value ................................................................................................................................................... 18
2.4.4 Clear Flash Record ............................................................................................................................................... 18
2.4.5 Set system time ................................................................................................................................................... 19
2.4.6 Set Time Sync Mode ........................................................................................................................................... 19
2.5 Temperature & HumidityAlarm Feature ................................................................................................................. 19
2.6 Configure LSN50v2-S31 ........................................................................................................................................... 21
2.6.1 General Configure Commands ........................................................................................................................... 21
2.6.2 Sensor related commands .................................................................................................................................. 21
2.7 LED Status ................................................................................................................................................................. 23
2.8 Button Function .......................................................................................................................................................... 23
2.9 Firmware Change Log ............................................................................................................................................... 23
3. Battery & Power Consumption ...................................................................................................................................... 23
4. Use AT Command .......................................................................................................................................................... 23
4.1 Access AT Commands ............................................................................................................................................. 23
5. FAQ .................................................................................................................................................................................. 25
5.1 What is the frequency range of LSN50v2-S31? .................................................................................................... 25
5.2 What is the Frequency Plan? ................................................................................................................................... 25
5.3 How to update the firmware? ................................................................................................................................... 25
6. Trouble Shooting ............................................................................................................................................................ 26
6.1 AT Command input doesn't work ............................................................................................................................ 26
6.2 Abnormal temperature ................................................................................................................................................ 26
7. Order Info ........................................................................................................................................................................ 26
8. Packing Info ..................................................................................................................................................................... 26
9. Support ............................................................................................................................................................................. 26
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual


Table of Contents:
•1. Introduction
•1.1 What is LSN50V2-S31 LoRaWAN Temperature & Humidity Sensor
•1.2 Specifications
•1.3 Features
•1.4 Applications
•1.5 Pin Definitions and Switch
•1.5.1 Pin Definition
•1.5.2 Jumper JP2
•1.5.3 BOOT MODE / SW1
•1.5.4 Reset Button
•1.5.5 LED
•1.5.6 Probe Dimension
•1.6 Hardware Variant
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
•2. How to use LSN50v2-S31?
•2.1 How it works
•2.2 Quick guide to connect to LoRaWAN server (OTAA)
•2.3 Uplink Payload
•2.3.1 Payload Analyze
•Battery:
•Temperature:
•Humidity:
•Alarm Flag& MOD:
•2.3.2 Payload Decoder file
•2.3.3 Historical Temperature and humidity of S31, FPORT=3（Since firmware 1.8.0）
•2.4Datalog Feature
•2.4.1 Unix TimeStamp
•2.4.2 Set Device Time
•2.4.3 Poll sensor value
•2.4.4 Clear Flash Record
•2.4.5 Set system time
•2.4.6 Set Time Sync Mode
•2.5 Temperature & HumidityAlarm Feature
•2.6 Configure LSN50v2-S31
•2.6.1 General Configure Commands
•2.6.2 Sensor related commands
•Set Temperature Alarm Threshold:
•Set Humidity Alarm Threshold:
•Set Alarm Interval:
•Poll the Alarm settings:
•2.7 LED Status
•2.8 Button Function
•2.9 Firmware Change Log
•3. Battery & Power Consumption
•4. Use AT Command
•4.1 Access AT Commands
•5. FAQ
•5.1 What is the frequency range of LSN50v2-S31?
•5.2 What is the Frequency Plan?
•5.3 How to update the firmware?
•6. Trouble Shooting
•6.1 AT Command input doesn't work
•6.2 Abnormal temperature
•7. Order Info
•8. Packing Info
•9. Support
1. Introduction
1.1 What is LSN50V2-S31 LoRaWAN Temperature & Humidity Sensor
The Dragino LSN50v2-S31 is a LoRaWAN Temperature and Humidity Sensorfor Internet of Things solution. It
is used to measure the surrounding environment temperature and relative air humidity precisely, and then
upload to IoT server via LoRaWAN wireless protocol.
The temperature & humidity sensor used in LSN50v2-S31 is SHT31, which is fully calibrated, linearized, and
temperature compensated digital output from Sensirion, it provides a strong reliability and long-term stability. The
SHT31 is fixed in a waterproof anti-condensation casingfor long term use.
LSN50v2-S31 supports temperature and humidity alarm feature, user can get alarm for instant notice.
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
LSN50v2-S31 is powered by8500mAh Li-SOCI2 battery, It is designed for long term use up to 10 years. (Real-
world battery life depends on the use environment, update period. Please check related Power Analyze report).
Each LSN50v2-S31 is pre-load with a set of unique keys for LoRaWAN registration, register these keys to local
LoRaWAN server and it will auto connect after power on.
1.2 Specifications
Micro Controller:
• MCU: STM32L072xxxx
• Flash:128KB
• RAM:20KB
• EEPROM: 6KB
• Clock Speed: 32Mhz
Common DC Characteristics:
• Supply Voltage: built in 8500mAh Li-SOCI2 battery
• Operating Temperature: -40 ~ 85°C
Temperature Sensor:
• Range: -40 to + 80°C
• Accuracy: ±0.2 @ 0-90 °C
• Resolution: 0.1°C
• Long Term Shift: <0.03 °C/yr
Humidity Sensor:
• Range: 0 ~ 99.9% RH
• Accuracy: ± 2%RH ( 0 ~ 100%RH)
• Resolution: 0.01% RH
• Long Term Shift: <0.25 %RH/yr
LoRa Spec:
• Frequency Range, 
• Band 1 (HF): 862 ~ 1020 Mhz
• 168 dB maximum link budget.
• High sensitivity: down to -148 dBm.
• Bullet-proof front end: IIP3 = -12.5 dBm.
• Excellent blocking immunity.
• Built-in bit synchronizer for clock recovery.
• Preamble detection.
• 127 dB Dynamic Range RSSI.
• Automatic RF Sense and CAD with ultra-fast AFC.
• LoRaWAN 1.0.3 Specification
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
Power Consumption
• Sleeping Mode: 20uA
• LoRaWAN Transmit Mode: 125mA @ 20dBm 44mA @ 14dBm
1.3 Features
• LoRaWAN v1.0.3 Class A
• Ultra-low power consumption
• External 3 meters SHT31 probe
• Measure range -55°C ~ 125°C
• Temperature & Humidity alarm
• Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915/IN865
• AT Commands to change parameters
• Uplink on periodically or Interrupt
• Downlink to change configure
• 8500mAh Battery for long term use
1.4 Applications
• Wireless Alarm and Security Systems
• Home and Building Automation
• Industrial Monitoring and Control
• Long range Irrigation Systems.
1.5 Pin Definitions and Switch
The latest mother board for LSN50v2-S31 is :
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
1.5.1 Pin Definition
The device is pre-configured to connect to SHT31 sensor. The other pins are not used. If user want to know more
about other pins, please refer the user manual of LSn50v2 at:https://www.dropbox.com/sh/djkxs7mr17y94mi/
AABVlWbM9uzK9OA3mXyAT10Za?dl=0
1.5.2 Jumper JP2
Power on Device when put this jumper.
1.5.3 BOOT MODE / SW1
1. ISP: upgrade mode, device won't have any signal in this mode. but ready for upgrade firmware. LED won't
work. Firmware won't run.
2. Flash: work mode, device starts to work and send out console output for further debug
1.5.4 Reset Button
Press to reboot the device.
1.5.5 LED
It will flash:
1. When boot the device in flash mode
2. Send an uplink packet
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
1.5.6 Probe Dimension
1.6 Hardware Variant
Model Photo Description
LSN50v2-S31 External 3 meters SHT31 probe
LSN50v2 -S31B On device SHT31 Probe
2. How to use LSN50v2-S31?
2.1 How it works
The LSN50v2-S31 is working as LoRaWAN OTAA Class A end node. Each LSN50v2-S31 is shipped with a
worldwide unique set of OTAA and ABP keys. User needs to input the OTAA or ABP keys in the LoRaWAN network
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
server to register. Open the enclosure and power on the LSN50v2-S31, it will join the LoRaWAN network and start
to transmit data. The default period for each uplink is 20 minutes.
2.2 Quick guide to connect to LoRaWAN server (OTAA)
Here is an example for how to join the TTN LoRaWANServer. Below is the network structure, in this demo we use
DLOS8 as LoRaWAN gateway.
The DLOS8 is already set to connect to TTN. What the rest we need to is register the LSN50V2-S31 to TTN:
Step 1: Create a device in TTN with the OTAA keys from LSN50V2-S31.
Each LSN50V2-S31 is shipped with a sticker with the default device EUI as below:
You can enter this key in the LoRaWAN Server portal. Below is TTN screen shot:
Register the device：
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S31B LoRaWAN Temperature & Humidity Sensor User Manual
Add APP EUI and DEV EUI：
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S31B LoRaWAN Temperature & Humidity Sensor User Manual
Add APP EUI in the application：
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S31B LoRaWAN Temperature & Humidity Sensor User Manual
Add APP KEY
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S31B LoRaWAN Temperature & Humidity Sensor User Manual
Step 2: Power on LSN50v2-S31
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S31B LoRaWAN Temperature & Humidity Sensor User Manual
Step 3: LSN50V2-S31 will auto join to TTN network via the LoRaWAN coverage by DLOS8. After join success,
LSN50V2-S31 will start to uplink temperature value to server.
2.3 Uplink Payload
2.3.1 Payload Analyze
Normal Upload Payload:
LSN50v2-S31 use the same payload as LSn50v2 mod1, as below. （Since firmware version 1.8.0, the third to sixth
bytes are timestamps）
Size(bytes) 2 4 1 2 2
Value Battery Unix TimeStamp Alarm Flag Temperature Humidity
Battery:
Check the battery voltage.
Ex1: 0x0B45 = 2885mV
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Ex2: 0x0B49 = 2889mV
Temperature:
Example:
If payload is: 0105H: (0105 & 8000 == 0), temp = 0105H /10 = 26.1 degree
If payload is: FF3FH : (FF3F & 8000 == 1) , temp = (FF3FH - 65536)/10 = -19.3 degrees.
（FF3F & 8000：Judge whether the highest bit is 1, when the highest bit is 1, it is negative）
Humidity:
Read:0x(0197)=412 Value: 412 / 10=41.2, So 41.2%
Alarm Flag& MOD:
Example:
If payload & 0x01 = 0x01 --> This is an Alarm Message
If payload & 0x01 = 0x00 -->This is a normal uplink message, no alarm
If payload >> 2 = 0x00 --> means MOD=1, This is a sampling uplink message
If payload >> 2 = 0x31 --> means MOD=31, this message is a reply message for polling, this message
contains the alarm settings.see this link for detail. 
2.3.2 Payload Decoder file
In TTN, use can add a custom payload so it shows friendly.
In the page Applications --> Payload Formats --> Custom --> decoder to add the decoder from:
http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LSN50v2-S31/Decoder/
2.3.3 Historical Temperature and humidity of S31, FPORT=3（Since firmware 1.8.0）
S31 stores sensor values and users can retrieve these history values via thedownlink command.
The historical payload includes one or multiplies entries and every entry has the same payload as Real-Time
water flow status.
• Each data entry is 11 bytes and has the same structure asreal time water flow status, to save airtime and
battery, S31will send max bytes according to the current DR and Frequency bands.
For example, in the US915 band, the max payload for different DR is:
a) DR0:max is 11 bytes so one entry of data
b) DR1:max is 53 bytes so devices will upload 4 entries of data (total 44 bytes)
c) DR2:total payload includes 11 entries of data
d) DR3:total payload includes 22 entries of data.
If S31 doesn't have any data in the polling time. It will uplink 11 bytes of 0
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S31B LoRaWAN Temperature & Humidity Sensor User Manual
Downlink:
0x3164225B0064225D5805
Uplink:
00 00 00 00 E1 02 95 64 22 5B 37 00 00 00 00 E1 02 97 64 22 5B 74 00 00 00 00 E0 02 98 64 22 5B B0 00 00
00 00 E0 02 9C 64 22 5B EC 00 00 00 00 E0 02 9C 64 22 5C 28 00 00 00 00 DF 02 9D 64 22 5C 64 00 00 00 00
DF 02 9F 64 22 5C A0 00 00 00 00 DE 02 A0 64 22 5C DC 00 00 00 00 DE 02 A9 64 22 5D 18 00 00 00 00 DE 02
A4 64 22 5D 54
Parsed Value:
【Temperature,Humidity,Unix TimeStamp】
[22.5,66.1,2023-03-28 03:12:55],
[22.5,66.3,2023-03-28 03:13:56],
[22.4,66.4,2023-03-28 03:14:56],
[22.4,66.8,2023-03-28 03:15:56],
[22.4,66.8,2023-03-28 03:16:56],
[22.3,66.9,2023-03-28 03:17:56],
[22.3,67.1,2023-03-28 03:18:56]
[22.2,67.2,2023-03-28 03:19:56],
[22.2,68.1,2023-03-28 03:20:56],
[22.2,67.6,2023-03-28 03:21:56],
Serial port：
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S31B LoRaWAN Temperature & Humidity Sensor User Manual
2.4Datalog Feature
2.4.1 Unix TimeStamp
S31uses Unix TimeStamp format based on
Users can get this time from the link:https://www.epochconverter.com/:
Below is the converter example
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
2.4.2 Set Device Time
Through LoRaWAN MAC Command
Once S31Joined the LoRaWAN network, it will send the MAC command (DeviceTimeReq) and the server will
reply with (DeviceTimeAns) to send the current time to S31. If S31fails to get the time from the server,S31will use
the internal time and wait for the next time request.
Note:LoRaWAN Server needs to support LoRaWAN v1.0.3(MAC v1.0.3) or higher to support this MAC
command feature.
2.4.3 Poll sensor value
Users can poll sensor values based on timestamps. Below is the downlink command.
Downlink Command to poll Open/Close status (0x31)
1byte 4bytes 4bytes 1byte
31 Timestamp start Timestamp end Uplink Interval
Timestamp start and Timestamp end-use Unix TimeStamp format as mentioned above. Devices will reply with all
data logs during this period, using the uplink interval.
For example, downlink command 
Is to check 2021/11/12 12:00:00 to 2021/11/12 15:00:00's data
Uplink Internal =5s，means CPL01 will send one packet every 5s. range 5~255s.
2.4.4 Clear Flash Record
Feature: Clear flash storage for data log feature.
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
AT Command: AT+CLRDTA
Command Example Function Response
AT+CLRDTA Clear date record Clear all stored sensor data…
OK
2.4.5 Set system time
Feature: Set system time, Unix format.See here for format detail.
AT Command:
Command Example Function Response
AT+TIMESTAMP=1611104352 Set System time to 2021-01-20 00:59:12 OK
Downlink Command:
0x306007806000 // Set timestamp to 0x(6007806000),Same as AT+TIMESTAMP=1611104352
2.4.6 Set Time Sync Mode
Feature: Enable/Disable Sync system time via LoRaWAN MAC Command (DeviceTimeReq), LoRaWAN server
must support v1.0.3 protocol to reply to this command.
SYNCMOD is set to 1 by default. If user wants to set a different time from the LoRaWAN server, the user needs to
set this to 0.
AT Command:
Command Example Function Response
AT+SYNCMOD=1 Enable Sync system time via LoRaWAN MAC Command (DeviceTimeReq)
The default is zero time zone.
OK
AT+SYNCMOD=1,8 Enable Sync system time via LoRaWAN MAC Command (DeviceTimeReq)
Set to East eight-time zone.
OK
AT+SYNCMOD=1,-12 Enable Sync system time via LoRaWAN MAC Command (DeviceTimeReq)
Set to West Twelve Time Zone.
OK
Downlink Command:
0x28 01 // Same As AT+SYNCMOD=1
0x28 01 08 // Same As AT+SYNCMOD=1,8
0x28 01 F4 // Same As AT+SYNCMOD=1,-12
0x28 00 // Same As AT+SYNCMOD=0
2.5 Temperature & HumidityAlarm Feature
LSN50V2-S31 work flow with Alarm feature.
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User Manual for LoRaWAN End Nodes - LSN50v2-S31-
S31B LoRaWAN Temperature & Humidity Sensor User Manual
User can use AT+SHTEMPand AT+SHHUMcommand to set the alarm low limit or high limit. Device will check
the temperature & Humidity every minute, if the temperature lower than low limit or greater than high limit. LSN50v2-
S31 will send an Alarm packet base on Confirmed Uplink Modeto server.
Below is an example of the Alarm Packet.
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