DRAGINO LSN50v2-D20 LoRaWAN Temperature Sensor User Manual
- June 6, 2024
- DRAGINO
Table of Contents
DRAGINO LSN50v2-D20 LoRaWAN Temperature
**Sensor User Manual**
Introduction
1.1 What is LSN50V2-D20 LoRaWAN Temperature Sensor
The Dragino LSN50v2-D20 is a LoRaWAN Temperature Sensor for Internet of Things solution. It can be used to measure the temperature of air, liquid or object, and then upload to IoT server via LoRaWAN wireless protocol.
The temperature sensor used in LSN50v2-D20 is DS18B20, which can measure -55°C ~ 125°C with accuracy ±0.5°C (max ±2.0 °C). The sensor cable is made by Silica Gel, and the connection between metal probe and cable is double compress for waterproof, moisture-proof and anti-rust for long term usage.
LSN50v2-D20 supports temperature alarm feature, user can set temperature alarm for instant notice.
LSN50v2-D20 is powered by, it is designed for long term use up to 10 years. (Actually Battery life depends on the use environment, update period. Please check related Power Analyze report). Each LSN50v2-D20 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: STM32L072CZT6
➢ Flash:192KB
➢ 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: -55 to + 125°C
➢ Accuracy ±0.5°C (max ±2.0 °C).
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
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 DS18B20 Probe (default 2meters)
✓ Measure range -55°C ~ 125°C
✓ Temperature alarm
✓ Bands: CN470/EU433/KR920/US915 EU868/AS923/AU915/IN865
✓ AT Commands to change parameters
✓ Uplink on periodically or Interrupt
✓ Downlink to change configure
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
1.5.1 Pin Definition
The device is pre-configured to connect to DS18B20 sensor. The other pins are not used. If user want to know more about other pins, please refer the user manual of LSn50v2 at:
http://www.dragino.com/downloads/index.php?dir=LSN50-LoRaST/
1.5.2 Jumper JP2
Power on Device when put this jumper
1.5.3 BOOT MODE / SW1
- 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.
- 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:
- When boot the device in flash mode
- Send an uplink packet
1.6 Hardware Change log
LSN50v2-D20 v1.0:
Release.
How to use LSN50v2-D20?
2.1 How it works?
The LSN50v2-D20 is working as LoRaWAN OTAA Class A end node. Each LSN50v2-D20 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 server to register. Open the enclosure and power on the LSN50v2-D20, 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-D20 to TTN:
Step 1: Create a device in TTN with the OTAA keys from LSN50V2-D20.
Each LSN50V2-D20 is shipped with a sticker with the default device EUI as
below:
Input these keys in their LoRaWAN Server portal. Below is TTN screen shot:
Add APP EUI in the application
Add APP KEY and DEV EUI
Step 2: Power on LSN50V2-D20
Step 3: LSN50V2-D20 will auto join to TTN network via the LoRaWAN coverage by DLOS8. After join success, LSN50V2-D20 will start to uplink temperature value to server.
2.3 Uplink Payload
2.3.1 Payload Analyze
Normal Upload Payload:
LSN50v2-D20 use the same payload as LSn50v2 mod1, as below.
Battery:
Check the battery voltage.
Ex1: 0x0B45 = 2885mV
Ex2: 0x0B49 = 2889mV
Temperature:
Example:
If payload is: 0105H: (0105 & FC00 == 0), temp = 0105H /10 = 26.1 degree
If payload is: FF3FH : (FF3F & FC00 == 1) , temp = (FF3FH – 65536)/10 = -19.3
degrees.
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-D20/Decoder/
2.4 Temperature Alarm Feature
LSN50V2-D20 work flow with Alarm feature.
User can use AT+18ALARM command to set the alarm low limit or high limit. Device will check the temperature every minute, if the temperature lower than low limit or greater than high limit. LSN50v2-D20 will send an Alarm packet base on Confirmed Uplink Mode to server.
Below is an example of the Alarm Packet.
2.5 Configure LSN50v2-D20
LSN50V2-D20 supports configuration via LoRaWAN downlink command or AT Commands.
➢ Downlink command instructions for different platform:
http://wiki.dragino.com/index.php?title=Main_Page#Use_Note_for_Server
➢ AT Command Access Instructions:
LINK
There are two parts of commands: General one and Special for this model.
2.5.1 General Configure Commands
These commands are to configure:
✓ General system settings like: uplink interval.
✓ LoRaWAN protocol & radio related command.
These commands can be found on the wiki:
http://wiki.dragino.com/index.php?title=End_Device_AT_Commands_and_Downlink_Commands
2.5.2 Sensor related commands:
Set Alarm Threshold:
➢ AT Command:
AT+18ALARM=min,max
⊕ When min=0, and max≠0, Alarm higher than max
⊕ When min≠0, and max=0, Alarm lower than min
⊕ When min≠0 and max≠0, Alarm higher than max or lower than min
Example:
AT+18ALARM=-10,30 // Alarm when < -10 or higher than 30.
➢ Downlink Payload:
0x(0B F6 1E) // Same as AT+18ALARM=-10,30
(note: 0x1E= 30, 0xF6 means: 0xF6-0x100 = -10)
Set Alarm Interval:
The shortest time of two Alarm packet. (unit: min)
➢ AT Command:
AT+ATDC=30 // The shortest interval of two Alarm packets is 30 minutes, Means
is there is an alarm packet uplink, there won’t be another one in the next 30
minutes.
➢ Downlink Payload:
0x(0D 00 1E) —> Set AT+ATDC=0x 00 1E = 30 minutes
Poll the Alarm settings:
Send a LoRaWAN downlink to ask device send Alarm settings.
➢ Downlink Payload:
0x0E 01
Example:
Explain:
➢ Alarm & MOD bit is 0x7C, 0x7C >> 2 = 0x31: Means this message is the Alarm settings message.
2.6 LED Status
LSN50-v2-D20 has an internal LED, it will active in below situation:
➢ LED will fast blink 5 times when boot, this means the temperature sensor is
detected
➢ After the fast blinks on boot, the LED will flash once which means device is
trying to send Join Packet to the network.
➢ If device successful join LoRaWAN network, the LED will be solid on for 5
seconds.
2.7 Button Function
Internal RESET button:
Press this button will reboot the device. Device will process OTAA Join to network again.
2.8 Firmware Change Log
Battery Info
The LSN50v2-D20 battery is a combination of a 8500mAh ER26500 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.
The battery is designed to last for more than 10 years for the LSN50v2-D20.
The battery related documents can be found as below: http://www.dragino.com/downloads/index.php?dir=datasheet/Battery/ER26500/
The connector is as below incase user want to use their own battery
There are several parameters affect the battery power. Please see consumption report from here for the detail explain:
http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LSN50v2-D20/Test_Report/
Use AT Command
4.1 Access AT Command
User can use a USB to TTL adapter to connect to LSN50V2-D20 to use AT command to configure the device. Example is as below:
FAQ
5.1 What is the frequency range of LSN50v2-D20?
Different LSN50V2-D20 version supports different frequency range, below is the table for the working frequency and recommend bands for each model:
5.2 What is the Frequency Plan?
Please refer Dragino End Node Frequency Plan: http://wiki.dragino.com/index.php?title=End_Device_Frequency_Band
5.3 How to update the firmware?
User can upgrade the firmware for 1) bug fix, 2) new feature release or 3)
change frequency plan.
Please see this link for how to upgrade:
http://wiki.dragino.com/index.php?title=Firmware_Upgrade_Instruction_for_STM32_base_products#Hardware_Upgrade_Method_Support_List
Order Info
Part Number: LSN50V2-D20-XXX
XXX: The default frequency band
✓ AS923: LoRaWAN AS923 band
✓ AU915: LoRaWAN AU915 band
✓ EU433: LoRaWAN EU433 band
✓ EU868: LoRaWAN EU868 band
✓ KR920: LoRaWAN KR920 band
✓ US915: LoRaWAN US915 band
✓ IN865: LoRaWAN IN865 band
✓ CN470: LoRaWAN CN470 band
Packing Info
Package Includes:
✓ LSN50v2-D20 LoRaWAN Temperature Sensor x 1
Dimension and weight:
✓ Device Size:
✓ Device Weight:
✓ Package Size:
✓ Package Weight:
Support
➢ Support is provided Monday to Friday, from 09:00 to 18:00 GMT+8. Due to
different time zones we cannot offer live support. However, your questions
will be answered as soon as possible in the before-mentioned schedule.
➢ 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
References
- Dragino :: Open Source WiFi, Linux Appliance
- Dragino Download Server ./downloads/datasheet/Battery/ER26500/
- Dragino Download Server ./downloads/LoRa_End_Node/LSN50v2-D20/Decoder/
- Dragino Download Server ./downloads/LSN50-LoRaST/
- DLOS8 Outdoor LoRaWAN Gateway
- The Things Network
- The Things Network
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