Table of Contents :

• 1. Introduction
  • 1.1 What is LoRaWAN LiDAR Distance Auto-Clean Sensor
  • 1.2 ​Features
  • 1.3 Specification
  • 1.4 Applications
  • 1.5 Sleep mode and working mode
  • 1.6 Button & LEDs
  • 1.7 BLE connection
  • 1.8 Pin Definitions
  • 1.9 Mechanical
    • 1.9.1 for LB version
    • 1.9.2 for LS version
• 2. Configure LDS25-LB/LS to connect to LoRaWAN network
  • 2.1 How it works
  • 2.2 ​Quick guide to connect to LoRaWAN server (OTAA)
  • 2.3 ​Uplink Payload
    • 2.3.1 Device Status, FPORT=5
    • 2.3.2 Uplink Payload, FPORT=2
      • Battery Info
      • DS18B20 Temperature sensor
      • Distance
      • Distance signal strength
      • Interrupt Pin & Interrupt Level
      • LiDAR temp
      • Message Type
    • 2.3.3 Historical measuring distance, FPORT=3
    • 2.3.5 Decode payload in The Things Network
  • 2.4 ​Show Data in DataCake IoT Server
  • 2.5 Datalog Feature
    • 2.5.1 Ways to get datalog via LoRaWAN
    • 2.5.2 Unix TimeStamp
    • 2.5.3 Set Device Time
    • 2.5.4 Poll sensor value
  • 2.6 Frequency Plans
  • 2.7 LiDAR ToF Measurement
    • 2.7.1 Principle of Distance Measurement
    • 2.7.2 Distance Measurement Characteristics
    • 2.7.3 Notice of usage
    • 2.7.4 Reflectivity of different objects
• 3. Configure LDS25-LB/LS
  • 3.1 Configure Methods
  • 3.2 General Commands
  • 3.3 Commands special design for LDS25-LB/LS
    • 3.3.1 Set Transmit Interval Time
    • 3.3.2 Set Interrupt Mode
    • 3.3.3 Set Power Output Duration
    • 3.3.4 Get or set the automatic cleaning interval
• 4. Battery & Power Consumption
• 5. OTA Firmware update
• 6. FAQ
  • 6.1 What is the frequency plan for LDS25-LB/LS?
• 7. Trouble Shooting
  • 7.1 AT Command input doesn't work
  • 7.2 Significant error between the output distant value of LiDAR and actual distance
• 8. Order Info
• 9. ​Packing Info
• 10. Support

1. Introduction

1.1 What is LoRaWAN LiDAR Distance Auto-Clean Sensor

The Dragino LDS25-LB/LS is a LoRaWAN LiDAR (Time of Flight) Distance Auto-Clean Sensor for Internet of Things solution. It is capable to measure the distance to an object as close as 10 centimeters (+/- 6cm up to 6m) and as far as 25 meters (+/-1% starting at 25m)!. The LiDAR probe uses laser induction technology for distance measurement.

It has a unique dust removal brush structure built in, and the radar drives the dust removal brush to complete the optical mirror dust removal operation, and the user can customize the dust removal confguration.

The LDS25-LB/LS can be applied to scenarios such as horizontal distance measurement, parking management system, object proximity and presence detection, intelligent trash can management system, robot obstacle avoidance, automatic control, sewer, etc.

It detects the distance between the measured object and the sensor, and uploads the value via wireless to LoRaWAN IoT Server.

The LoRa wireless technology used in LDS25-LB/LS allows device to send data and reach extremely long ranges at low data-rates. It provides ultra-long range spread spectrum communication and high interference immunity whilst minimizing current consumption.

LDS25-LB/LS supports BLE configure and wireless OTA update which make user easy to use.

LDS25-LB/LS is powered by 8500mAh Li-SOCI2 battery or solar powered + Li-ion battery , it is designed for long term use up to 5 years.

Each LDS25-LB/LS is pre-load with a set of unique keys for LoRaWAN registrations, register these keys to local LoRaWAN server and it will auto connect after power on.

1.2 ​Features

• LoRaWAN 1.0.3 Class A
• Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915/IN865
• Ultra-low power consumption
• Laser technology for distance detection
• Self-contained Auto-clean function
• Measure Distance: 0.1m~25m
• Accuracy :  ±6cm@(0.1m-6m), ±1%@(6m-25m)
• Resolution : 1cm
• FOV : 3°
• Monitor Battery Level
• Support Bluetooth v5.1 and LoRaWAN remote configure
• Support wireless OTA update firmware
• AT Commands to change parameters
• Downlink to change configure
• 8500mAh Li/SOCl2 Battery (LDS25-LB)
• Solar panel + 3000mAh Li-ion battery (LDS25-LS)

1.3 Specification

Common DC Characteristics:

• Supply Voltage: Built-in Battery , 2.5v ~ 3.6v
• Operating Temperature: -40 ~ 85°C

Probe Specification:

• Storage temperature: -30℃~80℃
• Operating temperature : -20℃~60℃
• Measure Distance:
  • 0.1m ~ 25m @ 90% Reflectivity
  • 0.1m ~ 12m @ 10% Reflectivity
• Accuracy : ±6cm@(0.1m-6m), ±1%@(6m-25m)
• Distance resolution : 1cm
• Ambient light immunity : 100klux
• Enclosure rating : IP5X
• Light source : VCSEL
• Central wavelength : 850nm
• FOV : 3°
• Material of enclosure : ABS+PC
• Wire length : 120cm

LoRa Spec:

• Frequency Range,  Band 1 (HF): 862 ~ 1020 Mhz
• Max +22 dBm constant RF output vs.
• RX sensitivity: down to -139 dBm.
• Excellent blocking immunity

Battery:

• Li/SOCI2 un-chargeable battery
• Capacity: 8500mAh
• Self-Discharge: <1% / Year @ 25°C
• Max continuously current: 130mA
• Max boost current: 2A, 1 second

Power Consumption

• Sleep Mode: 5uA @ 3.3v
• LoRa Transmit Mode: 125mA @ 20dBm, 82mA @ 14dBm

1.4 Applications

• Horizontal distance measurement
• Parking management system
• Object proximity and presence detection
• Intelligent trash can management system
• Robot obstacle avoidance
• Automatic control
• Sewer

1.5 Sleep mode and working mode

Deep Sleep Mode: Sensor doesn't have any LoRaWAN activate. This mode is used for storage and shipping to save battery life.

Working Mode: In this mode, Sensor will work as LoRaWAN Sensor to Join LoRaWAN network and send out sensor data to server. Between each sampling/tx/rx periodically, sensor will be in IDLE mode), in IDLE mode, sensor has the same power consumption as Deep Sleep mode.

1.6 Button & LEDs

1.7 BLE connection

LDS25-LB/LS support BLE remote configure.

BLE can be used to configure the parameter of sensor or see the console output from sensor. BLE will be only activate on below case:

• Press button to send an uplink
• Press button to active device.
• Device Power on or reset.

If there is no activity connection on BLE in 60 seconds, sensor will shut down BLE module to enter low power mode.

1.8 Pin Definitions

1.9 Mechanical

1.9.1 for LB version

 Probe Mechanical:

1.9.2 for LS version

2. Configure LDS25-LB/LS to connect to LoRaWAN network

2.1 How it works

The LDS25-LB/LS is configured as LoRaWAN OTAA Class A mode by default. It has OTAA keys to join LoRaWAN network. To connect a local LoRaWAN network, you need to input the OTAA keys in the LoRaWAN IoT server and press the button to activate the LDS25-LB/LS. It will automatically join the network via OTAA and start to send the sensor value. The default uplink interval is 20 minutes.

2.2 ​Quick guide to connect to LoRaWAN server (OTAA)

Following is an example for how to join the TTN v3 LoRaWAN Network. Below is the network structure; we use the LPS8v2  as a LoRaWAN gateway in this example. 

The LPS8v2 is already set to connected to TTN network , so what we need to now is configure the TTN server.

Step 1: Create a device in TTN with the OTAA keys from LDS25-LB/LS.

Each LDS25-LB/LS 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:

Create the application.

Add devices to the created Application.

Enter end device specifics manually.

Add DevEUI and AppKey.

Customize a platform ID for the device.

Step 2: Add decoder.

In TTN, user can add a custom payload so it shows friendly reading.

Click this link to get the decoder: https://github.com/dragino/dragino-end-node-decoder/tree/main/

Below is TTN screen shot:

Step 3: Activate on LDS25-LB/LS

Press the button for 5 seconds to activate the LDS25-LB/LS.

Green led will fast blink 5 times, device will enter OTA mode for 3 seconds. And then start to JOIN LoRaWAN network. Green led will solidly turn on for 5 seconds after joined in network.

After join success, it will start to upload messages to TTN and you can see the messages in the panel.

2.3 ​Uplink Payload

2.3.1 Device Status, FPORT=5

Users can use the downlink command(0x26 01) to ask LDS25-LB/LS to send device configure detail, include device configure status. LDS25-LB/LS will uplink a payload via FPort=5 to server.

The Payload format is as below.

Example parse in TTNv3:

Sensor Model: For LDS25-LB/LS, this value is 0x3E

Firmware Version: 0x0100, Means: v1.0.0 version

Frequency Band:

0x01: EU868

0x02: US915

0x03: IN865

0x04: AU915

0x05: KZ865

0x06: RU864

0x07: AS923

0x08: AS923-1

0x09: AS923-2

0x0a: AS923-3

0x0b: CN470

0x0c: EU433

0x0d: KR920

0x0e: MA869

Sub-Band:

AU915 and US915:value 0x00 ~ 0x08

CN470: value 0x0B ~ 0x0C

Other Bands: Always 0x00

Battery Info:

Check the battery voltage.

Ex1: 0x0B45 = 2885mV

Ex2: 0x0B49 = 2889mV

2.3.2 Uplink Payload, FPORT=2

Battery Info

Check the battery voltage for LDS25-LB/LS.

Ex1: 0x0C72 = 3186mV

Ex2: 0x0B49 = 2889mV

DS18B20 Temperature sensor

This is optional, user can connect external DS18B20 sensor to the +3.3v, 1-wire and GND pin . and this field will report 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.

Distance

Represents the distance value of the measurement output, the default unit is cm, and the value range parsed as a decimal number is 0-2500. In actual use, when the signal strength value Strength.

Example:

If the data you get from the register is 0x0B 0xEA, the distance between the sensor and the measured object is 0E38(H) = 3640 (D)/10 = 364.0cm.

Distance signal strength

Refers to the signal strength, the default output value will be between 0-65535. When the distance measurement gear is fixed, the farther the distance measurement is, the lower the signal strength; the lower the target reflectivity, the lower the signal strength. When Strength is greater than 100 and not equal to 65535, the measured value of Dist is considered credible.

Example:

If payload is: 016C(H)=364(D), distance signal strength=364, 364>100,364≠65535, the measured value of Dist is considered credible.

Customers can judge whether they need to adjust the environment based on the signal strength.

1) When the sensor detects valid data:

2) When the sensor detects invalid data:

3) When the sensor is not connected:

Interrupt Pin & Interrupt Level

This data field shows if this packet is generated by interrupt or not. Click here for the hardware and software set up.

Note: The Internet Pin is a separate pin in the screw terminal. See pin mapping of GPIO_EXTI .

Example:

If byte[0]&0x01=0x00 : Normal uplink packet.

If byte[0]&0x01=0x01 : Interrupt Uplink Packet.

LiDAR temp

Characterize the internal temperature value of the sensor.

Example: 
If payload is: 1C(H) <<24>>24=26(D),LiDAR temp=26℃.
If payload is: F2(H) <<24>>24=-14(D),LiDAR temp=-14℃.

Message Type

2.3.3 Historical measuring distance, FPORT=3

LDS25-LB/LS 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 measuring distance.

Interrupt flag & Interrupt level:

• Each data entry is 11 bytes and has the same structure as Uplink Payload, to save airtime and battery, LDS25-LB/LS 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 LDS25-LB/LS doesn't have any data in the polling time. It will uplink 11 bytes of 0

Downlink:

0x31 67 05 E4 CC 67 05 EA A8 05

Uplink:

40FF0CEE007E1B6705E50040FF0CB2007B1B6705E62C40FF0CA800811B6705E75840FF0CD0007C1B6705E88440FF0CE400791B6705E9B0

Parsed Value:

[DISTANCE , DISTANCE_SIGNAL_STRENGTH，LIDAR_TEMP，EXTI_STATUS , EXTI_FLAG , TIME]

[331,126,27,Low,False,2024-10-09 02:05:52],

[325,123,27,Low,False,2024-10-09 02:10:52],

[324,129,27,Low,False,2024-10-09 02:15:52],

[328,124,27,Low,False,2024-10-09 02:20:52],

[330,121,27,Low,False,2024-10-09 02:25:52],

[342,122,27,Low,False,2024-10-09 02:30:52],

[338,127,27,Low,False,2024-10-09 02:35:52],

[328,126,27,Low,False,2024-10-09 02:40:52]

History read from serial port：

2.3.5 Decode payload in The Things Network

While using TTN network, you can add the payload format to decode the payload.

2.4 ​Show Data in DataCake IoT Server

Step 3: Create an account or log in Datacake.

Step 4: Search the LDS25-LB/LS and add DevEUI.

After added, the sensor data arrive TTN V3, it will also arrive and show in Datacake.

2.5 Datalog Feature

Datalog Feature is to ensure IoT Server can get all sampling data from Sensor even if the LoRaWAN network is down. For each sampling, LDS25-LB/LS will store the reading for future retrieving purposes.

2.5.1 Ways to get datalog via LoRaWAN

Set PNACKMD=1, LDS25-LB/LS will wait for ACK for every uplink, when there is no LoRaWAN network, LDS25-LB/LS will mark these records with non-ack messages and store the sensor data, and it will send all messages (10s interval) after the network recovery.

• a) LDS25-LB/LS will do an ACK check for data records sending to make sure every data arrive server.

• b) LDS25-LB/LS will send data in CONFIRMED Mode when PNACKMD=1, but LDS25-LB/LS won't re-transmit the packet if it doesn't get ACK, it will just mark it as a NONE-ACK message. In a future uplink if LDS25-LB/LS gets a ACK, LDS25-LB/LS will consider there is a network connection and resend all NONE-ACK messages. 

2.5.2 Unix TimeStamp

LDS25-LB/LS uses Unix TimeStamp format based on

User can get this time from link:  https://www.epochconverter.com/ :

Below is the converter example

So, we can use AT+TIMESTAMP=1611889405 or downlink 3060137afd00 to set the current time 2021 – Jan -- 29 Friday 03:03:25

2.5.3 Set Device Time

User need to set SYNCMOD=1 to enable sync time via MAC command.

Once LDS25-LB/LS Joined LoRaWAN network, it will send the MAC command (DeviceTimeReq) and the server will reply with (DeviceTimeAns) to send the current time to LDS25-LB/LS. If LDS25-LB/LS fails to get the time from the server, LDS25-LB/LS will use the internal time and wait for next time request (AT+SYNCTDC to set the time request period, default is 10 days).

Note: LoRaWAN Server need to support LoRaWAN v1.0.3(MAC v1.0.3) or higher to support this MAC command feature, Chirpstack,TTN V3 v3 and loriot support but TTN V3 v2 doesn't support. If server doesn't support this command, it will through away uplink packet with this command, so user will lose the packet with time request for TTN V3 v2 if SYNCMOD=1.

2.5.4 Poll sensor value

Users can poll sensor values based on timestamps. Below is the downlink command.

2.6 Frequency Plans

The LDS25-LB/LS uses OTAA mode and below frequency plans by default. Each frequency band use different firmware, user update the firmware to the corresponding band for their country.

http://wiki.dragino.com/xwiki/bin/view/Main/End%20Device%20Frequency%20Band/

2.7 LiDAR ToF Measurement

2.7.1 Principle of Distance Measurement

The LiDAR probe is based on TOF, namely, Time of Flight principle. To be specific, the product emits modulation wave of near infrared ray on a periodic basis, which will be reflected after contacting object. The product obtains the time of flight by measuring round-trip phase difference and then calculates relative range between the product and the detection object, as shown below.

2.7.2 Distance Measurement Characteristics

With optimization of light path and algorithm, The LiDAR probe has minimized influence from external environment on distance measurement performance. Despite that, the range of distance measurement may still be affected by the environment illumination intensity and the reflectivity of detection object. 

TF02-Pro-W Detection Angle Diagram:

2.7.3 Notice of usage

Possible invalid /wrong reading for LiDAR ToF tech:

• Measure high reflectivity object such as: Mirror, Smooth ceramic tile, static milk surface, will have possible wrong readings.
• While there is transparent object such as glass, water drop between the measured object and the LiDAR sensor, the reading might be wrong.
• The LiDAR probe is cover by dirty things; the reading might be wrong. In this case, need to clean the probe.
• The sensor window is made by Acrylic. Don't touch it with alcohol material. This will destroy the sensor window.

2.7.4 Reflectivity of different objects

3. Configure LDS25-LB/LS

3.1 Configure Methods

LDS25-LB/LS supports below configure method:

• AT Command via Bluetooth Connection (Recommended): BLE Configure Instruction.

• AT Command via UART Connection : See UART Connection.

• LoRaWAN Downlink.  Instruction for different platforms: See IoT LoRaWAN Server section.

3.2 General Commands

These commands are to configure:

• General system settings like: uplink interval.

• LoRaWAN protocol & radio related command.

They are same for all Dragino Devices which support DLWS-005 LoRaWAN Stack. These commands can be found on the wiki:

http://wiki.dragino.com/xwiki/bin/view/Main/End%20Device%20AT%20Commands%20and%20Downlink%20Command/

3.3 Commands special design for LDS25-LB/LS

These commands only valid for LDS25-LB/LS, as below:

3.3.1 Set Transmit Interval Time

• Example 1: Downlink Payload: 0100001E       // Set Transmit Interval (TDC) = 30 seconds

• Example 2: Downlink Payload: 0100003C      // Set Transmit Interval (TDC) = 60 seconds  

   

3.3.2 Set Interrupt Mode

Feature, Set Interrupt mode for pin of GPIO_EXTI.

When AT+INTMOD=0 is set, GPIO_EXTI is used as a digital input port.

AT Command: AT+INTMOD

Downlink Command: 0x06

Format: Command Code (0x06) followed by 3 bytes.

This means that the interrupt mode of the end node is set to 0x000003=3 (rising edge trigger), and the type code is 06.

• Example 1: Downlink Payload: 06000000       //  Turn off interrupt mode

• Example 2: Downlink Payload: 06000003      //   Set the interrupt mode to rising edge trigger

3.3.3 Set Power Output Duration

Control the output duration 3V3(pin of VBAT_OUT) . Before each sampling, device will

1. first enable the power output to external sensor,

2. keep it on as per duration, read sensor value and construct uplink payload

3. final, close the power output.

AT Command: AT+3V3T

Downlink Command: 0x07
Format: Command Code (0x07) followed by 3 bytes.

The first byte is 01,the second and third bytes are the time to turn on.

• Example 1: Downlink Payload: 07 01 00 00     --->   AT+3V3T=0
• Example 2: Downlink Payload: 07 01 01 F4      --->  AT+3V3T=500
• Example 3: Downlink Payload: 07 01 FF FF      --->  AT+3V3T=65535

3.3.4 Get or set the automatic cleaning interval

Function: It can be set to auto-clean once before each uplink packet or set to auto-clean at regular intervals. (Unit: minute)

Note:If you set it to automatically clean once per uplink packet, it will shorten the length of time that the silicone on the wipers that the sensors can be used to clean is available, so it is recommended to use wipers that are activated once a day. (The factory default is to activate every 1440min)

AT Command: AT+REMODUST

Downlink Command: 0x08 02

Format: Command Code (0x08 02) followed by 4 bytes.

• Example 1: Downlink Payload: 08 02 01 01 05 A0       --->   AT+REMODUST=1,1,1440
• Example 2: Downlink Payload: 08 02 01 01 02 D0       --->  AT+REMODUST=1,1,720
• Example 3: Downlink Payload: 08 02 02 01 00 00        --->  AT+REMODUST=2,1,0
• Example 4: Downlink Payload: 08 02 02 02 00 00        --->  AT+REMODUST=2,2,0
• Example 5: Downlink Payload: 08 01                            --->  AT+REMODUST

4. Battery & Power Consumption

LDS25-LB use ER26500 + SPC1520 battery pack and LDS25-LS use 3000mAh Recharable Battery with Solar Panel. See below link for detail information about the battery info and how to replace.

Battery Info & Power Consumption Analyze .

5. OTA Firmware update

User can change firmware LDS25-LB/LS to:

• Change Frequency band/ region.

• Update with new features.

• Fix bugs. 

Firmware and changelog can be downloaded from : Firmware download link

Methods to Update Firmware:

• (Recommanded way) OTA firmware update via wireless:  http://wiki.dragino.com/xwiki/bin/view/Main/Firmware%20OTA%20Update%20for%20Sensors/

• Update through UART TTL interface: Instruction.

6. FAQ

6.1 What is the frequency plan for LDS25-LB/LS?

LDS25-LB/LS use the same frequency as other Dragino products. User can see the detail from this link:  Introduction

7. Trouble Shooting

7.1 AT Command input doesn't work

In the case if user can see the console output but can't type input to the device. Please check if you already include the ENTER while sending out the command. Some serial tool doesn't send ENTER while press the send key, user need to add ENTER in their string. 

7.2 Significant error between the output distant value of LiDAR and actual distance

8. Order Info

Part Number: LDS25-LB-XX or LDS25-LS-XX

XX: 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

9. ​Packing Info

Package Includes:

• LDS25-LB or LDS25-LS LoRaWAN LiDAR ToF Distance Sensor x 1

Dimension and weight:

• Device Size: cm

• Device Weight: g

• Package Size / pcs : cm

• Weight / pcs : g

10. Support

• Support is provided Monday to Friday, from 09:00 to 18:00 GMT+8. Due to different timezones 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 Support@dragino.cc.