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Table of Contents:

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1. Introduction

1.1 What is WL03A-NB NB-IoT None-Position Rope Type Water Leak Controller

The Dragino WL03A-NB is a NB-IoT None-Position Rope Type Water Leak Controller. User can lay the WL03A-NB + Water Leak Cable on the ground to detect water leakage. The water leak cable is sensitivity, when there is water over the leak cable. WL03A-NB will indicates a water leak event and uplink to IoT server via NB-IoT network.

The WL03A-NB will send periodically data every 2 hours as well as for each water leak event. It also counts the water leak times and calculate last water leak duration.

WL03A-NB supports different uplink methods including MQTT, MQTTs, UDP & TCP for different application requirement, and support uplinks to various IoT Servers.

WL03A-NB supports BLE configure and OTA update which make user easy to use.

WL03A-NB is powered by 8500mAh Li-SOCI2 battery, it is designed for long-term use up to several years.

WL03A-NB has optional built-in SIM card and default IoT server connection version. Which makes it works with simple configuration.

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1.2 ​Features

  • NB-IoT Bands: B1/B2/B3/B4/B5/B8/B12/B13/B17/B18/B19/B20/B25/B28/B66/B70/B85 @H-FDD
  • Ultra-low power consumption
  • Upload water flow volume
  • Water Leak detect
  • Multiply Sampling and one uplink
  • Support Bluetooth v5.1 remote configure and update firmware
  • Uplink on periodically
  • Downlink to change configure
  • 8500mAh Battery for long term use
  • Nano SIM card slot for NB-IoT SIM


1.3 Specification

Common DC Characteristics:

  • Supply Voltage: 2.5v ~ 3.6v
  • Operating Temperature: -40 ~ 85°C

NB-IoT Spec:

NB-IoT Module: BC660K-GL

Support Bands:

  • B1 @H-FDD: 2100MHz
  • B2 @H-FDD: 1900MHz
  • B3 @H-FDD: 1800MHz
  • B4 @H-FDD: 2100MHz
  • B5 @H-FDD: 860MHz
  • B8 @H-FDD: 900MHz
  • B12 @H-FDD: 720MHz
  • B13 @H-FDD: 740MHz
  • B17 @H-FDD: 730MHz
  • B18 @H-FDD: 870MHz
  • B19 @H-FDD: 870MHz
  • B20 @H-FDD: 790MHz
  • B25 @H-FDD: 1900MHz
  • B28 @H-FDD: 750MHz
  • B66 @H-FDD: 2000MHz
  • B70 @H-FDD: 2000MHz
  • B85 @H-FDD: 700MHz


  • 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

  • STOP Mode: 10uA @ 3.3v
  • Max transmit power: 350mA@3.3v


1.4 Applications

  • Smart Buildings & Home Automation
  • Smart Cities
  • Smart Factory


1.5 Sleep mode and working mode

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

Working Mode: In this mode, Sensor will work as NB-IoT Sensor to Join NB-IoT 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

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Behavior on ACTFunctionAction
Pressing ACT between 1s < time < 3sSend an uplink

If sensor has already attached to NB-IoT network, sensor will send an uplink packet, blue led will blink once.
Meanwhile, BLE module will be active and user can connect via BLE to configure device.

Pressing ACT for more than 3sActive Device

Green led will fast blink 5 times, device will enter OTA mode for 3 seconds. And then start to  attach NB-IoT network.
Green led will solidly turn on for 5 seconds after joined in network.
Once sensor is active, BLE module will be active and user can connect via BLE to configure device, no matter if device attach NB-IoT network or not.

Fast press ACT 5 times.Deactivate DeviceRed led will solid on for 5 seconds. Means device is in Deep Sleep Mode.

Note: When the device is executing a program, the buttons may become invalid. It is best to press the buttons after the device has completed the program execution.

1.7 BLE connection

WL03A-NB support BLE remote configure and firmware update.

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 , Switch & SIM Direction

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1.8.1 Jumper JP2

Power on Device when put this jumper.

1.8.2 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

1.8.3 Reset Button

Press to reboot the device.

1.8.4 SIM Card Direction

See this link. How to insert SIM Card.

1.9 Mechanical

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1.10 Installation

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2. Use WL03A-NB to communicate with IoT Server

2.1 Send data to IoT server via NB-IoT network

The WL03A-NB is equipped with a NB-IoT module, the pre-loaded firmware in WL03A-NB will get environment data from sensors and send the value to local NB-IoT network via the NB-IoT module.  The NB-IoT network will forward this value to IoT server via the protocol defined by WL03A-NB.

Below shows the network structure:

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There are two version: -GE and -1D version of WL03A-NB.

GE Version: This version doesn't include SIM card or point to any IoT server. User needs to use AT Commands to configure below two steps to set WL03A-NB send data to IoT server.

  • Install NB-IoT SIM card and configure APN. See instruction of Attach Network.

Below shows result of different server as a glance.

ServersDash BoardComments


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General UDPRaw Payload. Need Developer to design Dash Board 
General MQTTRaw Payload. Need Developer to design Dash Board 


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1D Version: This version has 1NCE SIM card pre-installed and configure to send value to DataCake. User Just need to select the sensor type in DataCake and Activate WL03A-NB and user will be able to see data in DataCake. See here for DataCake Config Instruction.

2.2 ​Payload Types

To meet different server requirement, WL03A-NB supports different payload type.


User can specify the payload type when choose the connection protocol. Example:

AT+PRO=2,0             // Use UDP Connection & hex Payload

AT+PRO=2,5            // Use UDP Connection & Json Payload

AT+PRO=3,0             // Use MQTT Connection & Json Payload

AT+PRO=3,1            // Use MQTT Connection & ThingSpeak

AT+PRO=3,3             // Use MQTT Connection & ThingsBoard

AT+PRO=3,5            // Use MQTT Connection & Json Payload

AT+PRO=4,0            // Use TDP Connection & hex Payload

AT+PRO=4,5            // Use TDP Connection & Json Payload

2.2.1 General Json Format(Type=5)

This is the General Json Format. As below:

{"IMEI":"866207058378443","Model":"WL03A-NB","status":0,"leak_times":6,"last_leak_time":4,"battery":3.431,"signal":22,"1":{0,1581823333,4,2023/11/16 08:32:47},"2":{0,1581823333,4,2023/11/16 08:17:47},"3":{0,1682486617,4,2023/11/16 08:02:47},"4":{0,1699263831,0,2023/11/16 07:47:46},"5":{0,1699263831,0,2023/11/16 07:32:46},"6":{0,1699263831,0,2023/11/16 07:17:46},"7":{0,1699263831,0,2023/11/16 07:02:46},"8":{0,0,0,1970/01/01 00:00:11}}

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Notice, from above payload:

  • Leak_status, Leak_times, Last_leak_time, Battery & Signal are the value at uplink time.
  • Json entry 1 ~ 8 are the last 1 ~ 8 sampling data as specify by AT+NOUD=8  Command. Each entry includes (from left to right): Leak_times, Last_leak_time & Sampling time.


2.2.2 HEX format Payload(Type=0)

This is the HEX Format. As below:


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These bytes include the hardware and software version.

Higher byte: Specify Sensor Model: 0x14 for WL03A-NB

Lower byte: Specify the software version: 0x64=100, means firmware version 1.0.0

BAT (Battery Info):

Ex1: 0x0dda = 3546mV

Signal Strength:

NB-IoT Network signal Strength.

Ex1: 0x15 = 21

0        -113dBm or less

1        -111dBm

2...30 -109dBm... -53dBm

31      -51dBm or greater

99      Not known or not detectable


See 2.9 Alarm Base on Timeout.

Count mod:Default=0

0 --> Uplink total leak times since factory

1 --> Uplink total leak times since last uplink. 


0 --> It is not an uplink sent when TDC or Leakalarm.

1 -->It is an uplink sent when TDC or Leakalarm.

Leak status:

This byte is 1 when the leak sensor is leak and 0 when it is no leak. 

Leak times:

Total pulse/counting base on leak.

Range (3 Bytes) : 0x000000 ~ 0xFFFFFF . Max: 16777215

Last leak duration:

Leak sensor last leak duration.

Unit: sec.

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Unit Timestamp Example: 650abc40(H) = 1695202368(D)

Put the decimal value into this link( to get the time.

2.2.3 ThingsBoard Payload(Type=3)

Type3 payload special design for ThingsBoard, it will also configure other default server to ThingsBoard.

        "IMEI": "866207058378443",
        "Model": "WL03A-NB",
        "status": 1,
        "leak_times": 20,
        "last_leak_time": 1,
        "battery": 3.401,
        "signal": 21

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2.2.4 ThingSpeak Payload(Type=1)

This payload meets ThingSpeak platform requirement. It includes only five fields. Form 1~5are:

Status, Leak_times, Last_leak_time, Battery & Signal. This payload type only valid for ThingsSpeak Platform.

As below:

field1=Leak_status value&field2=Leak_times value&field3=Last_leak_time value&field4=Battery value&field5=Singal value

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2.3 Test Uplink and Change Update Interval

By default, Sensor will send uplinks every 2 hours & AT+NOUD=8

User can use below commands to change the uplink interval.

AT+TDC=600        // Set Update Interval to 600s

User can also push the button for more than 1 seconds to activate an uplink.

Notice: The AT+NOUD feature is upgraded to Clock Logging, please refer Clock Logging Feature

Note: When WL03A-NB is reset and AT+COUNTMOD=0, the leak times will be read from the latest recorded data as the initial value.

To save battery life, WL03A-NB will sample Water Flow data every 15 minutes and send one uplink every 2 hours. So each uplink it will include 8 stored data + 1 real-time data. They are defined by:

  • AT+TR=900        // The unit is seconds, and the default is to record data once every 900 seconds (15 minutes, the minimum can be set to 180 seconds)
  • AT+NOUD=8     //  The device uploads 8 sets of recorded data by default. Up to 32 sets of record data can be uploaded.

The diagram below explains the relationship between TR, NOUD, and TDC more clearly:

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2.5 Enable / Disable Alarm

Feature: Enable/Disable Alarm for open/close event. Default value 0.

AT Command:

Command ExampleFunctionResponse
AT+DISALARM=1End node will only send packet in TDC time.OK
AT+DISALARM=0End node will send packet in TDC time or status change for water leak sensorOK


2.6 Alarm Base on Timeout

WL03A-NB can monitor the timeout for a status change, this feature can be used to monitor some events such as door opening too long etc.

User configure this feature by using:

AT Command to configure:

  • AT+TTRIG=1,30   --> When status change from no leak to leak, and device keep in leak status for more than 30 seconds. WL03A-NB will send an uplink packet, the Alarm bit (the second bit of 1st byte of payload) on this uplink packet is set to 1.
  • AT+TTRIG=0,30   --> When status change from leak to no leak, and device keep in no leak status for more than 30 seconds. WL03A-NB will send an uplink packet, the Alarm bit (the second bit of 1st byte of payload) on this uplink packet is set to 1.
  • AT+TTRIG=0,0     -->  Default Value, disable timeout Alarm.


2.7 The working mode of the total water leakage event

Feature:Counting mode 

AT Command to configure:

  • AT+COUNTMOD=0 --> Default Value, Total leak events since factory.
  • AT+COUNTMOD=1 --> Total leak events since last TDC uplink.


2.8 Regularly update a uplink when water leaks

Feature: The interval between each uplink delivery when there is water leakage.

AT Command to configure:

  • AT+LEAKALARM=10 --> Default Value, A periodically update at every 10 minutes when in water leak.
  • AT+LEAKALARM=0   --> Disable a periodically update when in water leak.


2.9 Delay time for state changes to take effectEdit

Feature: Sensitivity settings for water leak detection

AT Command to configure:

  • AT+DETEDELAY=50 --> Default Value, Set state change, valid signal is 50ms.
  • AT+DETEDELAY=0   --> Disable valid signal detection.


2.10 Clear the leak count and the duration of the last leak

Feature: Clear last duration and count values.

AT Command:

Command ExampleFunctionResponse
AT+CLRCclear the leak count and the duration of the last leak.OK


2.11 Set the count value of the number of leaks

Feature: This setting can clear the pulse count to 0 or set it to a custom value.

AT Command:

Command ExampleFunctionResponse
AT+ SETCNT =0Clear the leak count value to 0.OK
AT+SETCNT=100Set the leak count value to 100OK


2.12 Clock logging (Since firmware version v1.0.2)

Sometimes when we deploy lots of end nodes in field. We want all sensors sample data at the same time, and upload these data together for analyze. In such case, we can use clock loging feature.

We can use this command to set the start time of data recording and the time interval to meet the requirements of the specific collection time of data.

  • AT Command: AT+CLOCKLOG=a,b,c,d

a: 0: Disable Clock logging.   1: Enable Clock Logging

b: Specify First sampling start second: range (0 ~ 3599, 65535)         // Note: If parameter b is set to 65535, the log period starts after the node accesses the network and sends packets.

c: Specify the sampling interval: range (0 ~ 255 minutes)

d: How many entries should be uplink on every TDC (max 32)




After the node sends the first packet, data is recorded to the memory at intervals of 1 minute. For each TDC uplink, the uplink load will include: battery information + the last 5 memory records (payload + timestamp).


Note: Users need to synchronize the server time before configuring this command. If the server time is not synchronized before this command is configured, the command takes effect only after the node is reset.

2.13 Example Query saved historical records

  • AT Command: AT+CDP

This command can be used to search the saved history, recording up to 32 groups of data, each group of historical data contains a maximum of 100 bytes.


2.14 Uplink log query

  • AT Command: AT+GETLOG

This command can be used to query upstream logs of data packets.


2.15 Scheduled domain name resolution

This command is used to set up scheduled domain name resolution.

AT command:

  • AT+DNSTIMER=XX   // Unit: hour

After setting this command, domain name resolution will be performed regularly.

3. Configure WL03A-NB

3.1 Configure Methods

WL03A-NB supports below configure method:


3.2 AT Commands Set

AT+<CMD>?           : Help on <CMD>

AT+<CMD>                      : Run <CMD>

AT+<CMD>=<value>      : Set the value

AT+<CMD>=?          : Get the value

General Commands       

AT                    : Attention        

AT?                  : Short Help      

ATZ                 : MCU Reset     

AT+TDC          : Application Data Transmission Interval

AT+CFG          : Print all configurations

AT+CFGMOD           : Working mode selection

AT+DEUI                  : Get or set the Device ID

AT+5VT           : Set extend the time of 5V power   

AT+CLRC     : Clear the leak count and the duration of the last leak

AT+SETCNT     : Get or set the count at present

AT+DISALARM     : Enable/Disable Alarm for door open/close or water leak event

AT+LEAKALARM     : Get or Set the alarm interval for water leakage

AT+DETEDELAY      : Get or Set the detection delay of pin

AT+COUNTMOD      : Get or Set the count mode of water leakage

AT+TTRIG        : Get or Set Alarm Base on Timeout(PA8)

AT+PRO          : Choose agreement

AT+RXDL        : Extend the sending and receiving time

AT+DNSCFG   : Get or Set DNS Server

AT+GETSENSORVALUE   : Returns the current sensor measurement

AT+NOUD  : Get or Set the number of data to be uploaded

AT+CDP     : Read or Clear cached data

AT+SERVADDR :   Server Address

MQTT Management

AT+CLIENT               : Get or Set MQTT client

AT+UNAME              : Get or Set MQTT Username

AT+PWD                  : Get or Set MQTT password

AT+PUBTOPIC          : Get or Set MQTT publish topic

AT+SUBTOPIC          : Get or Set MQTT subscription topic


AT+FDR              : Factory Data Reset

AT+PWORD        : Serial Access Password

AT+LDATA           : Get the last upload data

AT+CDP               : Read or Clear cached data

4. Battery & Power Consumption

WL03A-NB use ER26500 + SPC1520 battery pack. See below link for detail information about the battery info and how to replace.

Battery Info & Power Consumption Analyze .

5. Firmware update

User can change device firmware to::

  • Update with new features.
  • Fix bugs. 

Firmware and changelog can be downloaded from : Firmware download link

Methods to Update Firmware:

  • (Recommended way) OTA firmware update via BLE: Instruction.


6. FAQ

6.1 How can I access t BC660K-GL AT Commands?

User can access to BC660K-GL directly and send AT Commands.

See BC660K-GL AT Command set

6.2 How to configure the device through the MQTT subscription function?

Subscription content: {AT COMMAND}


Setting AT+5VT=500 through Node-RED requires MQTT to send the content {AT+5VT=500}.

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The serial port displays:

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7. Order Info

Part Number: WL03A-NB-XX


  • GE: General version ( Exclude SIM card)
  • 1D: with 1NCE* 10 years 500MB SIM card and Pre-configure to DataCake server

1NCE SIM Card NB-IoT network coverage: Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Finland, Germany, Great Britain, Greece, Hungary, Ireland, Italy, Latvia, Malta, Netherlands, Norway, Puerto Rico, Russia, Slovak , Republic, Slovenia, Spain, Sweden, Switzerland, Taiwan, USA, US Virgin Islands

Notice: WL03A-NB includes a one meter water leak cable, If user want to extend the lenght, please choose Water Leak Cable DR-WLN-XX.

Water Leak Cable Part Number: DR-WLN-XX


  • 1M : 1 meter water leak cable
  • 5M : 5 meters water leak cable
  • 10M: 10 meters water leak cable


8. ​Packing Info

Package Includes:

  • 1 x WL03A-NB NB-IoT None-Position Rope Type Water Leak Controller 
  • 1 x 1m water lead cable
  • 1 x termination end

Dimension and weight:

  • Device Size: 13.0 x 5 x 4.5 cm
  • Device Weight: 150g
  • Package Size / pcs : 14.0 x 8x 5 cm
  • Weight / pcs : 180g


9. 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
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