Table of Contents:

• 1. Introduction
  • 1.1 What is NB-IoT Soil Moisture & EC 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 , Switch & SIM Direction
    • 1.8.1 Jumper JP2
    • 1.8.2 BOOT MODE / SW1
    • 1.8.3 Reset Button
    • 1.8.4 SIM Card Direction
  • 1.9 Mechanical
  • 1.10 Installation in Soil
• 2. Use SE02-NB to communicate with IoT Server
  • 2.1 Send data to IoT server via NB-IoT network
  • 2.2 ​Payload Types
    • 2.2.1 General Json Format(Type=5)
    • 2.2.2 HEX format Payload(Type=0)
    • 2.2.3 ThingsBoard Payload(Type=3)
    • 2.2.4 ThingSpeak Payload(Type=1)
  • 2.3 Test Uplink and Change Update Interval
  • 2.4 Trggier an uplink by external interrupt
  • 2.5 Clock logging (Since firmware version v1.2.1)
  • 2.6 Example Query saved historical records
  • 2.7 Uplink log query
  • 2.8 Scheduled domain name resolution
  • 2.9 Set the QoS level
  • 2.10 Set the downlink debugging mode(Since firmware v1.1.0)
  • 2.11 Domain name resolution settings(Since firmware v1.1.0)
• 3. Configure SE02-NB
  • 3.1 Configure Methods
  • 3.2  Serial Access Password
  • 3.3 AT Commands Set
• 4. Battery & Power Consumption
• 5. Firmware update
• 6. FAQ
  • 6.1 How can I access t BC660K-GL AT Commands?
  • 6.2  ​Can I calibrate SE02-NB to different soil types?
  • 6.3 How to configure the certificate?
• 7. Order Info
• 8. ​Packing Info
• 9. Support

1. Introduction

1.1 What is NB-IoT Soil Moisture & EC Sensor

The Dragino SE02-NB is a NB-IoT Soil Moisture & EC Sensor for IoT of Agriculture which has 2 sensor probes. It is designed to measure the soil moisture of saline-alkali soil and loamy soil. The soil sensor uses FDR method to calculate the soil moisture with the compensation from soil temperature and conductivity. It also has been calibrated in factory for Mineral soil type.

It detects Soil Moisture, Soil Temperature and Soil Conductivity, and uploads the value via wireless to NB-IoT IoT Server.

SE02-NB supports different uplink methods including MQTT, MQTTs, UDP & TCP for different application requirement, and support uplinks to various IoT Servers.

SE02-NB supports BLE configure and OTA update which make user easy to use.

SE02-NB is powered by 8500mAh Li-SOCI2 battery, it is designed for long-term use up to several years.

SE02-NB has optional built-in SIM card and default IoT server connection version. Which makes it works with simple configuration.

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
• External 2× sensor probes, probe length: 2.5m
• Monitor Soil Moisture
• Monitor Soil Temperature
• Monitor Soil Conductivity
• 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

Soil Moisture:

• Range: 0-100.00 V/V %
• Resolution: 0.01 V/V %
• Accuracy: ±3% (0-53%)V/V %, ±5% (>53%) V/V %
• Measure Method: FDR , with temperature &EC compensate 

Soil Temperature

• Range: -40.00°C ~ 85.00°C
• Resolution: 0.01°C
• Accuracy: -10°C ~ 50°C:<0.3°C, All other: <0.6°C
• Measure Method: RTD, and calibrate

Soil Conductivity

• Range: 0-20000 uS/cm(25°C)(0-20.0EC)
• Resolution: 1 uS/cm
• Accuracy: 2%FS
• Measure Method: Conductivity, with temperature compensate

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

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

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

1.4 Applications

• Smart Agriculture

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

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

SE02-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

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

Main Device Dimension:

Probe Dimension:

1.10 Installation in Soil

Measurement the soil surface

 ​

2. Use SE02-NB to communicate with IoT Server

2.1 Send data to IoT server via NB-IoT network

The SE02-NB is equipped with a NB-IoT module, the pre-loaded firmware in SE02-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 SE02-NB.

Below shows the network structure:

There are two version: -GE and -1D version of SE02-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 SE02-NB send data to IoT server.

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

• Set up sensor to point to IoT Server. See instruction of Configure to Connect Different Servers.  

Below shows result of different server as a glance.

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 SE02-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, SE02-NB supports different payload type.

Includes:

• General JSON format payload. (Type=5)

• HEX format Payload. (Type=0)

• ThingSpeak Format. (Type=1)

• ThingsBoard Format. (Type=3)

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=3,5            // Use MQTT Connection & Json Payload

2.2.1 General Json Format(Type=5)

This is the General Json Format. As below:

{"IMEI":"863663062798914","IMSI":"460083513507314","Model":"SE02-NB","tem":21.0,"hum":19.4,"ec":7465,"tem2":20.8,"hum2":21.2,"ec2":8147,"interrupt":0,"interrupt_level":0,"battery":3.27,"signal":17,"time":"2024/11/23 01:06:52","1":[0.0,0.0,0,0.0,0.0,0,"2024/11/23 00:53:30"],"2":[0.0,0.0,0,0.0,0.0,0,"2024/11/23 00:38:30"],"3":[0.0,0.0,0,0.0,0.0,0,"2024/11/23 00:23:30"],"4":[0.0,0.0,0,0.0,0.0,0,"2024/11/23 00:08:30"],"5":[0.0,0.0,0,0.0,0.0,0,"2024/11/22 23:53:30"],"6":[0.0,0.0,0,0.0,0.0,0,"2024/11/22 23:38:30"],"7":[0.0,0.0,0,0.0,0.0,0,"2024/11/22 23:23:30"],"8":[0.0,0.0,0,0.0,0.0,0,"2024/11/22 23:08:30"]}

Notice, from above payload:

• Temperature, Humidity, Soil conductivity, Temperature 2,  Humidity 2, Soil conductivity 2, Interrupt, Interrupt_level, Battery, Signal & time are the value at uplink time.

• Json entry 1 ~ 8 are the last 1 ~ 8 sampling data as specify by AT+CLOCKLOG=1,65535,15,8 Command. Each entry includes (from left to right): Soil Temperature, Soil Moisture, Soil Conductivity(EC), Soil Temperature 2, Soil Moisture 2, Soil Conductivity 2(EC) & Sampling time. 

2.2.2 HEX format Payload(Type=0)

This is the HEX Format. As below:

f863663062798914f460083513507314366e0cd811010000079f08311da7084d081e1f9067412b770000000000000000000000006741278a000000000000000000000000674124060000000000000000000000006741208200000000000000000000000067411cfe0000000000000000000000006741197a000000000000000000000000674115f60000000000000000000000006741127200000000000000000000000067410eee

If we use the MQTT client to subscribe to this MQTT topic, we can see the following information when the NB sensor uplink data.

Version:

These bytes include the hardware and software version.

Higher byte: Specify Sensor Model: 0x36 for SE02-NB

Lower byte: Specify the software version: 0x82=130, means firmware version 1.3.0

BAT (Battery Info):

Ex1: 0x0CD1 = 3281mV

Signal Strength:

NB-IoT Network signal Strength.

Ex1: 0x16 = 22

0        -113dBm or less

1        -111dBm

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

31      -51dBm or greater

99      Not known or not detectable

Soil Moisture 

Soil Temperature 

Soil Conductivity (EC) 

TimeStamp:   

Unit TimeStamp Example: 665eb834(H) = 1717483572(D)

Put the decimal value into this link(https://www.epochconverter.com)) 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.

 {
    "topic": "2276492",
    "payload": {
        "IMEI": "863663062798930",
        "Model": "SE02-NB",
        "tem": 26.0,
        "hum": 47.6,
        "ec": 8806,
        "tem2": 26.0,
        "hum2": 55.0,
        "ec2": 8973,
        "interrupt": 0,
        "interrupt_level": 0,
        "battery": 3.29,
        "signal": 22,
        "1": [26.0, 47.6, 8915, 26.0, 55.0, 8918, "2024/06/04 07:08:13"],
        "2": [26.0, 47.6, 8933, 26.0, 55.0, 9028, "2024/06/04 07:06:13"],
        "3": [26.0, 47.6, 8907, 26.0, 55.1, 8907, "2024/06/04 07:04:13"],
        "4": [26.0, 47.6, 8845, 26.0, 55.0, 9044, "2024/06/04 07:02:13"],
        "5": [26.0, 47.6, 8917, 26.0, 55.1, 8985, "2024/06/04 07:00:13"],
        "6": [26.0, 47.5, 8883, 26.0, 55.0, 9041, "2024/06/04 06:58:13"],
        "7": [26.0, 47.6, 8965, 26.0, 55.0, 8952, "2024/06/04 06:56:13"],
        "8": [26.0, 47.6, 8844, 26.0, 55.0, 8994, "2024/06/04 06:54:13"]
    }
}

2.2.4 ThingSpeak Payload(Type=1)

This payload meets ThingSpeak platform requirement. It includes six fields. Form 1~8 are:

Temperature, Humidity, Conduct soil, Temperature 2, Humidity 2, Conduct soil 2, Battery & Signal. This payload type only valid for ThingsSpeak Platform.

As below:

field1=Temperature value&field2=Humidity value&field3=Conduct soil value&field4=Temperature 2 value&field5=Humidity 2 value&field6=Conduct soil 2 value&field7=Battery value&field8=Signal value

2.3 Test Uplink and Change Update Interval

By default, Sensor will send uplinks every 2 hours 

User can use below commands to change the uplink interval.

AT+TDC=7200        // Set Update Interval to 7200s

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

2.4 Trggier an uplink by external interrupt

SE02-NB has an external trigger interrupt function. Users can use the GPIO_EXIT pin to trigger the upload of data packets.

AT command:

• AT+INTMOD         // Set the trigger interrupt mode

• AT+INTMOD=0    // Disable Interrupt

• AT+INTMOD=1    // Trigger by rising and falling edge

• AT+INTMOD=2    // Trigger by falling edge

• AT+INTMOD=3    // Trigger by rising edge

2.5 Clock logging (Since firmware version v1.2.1)

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)

Note: To disable clock recording, set the following parameters: AT+CLOCKLOG=1,65535,0,0

Example:

AT+CLOCKLOG=1,65535,1,5

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.

• Downlink command: 0x0A

Format: Command Code (0x0A) followed by 5 bytes.

• Example 1: Downlink Payload: 0A01FFFF0F08             // Set SHT record time: AT+CLOCKLOG=1,65535,15,8
• Example 1: Downlink Payload: 0A0104B00F08             // Set SHT record time: AT+CLOCKLOG=1,1200,15,8

Note: When entering the downlink payload, there must be no Spaces between bytes.

2.6 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.

2.7 Uplink log query

• AT command: AT+GETLOG

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

2.8 Scheduled domain name resolution

This command is used to set up scheduled domain name resolution

AT command:

• AT+DNSTOMER=XX  // Unit: hour

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

2.9 Set the QoS level

This command is used to set the QoS level of MQTT.

AT command:

• AT+MQOS=xx   // 0~2

Downlink command: 0x07

Format: Command Code (0x07) followed by 1 byte.

Ex1: Downlink payload: 0x0700   //AT+MQOS=0

Ex2: Downlink payload: 0x0701   //AT+MQOS=1

2.10 Set the downlink debugging mode(Since firmware v1.1.0)

Feature: Set the conversion between the standard version and 1T version downlinks.

AT command: AT+DOWNTE

Example:

• AT+DOWNTE=0,1  //Set to standard version downlink, and enable downlink debugging.
• AT+DOWNTE=1,1  //Set to 1T version downlink, and enable downlink debugging.

Downlink Command:  

No downlink commands for feature

2.11 Domain name resolution settings(Since firmware v1.1.0)

Feature: Set dynamic domain name resolution IP.

AT command: AT+BKDNS

Example:

• AT+BKDNS=1,0        //Dynamic domain name resolution is disabled.
• AT+BKDNS=2,1        //The dynamic domain name resolution function is enabled and the automatic update time is set to 1 hour.
• AT+BKDNS=2,4,3.69.98.183,1883      //The dynamic domain name resolution function is enabled and the automatic update time is set to 4 hour, and manually set the ip address, if the domain name failed to resolve, it will directly use this ip to communicate. When the next domain name resolution is successful, it will be updated to the ip address of the successful resolution.

Downlink Command:  

No downlink commands for feature

3. Configure SE02-NB

3.1 Configure Methods

SE02-NB supports below configure method:

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

• AT Command via UART Connection : See UART Connection.

3.2  Serial Access Password

After the Bluetooth or UART connection is successful, use the Serial Access Password to enter the AT command window.

The label on the box of the node will print the initial password: AT+PIN=xxxxxx, and directly use the six-digit password to access the AT instruction window.

If you need to change the password, use AT+PWORD=xxxxxx (6 characters), NB nodes only support lowercase letters.

Note: After entering the command, you need to add a line break, and you can also set automatic line breaks in the Bluetooth tool or UART connection tool.

3.3 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+INTMOD            : Set the trigger interrupt mode

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

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

Information           

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

SE02-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.

• Update through UART TTL interface : 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  ​Can I calibrate SE02-NB to different soil types?

6.3 How to configure the certificate?

User can can refer to this description to configure the certificate.

7. Order Info

Part Number: SE02-NB-XX

XX: 

• GE: General version ( Exclude SIM card)

• 1T: with 1NCE* 10 years 500MB SIM card and Pre-configure to ThingsEye server

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

8. ​Packing Info

Package Includes:

• SE02-NB NB-IoT Soil Moisture & EC Sensor x 1

• External antenna x 1

Dimension and weight:

• Device Size: cm

• Device Weight: g

• Package Size / pcs : cm

• Weight / pcs : g

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 Support@dragino.cc.