Table of Contents:

• 1. Introduction
  • 1.1 What is LHT65N LoRaWAN Temperature & Humidity Sensor
  • 1.2 Features
  • 1.3 Specification
• 2. Connect LHT65N to IoT Server
  • 2.1 How does LHT65N work?
  • 2.2 How to Activate LHT65N?
  • 2.3 Example to join LoRaWAN network
    • 2.3.1 Step 1: Create Device n TTN
    • 2.3.2 Step 2: Activate LHT65N by pressing the ACT button for more than 5 seconds.
  • 2.4 Uplink Payload (Fport=2)
    • 2.4.1 Decoder in TTN V3
    • 2.4.2 BAT-Battery Info
    • 2.4.3 Built-in Temperature
    • 2.4.4 Built-in Humidity
    • 2.4.5 Ext #
    • 2.4.6 Ext value
      • 2.4.6.1 Ext=1, E3 Temperature Sensor
      • 2.4.6.2 Ext=9, E3 sensor with Unix Timestamp
      • 2.4.6.3 Ext=6, ADC Sensor(use with E2 Cable)
      • 2.4.6.4 Ext=2 TMP117 Sensor(Since Firmware v1.3)
      • 2.4.6.5 Ext=11 SHT31 Sensor (Since Firmware v1.4.1)
      • 2.4.6.6 Ext=4 Interrupt Mode(Since Firmware v1.3)
      • 2.4.6.7 Ext=8 Counting Mode(Since Firmware v1.3)
      • 2.4.6.8 Ext=10, E2 sensor (TMP117)with Unix Timestamp(Since firmware V1.3.2)
  • 2.5 Show data on Datacake
  • 2.6 Datalog Feature
    • 2.6.1 Ways to get datalog via LoRaWAN
    • 2.6.2 Unix TimeStamp
    • 2.6.3 Set Device Time
    • 2.6.4 Poll sensor value
    • 2.6.5 Datalog Uplink payload
  • 2.7 Alarm Mode & Feature "Multi sampling, one uplink"
    • 2.7.1 ALARM MODE ( Since v1.3.1 firmware)
    • 2.7.2 ALARM MODE ( Before v1.3.1 firmware)
  • 2.8 LED Indicator
  • 2.9 installation
• 3. Sensors and Accessories
  • 3.1 E2 Extension Cable
  • 3.2 E3 Temperature Probe
  • 3.3 E31F Temperature Probe
  • 3.4 NE117 Temperature Probe (Model: LHT65N-NE117)
  • 3.5 Dry Contact Probe (Model: LHT65N-DC)
  • 3.6 Door Sensor (Model: LHT65N-DS)
  • 3.6 NIS Certificate Probe (Model: LHT65N-NIS)
• 4. Configure LHT65N via AT command or LoRaWAN downlink
  • 4.1 Set Transmit Interval Time
  • 4.2 Set External Sensor Mode
  • 4.3 Enable/Disable uplink DS18B20 Temperature probe ID
  • 4.4 Set Password
  • 4.5 Quit AT Command
  • 4.6 Set to sleep mode
  • 4.7 Set system time
  • 4.8 Set Time Sync Mode
  • 4.9 Set Time Sync Interval
  • 4.10 Get data
  • 4.11 Print data entries base on page
  • 4.12 Print last few data entries
  • 4.13 Clear Flash Record
  • 4.14 Auto Send None-ACK messages
  • 4.15 Modified WMOD command for external sensor TMP117 or DS18B20 temperature alarm(Since firmware 1.3.0)
  • 4.16 Get Firmware Version Info(Since V1.4.0)
• 5. Battery & How to replace
  • 5.1 Battery Type
  • 5.2 Replace Battery
  • 5.3 Battery Life Analyze
• 6. FAQ
  • 6.1 How to connect to LHT65N UART interface?
  • 6.2 How to use AT Commands?
  • 6.3 How to use Downlink commands?
  • 6.4 How to change the uplink interval?
  • 6.5 How to upgrade firmware?
    • 6.5.1 Update firmware (Assume device already have bootloader)
    • 6.5.2 Update firmware (Assume device doesn't have bootloader)
  • 6.6 Why can't I see the datalog information
  • 6.7 How can i read sensor data without LoRaWAN? For Calibration Purpose
• 7. Order Info
• 8. Packing Info
• 9. Reference material
• 10. FCC Warning

1. Introduction

1.1 What is LHT65N LoRaWAN Temperature & Humidity Sensor

1.2 Features

• LoRaWAN v1.0.3 Class A protocol
• Frequency Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915
• AT Commands to change parameters
• Remote configure parameters via LoRaWAN Downlink
• Firmware upgradeable via program port
• Built-in 2400mAh battery for up to 10 years of use.
• Built-in Temperature & Humidity sensor
• Optional External Sensors
• Tri-color LED to indicate working status
• Datalog feature (Max 3328 records)

1.3 Specification

Built-in Temperature Sensor:

• Resolution: 0.01 °C
• Accuracy Tolerance : Typ ±0.3 °C
• Long Term Drift: < 0.02 °C/yr
• Operating Range: -40 ~ 85 °C

Built-in Humidity Sensor:

• Resolution: 0.04 %RH
• Accuracy Tolerance : Typ ±3 %RH
• Long Term Drift: < 0.25 RH/yr
• Operating Range: 0 ~ 96 %RH

External Temperature Sensor:

• Resolution: 0.0625 °C
• ±0.5°C accuracy from -10°C to +85°C
• ±2°C accuracy from -55°C to +125°C
• Operating Range: -55 °C ~ 125 °C

2. Connect LHT65N to IoT Server

2.1 How does LHT65N work?

2.2 How to Activate LHT65N?

• Deep Sleep Mode: LHT65N doesn't have any LoRaWAN activation. This mode is used for storage and shipping to save battery life.

• Working Mode:     In this mode, LHT65N works as LoRaWAN Sensor mode to Join LoRaWAN network and send out the sensor data to the server. Between each sampling/tx/rx periodically, LHT65N will be in STOP mode (IDLE mode), in STOP mode, LHT65N has the same power consumption as Deep Sleep mode.  

2.3 Example to join LoRaWAN network

This section shows an example of how to join the TTN V3 LoRaWAN IoT server. Use with other LoRaWAN IoT servers is of a similar procedure.

2.3.1 Step 1: Create Device n TTN

User can enter these keys in the LoRaWAN Server portal. Below is TTN V3 screenshot:

Add APP EUI in the application.

1. Create application

2. Register end device 

Note: LHT65N use same payload as LHT65.

Input APP EUI,  APP KEY and DEV EUI:

2.3.2 Step 2: Activate LHT65N by pressing the ACT button for more than 5 seconds.

2.4 Uplink Payload (Fport=2)

• The First 6 bytes: has fix meanings for every LHT65N.

• The 7th byte (EXT #): defines the external sensor model. 

• The 8^th ~ 11^th byte: the value for external sensor value. The definition is based on external sensor type. (If EXT=0, there won't be these four bytes.)

2.4.1 Decoder in TTN V3

When the uplink payload arrives TTNv3, it shows HEX format and not friendly to read. We can add LHT65N decoder in TTNv3 for friendly reading.

Below is the position to put the decoder and LHT65N decoder can be download from here: https://github.com/dragino/dragino-end-node-decoder

2.4.2 BAT-Battery Info

These two bytes of BAT include the battery state and the actually voltage.

(b)stands for binary

Check the battery voltage for LHT65N.

• BAT status=(0Xcba4>>14)&0xFF=11 (BIN) ，very good

• Battery Voltage =0xCBA4&0x3FFF=0x0BA4=2980mV

2.4.3 Built-in Temperature

• Temperature:  0x0ABB/100=27.47℃

• Temperature:  (0xF5C6-65536)/100=-26.18℃

2.4.4 Built-in Humidity

• Humidity:    0x025C/10=60.4%

2.4.5 Ext #

Bytes for External Sensor:

2.4.6 Ext value

2.4.6.1 Ext=1, E3 Temperature Sensor

• DS18B20 temp=0x0ADD/100=27.81℃

The last 2 bytes of data are meaningless

• External temperature= (0xF54F-65536)/100=-27.37℃

F54F :  (F54F & 8000 == 1) , temp = (F54F - 65536)/100 = 27.37℃

（0105 & 8000：Judge whether the highest bit is 1, when the highest bit is 1, it is negative）

The last 2 bytes of data are meaningless

If the external sensor is 0x01, and there is no external temperature connected. The temperature will be set to 7FFF which is 327.67℃

2.4.6.2 Ext=9, E3 sensor with Unix Timestamp

• Battery status & Built-in Humidity

• Status & Ext Byte

• Poll Message Flag:    1: This message is a poll message reply, 0: means this is a normal uplink.
• Sync time OK:            1: Set time ok，0: N/A. After time SYNC request is sent, LHT65N will set this bit to 0 until got the time stamp from the application server.
• Unix Time Request:  1: Request server downlink Unix time, 0 : N/A. In this mode, LHT65N will set this bit to 1 every 10 days to request a time SYNC. (AT+SYNCMOD to set this)

2.4.6.3 Ext=6, ADC Sensor(use with E2 Cable)

In this mode, user can connect external ADC sensor to check ADC value. The 3V3_OUT can

be used to power the external ADC sensor; user can control the power on time for this

sensor by setting:

AT+EXT=6,timeout          Time to power this sensor, from 0 ~ 65535ms

For example:

AT+EXT=6,1000 will power this sensor for 1000ms before sampling the ADC value.

Or use downlink command A2 to set the same.

The measuring range of the node is only about 0.1V to 1.1V The voltage resolution is about 0.24mv.

When the measured output voltage of the sensor is not within the range of 0.1V and 1.1V, the output voltage terminal of the sensor shall be divided The example in the following figure is to reduce the output voltage of the sensor by three times If it is necessary to reduce more times, calculate according to the formula in the figure and connect the corresponding resistance in series.

When ADC_IN1 pin is connected to GND or suspended, ADC value is 0

When the voltage collected by ADC_IN1 is less than the minimum range, the minimum range will be used as the output; Similarly, when the collected voltage is greater than the maximum range, the maximum range will be used as the output.

1) The minimum range is about 0.1V. Each chip has internal calibration, so this value is close to 0.1V

2) The maximum range is about 1.1V. Each chip has internal calibration, so this value is close to 1.1v

3) Within range

2.4.6.4 Ext=2 TMP117 Sensor(Since Firmware v1.3)

Ext=2,Temperature Sensor(TMP117):

Interrupt Mode and Counting Mode:

The external cable NE2 can be use for MOD4 and MOD8

2.4.6.5 Ext=11 SHT31 Sensor (Since Firmware v1.4.1)

Ext=11,Temperature & Humidity Sensor(SHT31):

2.4.6.6 Ext=4 Interrupt Mode(Since Firmware v1.3)

Note: In this mode, 3.3v output will be always ON. LHT65N will send an uplink when there is a trigger.

Interrupt Mode can be used to connect to external interrupt sensors such as:

Case 1: Door Sensor. 3.3v Out for such sensor is just to detect Open/Close.

 In Open State, the power consumption is the same as if there is no probe

 In Close state, the power consumption will be 3uA higher than normal.

Ext=4,Interrupt Sensor：

Trigger by falling edge:

Trigger by raising edge:

2.4.6.7 Ext=8 Counting Mode(Since Firmware v1.3)

Note: In this mode, 3.3v output will be always ON. LHT65N will count for every interrupt and uplink periodically.

Case 1:  Low power consumption Flow Sensor, such flow sensor has pulse output and the power consumption in uA level and can be powered by LHT65N. 

Case 2:  Normal Flow Sensor: Such flow sensor has higher power consumption and is not suitable to be powered by LHT65N. It is powered by external power and output <3.3v pulse

Ext=8, Counting Sensor ( 4 bytes)：

A2 downlink Command：

A2 02:             Same as AT+EXT=2   (AT+EXT= second byte)

A2 06 01 F4:   Same as AT+EXT=6,500  (AT+EXT= second byte, third and fourth bytes)

A2 04 02:        Same as AT+EXT=4,2  (AT+EXT= second byte, third byte)

A2 08 01 00:   Same as AT+EXT=8,0  (AT+EXT= second byte, fourth byte)

A2 08 02 00 00 00 3C:    Same as AT+ SETCNT=60  (AT+ SETCNT = 4th byte and 5th byte and 6th byte and 7th byte)

2.4.6.8 Ext=10, E2 sensor (TMP117)with Unix Timestamp(Since firmware V1.3.2)

• Battery status & Built-in Humidity

• Status & Ext Byte

• Poll Message Flag:    1: This message is a poll message reply, 0: means this is a normal uplink.
• Sync time OK:            1: Set time ok, 0: N/A. After time SYNC request is sent, LHT65N will set this bit to 0 until got the time stamp from the application server.
• Unix Time Request:  1: Request server downlink Unix time, 0 : N/A. In this mode, LHT65N will set this bit to 1 every 10 days to request a time SYNC. (AT+SYNCMOD to set this)

2.5 Show data on Datacake

Select default key as Access Key:

In Datacake console (https://datacake.co/) , add LHT65 device.

2.6 Datalog Feature

2.6.1 Ways to get datalog via LoRaWAN

There are two methods:

Method 1: IoT Server sends a downlink LoRaWAN command to poll the value for specified time range.

Method 2: Set PNACKMD=1, LHT65N will wait for ACK for every uplink, when there is no LoRaWAN network, LHT65N 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.

Note for method 2:

• a) LHT65N will do an ACK check for data records sending to make sure every data arrive server.
• b) LHT65N will send data in CONFIRMED Mode when PNACKMD=1, but LHT65N 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 LHT65N gets a ACK, LHT65N will consider there is a network connection and resend all NONE-ACK Message. 

Below is the typical case for the auto-update datalog feature (Set PNACKMD=1)

2.6.2 Unix TimeStamp

LHT65N 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

2.6.3 Set Device Time

2.6.4 Poll sensor value

User can poll sensor value based on timestamps from the server. Below is the downlink command.

Timestamp start and Timestamp end use Unix TimeStamp format as mentioned above. Devices will reply with all data log during this time period, use the uplink interval.

For example, downlink command 31 5FC5F350 5FC6 0160 05 

Is to check 2020/12/1 07:40:00 to 2020/12/1 08:40:00's data

Uplink Internal =5s, means LHT65N will send one packet every 5s. range 5~255s.

2.6.5 Datalog Uplink payload

The Datalog poll reply uplink will use below payload format.

Retrieval data payload:

Poll message flag & Ext:

No ACK Message:  1: This message means this payload is fromn Uplink Message which doesn't get ACK from the server before ( for PNACKMD=1 feature)

Poll Message Flag: 1: This message is a poll message reply.

• Poll Message Flag is set to 1.

• Each data entry is 11 bytes, to save airtime and battery, devices will send max bytes according to the current DR and Frequency bands.

For example, in 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 devise doesn't have any data in the polling time. Device will uplink 11 bytes of 0    

Example:

If LHT65N has below data inside Flash:

If user sends below downlink command:  3160065F9760066DA705

Where : Start time: 60065F97 = time 21/1/19 04:27:03

             Stop time: 60066DA7= time 21/1/19 05:27:03

LHT65N will uplink this payload.

7FFF089801464160065F97 7FFF 088E 014B 41 60066009 7FFF0885014E41600660667FFF0875015141600662BE7FFF086B015541600665167FFF08660155416006676E7FFF085F015A41600669C67FFF0857015D4160066C1E

Where the first 11 bytes is for the first entry:

7FFF089801464160065F97

Ext sensor data=0x7FFF/100=327.67

Temp=0x088E/100=22.00

Hum=0x014B/10=32.6

poll message flag & Ext=0x41,means reply data,Ext=1

Unix time is 0x60066009=1611030423s=21/1/19 04:27:03

2.7 Alarm Mode & Feature "Multi sampling, one uplink"

2.7.2 ALARM MODE ( Before v1.3.1 firmware)

Downlink Command: AAXXXXXXXXXXXXXX

Total bytes: 8 bytes

Example:AA0100010001003C

WMOD=01

CITEMP=0001

TEMPlow=0001

TEMPhigh=003C

2.8 LED Indicator

The LHT65 has a triple color LED which for easy showing different stage .

While user press ACT button, the LED will work as per LED status with ACT button.

In a normal working state:

• For each uplink, the BLUE LED or RED LED will blink once.
  BLUE LED when external sensor is connected.
• RED LED when external sensor is not connected
• For each success downlink, the PURPLE LED will blink once

2.9 installation

3. Sensors and Accessories

3.1 E2 Extension Cable

1m long breakout cable for LHT65N. Features:

• Use for AT Command, works for both LHT52/LHT65N

• Update firmware for LHT65N, works for both LHT52/LHT65N

• Supports ADC mode to monitor external ADC

• Supports Interrupt mode

• Exposed All pins from the LHT65N Type-C connector.

   

3.2 E3 Temperature Probe

Temperature sensor with 2 meters cable long

• Resolution: 0.0625 °C
• ±0.5°C accuracy from -10°C to +85°C
• ±2°C accuracy from -55°C to +125°C
• Operating Range: -40 ~ 125 °C
• Working voltage 2.35v ~ 5v

3.3 E31F Temperature Probe

Temperature sensor with 1 meters cable long

Built-in Temperature Sensor:

• Resolution: 0.01 °C
• Accuracy Tolerance : Typ ±0.3 °C
• Long Term Drift: < 0.02 °C/yr
• Operating Range: -40 ~ 80 °C

Built-in Humidity Sensor:

• Resolution: 0.04 % RH
• Accuracy Tolerance : Typ ±3 % RH
• Long Term Drift: < 0.02 °C/yr
• Operating Range: 0 ~ 96 % RH 

External Temperature Sensor :

• Resolution: 0.01 °C
• Accuracy Tolerance : Typical ±0.3 °C
• Long Term Drift: < 0.02 °C/yr
• Operating Range: -40 ~ 125 °C

External Humidity Sensor :

• Resolution: 0.04 % RH
• Accuracy Tolerance : Typ ±3 % RH
• Long Term Drift: < 0.02 °C/yr
• Operating Range: 0 ~ 96 % RH

3.4 NE117 Temperature Probe (Model: LHT65N-NE117)

External Temperature Sensor – NE117:
Equip with TMP117A temperature sensor. TMP117 IC is NIST traceability Sensor by TI.

• Silica gel cable
• ±0.1 °C (maximum) from –20 °C to 50 °C
• ±0.2 °C (maximum) from –40 °C to 100 °C
• ±0.3 °C (maximum) from –55 °C to 150 °C

3.5 Dry Contact Probe (Model: LHT65N-DC)

• Design for Pulse Counting(Ext=8), Alarm (Ext=4),Open/Close Detect (Ext=4)
• 3 wires: VCC/GND/INT
• Cable Lenght: 1 meter

LHT65-DC can be used to connect various types of external sensor. below.

User can refer this link for the instructions: LHT65-DC Connection Instruction.

3.6 Door Sensor (Model: LHT65N-DS)

• Aluminum Alloy Door Sensor
• Detect Distance: ~3cm
• Cable Lenght: 1 meter

Notice: When order LHT65N-DS, the device is by default set to: a) AT+EXT=4,1 ; b) Default Uplink Interval TDC is 12 hour.

3.6 NIS Certificate Probe (Model: LHT65N-NIS)

External Probe:

• Unique NIST Certi cate for each probe
• External NIST Traceable probe with unique ID

Notice: AT+PID=1 is by default enable, so LHT65N will also uplink the probe ID to platform.

4. Configure LHT65N via AT command or LoRaWAN downlink

• AT Command Connection: See FAQ.

• LoRaWAN Downlink instruction for different platforms: IoT LoRaWAN Server

• General Commands.

1. General system settings like: uplink interval.

2. LoRaWAN protocol & radio-related commands.

• Commands special design for LHT65N

4.1 Set Transmit Interval Time

Feature: Change LoRaWAN End Node Transmit Interval.

AT Command: AT+TDC

Downlink Command: 0x01

Format: Command Code (0x01) followed by 3 bytes time value.

If the downlink payload=0100003C, it means set the END Node's Transmit Interval to 0x00003C=60(S), while type code is 01.

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

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

4.2 Set External Sensor Mode

Feature: Change External Sensor Mode.

AT Command: AT+EXT

Downlink Command: 0xA2

Total bytes: 2 ~ 5 bytes

Example:

• 0xA201: Set external sensor type to E1

• 0xA209: Same as AT+EXT=9

• 0xA20702003c: Same as AT+SETCNT=60

4.3 Enable/Disable uplink DS18B20 Temperature probe ID

Feature: If PID is enabled, LHT65N will send the DS18B20 temperature probe ID on:

• First Packet after OTAA Join
• Every 24 hours since the first packet.

PID is default set to disable (0)

Notice: This feature only valid when EXT=1 or EXt=9

AT Command:

Downlink Command:

• 0xA800     --> AT+PID=0
• 0xA801     --> AT+PID=1

4.4 Set Password

Feature: Set device password, max 9 digits

AT Command: AT+PWORD

Downlink Command:

No downlink command for this feature.

4.5 Quit AT Command

Feature: Quit AT Command mode, so user needs to input password again before use AT Commands.

AT Command: AT+DISAT

Downlink Command:

No downlink command for this feature.

4.6 Set to sleep mode

Feature: Set device to sleep mode

• AT+Sleep=0  : Normal working mode, device will sleep and use lower power when there is no LoRa message
• AT+Sleep=1 :  Device is in deep sleep mode, no LoRa activation happen, used for storage or shipping.

AT Command: AT+SLEEP

Downlink Command:

• There is no downlink command to set to Sleep mode.

4.7 Set system time

Feature: Set system time, unix format. See here for format detail.

AT Command:

Downlink Command:

0x306007806000        //  Set timestamp to 0x(6007806000),Same as AT+TIMESTAMP=1611104352

4.8 Set Time Sync Mode

AT Command:

Downlink Command:

0x28 01             //  Same As AT+SYNCMOD=1
0x28 00             //  Same As AT+SYNCMOD=0

4.9 Set Time Sync Interval

Feature: Define System time sync interval. SYNCTDC default value: 10 days.

AT Command:

Downlink Command:

0x29 0A       // Same as AT+SYNCTDC=0x0A

4.10 Get data

Feature: Get the current sensor data.

AT Command:

• AT+GETSENSORVALUE=0      // The serial port gets the reading of the current sensor
• AT+GETSENSORVALUE=1      // The serial port gets the current sensor reading and uploads it.

4.11 Print data entries base on page

Feature: Print the sector data from start page to stop page (max is 416 pages).

AT Command: AT+PDTA

Downlink Command:

No downlink commands for feature

4.12 Print last few data entries

Feature: Print the last few data entries

AT Command: AT+PLDTA

Downlink Command:

No downlink commands for feature

4.13 Clear Flash Record

Feature: Clear flash storage for data log feature.

AT Command: AT+CLRDTA

Downlink Command: 0xA3

• Example: 0xA301        //  Same as AT+CLRDTA

4.14 Auto Send None-ACK messages

Feature: LHT65N will wait for ACK for each uplink, If LHT65N doesn't get ACK from the IoT server, it will consider the message doesn't arrive server and store it. LHT65N keeps sending messages in normal periodically. Once LHT65N gets ACK from a server, it will consider the network is ok and start to send the not-arrive message.

AT Command: AT+PNACKMD

The default factory setting is 0

Downlink Command: 0x34

• Example: 0x3401       //  Same as AT+PNACKMD=1

4.15 Modified WMOD command for external sensor TMP117 or DS18B20 temperature alarm(Since firmware 1.3.0)

Feature: Set internal and external temperature sensor alarms.

AT+WMOD=parameter1,parameter2,parameter3,parameter4

Parameter 1:  Alarm mode:

0): Cancel

1): Threshold alarm

2): Fluctuation alarm

3): Sampling multiple times and uplink together

 Parameter 2:  Sampling time. Unit: seconds, up to 255 seconds.

Note: When the collection time is less than 60 seconds and always exceeds the set alarm threshold, the sending interval will not be the collection time, but will be sent every 60 seconds.

 Parameter 3 and parameter 4:

1):  If Alarm Mode is set to 1: Parameter 3 and parameter 4 are valid, as before, they represent low temperature and high temperature.

Such as AT+WMOD=1,60,45,105, it means high and low temperature alarm.

2):  If Alarm Mode is set to 2: Parameter 3 is valid, which represents the difference between the currently collected temperature and the last uploaded temperature.

Such as AT+WMOD=2,10,2,it means that it is a fluctuation alarm.

If the difference between the current collected temperature and the last Uplin is ±2 degrees, the alarm will be issued.

3): If Alarm Mode is set to 3:

• parameter1: Set Working Mode to Mode 3
• parameter2: Set the temperature sampling mode to 1(1:DS18B20;2:TMP117;3: Internal GXHT30).
• parameter3: Sampling Interval is 60s.
• parameter4: When there is 20 sampling dats, Device will send these data via one uplink. (max value is 60, means max 60 sampling in one uplink)
• parameter5 & parameter6: Temperature alarm range is -16 to 32°C,
• parameter7: 1 to enable temperature alarm, 0 to disable the temperature alarm. If alarm is enabled, a data will be sent immediately  if temperate exceeds the Alarm range.

Downlink Command: 0xA5

0xA5 00 -- AT+WMOD=0.

0xA5 01 0A 11 94 29 04 -- AT+WMOD=1,10,45,105  (AT+WMOD = second byte, third byte, fourth and fifth bytes divided by 100, sixth and seventh bytes divided by 100 )

0XA5 01 0A F9 C0 29 04 --AT+WMOD=1,10,-16,105(Need to convert -16 to -1600 for calculation，-1600(DEC)=FFFFFFFFFFFFF9C0(HEX)  FFFFFFFFFFFFF9C0(HEX) +10000(HEX)=F9C0(HEX))

0xA5 02 0A 02 -- AT+WMOD=2,10,2  (AT+WMOD = second byte, third byte, fourth byte)

0xA5 03 01 00 3C 14 FF F0 00 20 01--AT+WMOD=3,1,60,20,-16,32,1

0xA5 FF -- After the device receives it, upload the current alarm configuration (FPORT=8). Such as 01 0A 11 94 29 04 or 02 0A 02.

4.16 Get Firmware Version Info(Since V1.4.0)

Feature: use downlink to get firmware version.

Downlink Command: 0x2601

Device will reply with firmware version info, device info. frequency band info. detail please check device user manual.

Total 7 bytes Example(FPort=5): 

Sensor model

0x0b: LHT65N

Firmware version

firm_ver=(bytes[1]&0x0f)+'.'+(bytes[2]>>4&0x0f)+'.'+(bytes[2]&0xOf);

Example: 0x0140=V1.4.0

 Frequency Band:

• 0x01: EU868
• 0x02: US915
• 0x03: IN865
• 0x04: AU915
• 0x05: KZ865
• 0x06: RU864
• 0x07: AS923
• 0x08: AS923-1
• 0x09: AS923-2
• 0xa0: AS923-3

Subband

value 0x00 ~ 0x08 

Example: 0xFF ---> " NULL"

Battery

Ex1:  0x0C4E(H) = 3150(D) = 3150mV =3.15V

Ex2:  0x0CF8(H) = 3320(D) = 3320mV =3.32V

5. Battery & How to replace

5.1 Battery Type

The minimum Working Voltage for the LHT65N is ~ 2.5v. When battery is lower than 2.6v, it is time to change the battery.
 

5.2 Replace Battery

LHT65N has two screws on the back, Unscrew them, and changing the battery inside is ok. The battery is a general CR17450 battery. Any brand should be ok.

5.3 Battery Life Analyze

6. FAQ

6.1 How to connect to LHT65N UART interface?

The LHT65N has the UART interface in its Type-C. The UART Interface can be used for

• Send AT Commands, and get output from LHT65N
• Upgrade firmwre of LHT65N.

The hardware connection is: PC <--> USB to TTL Adapter <--> Jump wires <--> Type-C Adapter <--> LHT65N

Option of USB TTL adapter:

• CP2101 USB TTL Adapter
• CH340 USB TTL Adapter
• FT232 USB TTL Adapter

Option of Type-C Adapter:

Connection:

• USB to TTL GND <--> LHT65N GND
• USB to TTL RXD <--> LHT65N TXD
• USB to TTL TXD <--> LHT65N RXD

Input password and ATZ to activate LHT65N,As shown below:

AT Command List is as below:

AT+<CMD>? :                  Help on <CMD>

AT+<CMD> :                   Run <CMD>

AT+<CMD>=<value> :   Set the value

AT+<CMD>=? :               Get the value

AT+DEBUG:    Set more info output

ATZ:                Trig a reset of the MCU

AT+FDR:         Reset Parameters to Factory Default, Keys Reserve

AT+DEUI:       Get or Set the Device EUI

AT+DADDR:   Get or Set the Device Address

AT+APPKEY:   Get or Set the Application Key

AT+NWKSKEY:   Get or Set the Network Session Key

AT+APPSKEY:     Get or Set the Application Session Key

AT+APPEUI:        Get or Set the Application EUI

AT+ADR:       Get or Set the Adaptive Data Rate setting. (0: off, 1: on)

AT+TXP:        Get or Set the Transmit Power (0-5, MAX:0, MIN:5, according to LoRaWAN Spec)

AT+DR:         Get or Set the Data Rate. (0-7 corresponding to DR_X)

AT+DCS:       Get or Set the ETSI Duty Cycle setting - 0=disable, 1=enable - Only for testing

AT+PNM:      Get or Set the public network mode. (0: off, 1: on)

AT+RX2FQ:    Get or Set the Rx2 window frequency

AT+RX2DR:    Get or Set the Rx2 window data rate (0-7 corresponding to DR_X)

AT+RX1DL:    Get or Set the delay between the end of the Tx and the Rx Window 1 in ms

AT+RX2DL:    Get or Set the delay between the end of the Tx and the Rx Window 2 in ms

AT+JN1DL:     Get or Set the Join Accept Delay between the end of the Tx and the Join Rx Window 1 in ms

AT+JN2DL:     Get or Set the Join Accept Delay between the end of the Tx and the Join Rx Window 2 in ms

AT+NJM:        Get or Set the Network Join Mode. (0: ABP, 1: OTAA)

AT+NWKID:    Get or Set the Network ID

AT+FCU:        Get or Set the Frame Counter Uplink

AT+FCD:        Get or Set the Frame Counter Downlink

AT+CLASS:    Get or Set the Device Class

AT+JOIN:       Join network

AT+NJS:        Get the join status

AT+SENDB:   Send hexadecimal data along with the application port

AT+SEND:     Send text data along with the application port

AT+RECVB:    Print last received data in binary format (with hexadecimal values)

AT+RECV:      Print last received data in raw format

AT+VER:        Get current image version and Frequency Band

AT+CFM:       Get or Set the confirmation mode (0-1)

AT+CFS:        Get confirmation status of the last AT+SEND (0-1)

AT+SNR:       Get the SNR of the last received packet

AT+RSSI:       Get the RSSI of the last received packet

AT+TDC:       Get or set the application data transmission interval in ms

AT+PORT:     Get or set the application port

AT+DISAT:    Disable AT commands

AT+PWORD: Set password, max 9 digits

AT+CHS:       Get or Set Frequency (Unit: Hz) for Single Channel Mode

AT+CHE:       Get or Set eight channels mode,Only for US915,AU915,CN470

AT+PDTA:      Print the sector data from start page to stop page

AT+PLDTA:    Print the last few sets of data

AT+CLRDTA:  Clear the storage, record position back to 1st

AT+SLEEP:     Set sleep mode

AT+EXT:        Get or Set external sensor model

AT+BAT:        Get the current battery voltage in mV

AT+CFG:        Print all configurations

AT+WMOD:   Get or Set Work Mode

AT+ARTEMP:  Get or set the internal Temperature sensor alarm range

AT+CITEMP:   Get or set the internal Temperature sensor collection interval in min

AT+SETCNT:   Set the count at present

AT+RJTDC:     Get or set the ReJoin data transmission interval in min

AT+RPL:         Get or set response level

AT+TIMESTAMP:   Get or Set UNIX timestamp in second

AT+LEAPSEC:        Get or Set Leap Second

AT+SYNCMOD:    Get or Set time synchronization method

AT+SYNCTDC:      Get or set time synchronization interval in day

AT+PID:                Get or set the PID

6.3 How to use Downlink commands?

Downlink commands:

TTN:

Helium: 

Chirpstack: The downlink window will not be displayed until the network is accessed

AWS-IOT :

6.4 How to change the uplink interval?

Please see this link: http://wiki.dragino.com/xwiki/bin/view/Main/How%20to%20set%20the%20transmit%20time%20interval/ 

6.5 How to upgrade firmware?

LHT65N has two types of firmware: Firmware with bootloader and Firmware without bootloader. Firmware Download Link:

Except  for the early batch of LHT65N, all LHT65N shipped since middle of 2023 already have bootloader by default, so user only need to use the firmware without bootloader to update, this is the most easy way.

6.5.1 Update firmware (Assume device already have bootloader)

Step1 : Connect UART as per FAQ 6.1

Step2 : Update follow Instruction for update via DraginoSensorManagerUtility.exe. Make sure to use the firmware without bootloader.

6.5.2 Update firmware (Assume device doesn't have bootloader)

In this update method, make sure to use the firmware with bootloader , Download Link  . After update , device will have bootloader so can use above 6.5.1 method to update.

Step1: Install TremoProgrammer  first.

Step2: Hardware Connection 

Connect PC and LHT65N via USB TTL adapter .

Note: Burn mode: Port4 (BOOT_CTL) of E2 cable connects 3V3 of USB-TTL.

Connection method:

USB-TTL GND <--> Port 1 of E2 cable

USB-TTL 3V3 <--> Port 4 of E2 cable

USB-TTL TXD <--> Port 9 of E2 cable

USB-TTL RXD <--> Port 5 of E2 cable

Step3: Select the device port to be connected, baud rate and bin file to be downloaded.

Reset node:  Short-circuit the port3(RST) of the E2 cable to GND.

Then click the start button to start the firmware upgrade.

When this interface appears, it indicates that the download has been completed.

Finally, Disconnect Port4 of E2 cable, reset the node again (Port3 shorted GND), and the node exits burning mode.

6.6 Why can't I see the datalog information

1. The time is not aligned, and the correct query command is not used.

2. Decoder error, did not parse the datalog data, the data was filtered.

6.7 How can i read sensor data without LoRaWAN? For Calibration Purpose

Some clients need to calibrate the sensor value in calibration Lab. In such case, Reading the data without LoRaWAN network is more convinient. To achieve this, use can use a USB Type-C Breakout board to expose the UART pins while still have the probe connected. See below. Detail Pin out please refer the FAQ of how to connect UART

After there is UART Connectio, run below commands:

1. AT+NJM=0   // Set Device to ABP mode , so can works without join to LoRaWAN server.

2. AT+GETSENSORVALUE=0      //The serial port gets the reading of the current sensor.

Example output:

7. Order Info

Part Number:  LHT65N-XX-YY

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

YY: Sensor Accessories

• E3: External Temperature Probe

8. Packing Info

Package Includes:

• LHT65N Temperature & Humidity Sensor x 1
• Optional external sensor

9. Reference material

• Datasheet, photos, decoder, firmware

10. FCC Warning

This device complies with part 15 of the FCC Rules.Operation is subject to the following two conditions:

(1) This device may not cause harmful interference;

(2) this device must accept any interference received, including interference that may cause undesired operation.