Table of Contents:

• 1. Introduction
  • 1.1 What is T68DL LoRaWAN Temperature Sensor
  • 1.2 Features
  • 1.3 Specification
• 2. Connect T68DL to IoT Server
  • 2.1 How does T68DL work?
  • 2.2 How to Activate T68DL?
  • 2.3 Quick guide to connect to LoRaWAN server (OTAA)
  • 2.4 Uplink Payload
    • 2.4.1 Device Status, FPORT=5
    • 2.4.2 Real-Time Temperature data, Uplink FPORT=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 Threshold alarm with built-in temperature sensor (TMP116)
    • 2.7.2 Fluctuation alarm for TMP116
    • 2.7.3 Sampling multiple times and uplink together
• 3. Configure T68DL via AT command or LoRaWAN downlink
  • 3.1 Set Transmit Interval Time
  • 3.2 Set Password
  • 3.3 Quit AT Command
  • 3.4 Set to sleep mode
  • 3.5 Set system time
  • 3.6 Set Time Sync Mode
  • 3.7 Set Time Sync Interval
  • 3.8 Get data
  • 3.11 Print data entries base on page
  • 3.12 Print last few data entries
  • 3.13 Clear Flash Record
  • 3.14 Auto Send None-ACK messages
  • 3.15 high datarate function
  • 3.16 Revised WMOD Command for Internal Sensor TMP116 Temperature Alarms
• 4. Battery
  • 4.1 Battery Type
  • 4.2 Power Consumption Analyze
• 5. OTA Firmware update
• 6. FAQ
  • 6.1 Why can't I see the datalog information
• 7. Order Info
• 8. Packing Info
• 9. Support

1. Introduction

1.1 What is T68DL LoRaWAN Temperature 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 can be upgraded via OTA
• Built-in 2400mAh battery for up to 10 years of use.
• Built-in Temperature sensor
• 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

2. Connect T68DL to IoT Server

2.1 How does T68DL work?

2.2 How to Activate T68DL?

• Deep Sleep Mode: T68DL doesn't have any LoRaWAN activities. This mode is used for storage and shipping to save battery life.

• Working Mode: In this mode, T68DL works as LoRaWAN Sensor mode to Join LoRaWAN network and send out the sensor data to the server. Between each sampling/tx/rx periodically, T68DL will be in STOP mode (IDLE mode), in STOP mode, T68DLhas the same power consumption as Deep Sleep mode.  

2.3 Quick guide to connect to LoRaWAN server (OTAA)

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.

Step 1: Create a device in TTN V3 with the OTAA keys from T68DL.

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

Create the application.

Add devices to the created Application.

Enter end device specifics manually.

Step 2: Add decoder

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

Click this link to get the decoder: T68DL decoder.

Below is TTN screen shot:

Step 3: Power on T68DL and it will auto join to the TTN V3 network. After join success, it will start to upload message to TTN V3 and user can see in the panel.

2.4 Uplink Payload

2.4.1 Device Status, FPORT=5

Users can use the downlink command(0x26 01) to ask T68DL to send device configure detail, include device configure status. T68DL will uplink a payload via FPort=5 to server.

The Payload format is as below.

Example parse in TTNv3:

Sensor Model: For T68DL, this value is 0x34

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: 0x0CD5 = 3285mV

Ex2: 0x0B49 = 2889mV

2.4.2 Real-Time Temperature data, Uplink FPORT=2

• Battery

Check the battery voltage.

Example: 0x0CBF(H)= 3263(D) mV

• Built-In Temperature (TMP116)

Example:

If payload is: 0x0AFE:  (0AFE & 8000 == 0), temp = 0AFEH/10 = 28.14 degree

If payload is: 0xFF3F :  (FF3F & 8000 == 1) , temp = (FF3FH - 65536)/10 = -19.3 degrees.

(FF3F & 8000:Judge whether the highest bit is 1, when the highest bit is 1, it is negative)

• TEMPH_flag & TEMPL_flag

Example:

TEMPH_flag:

If payload is: 0x02:  (0x02 & 0x01 == 0), TEMPH_flag = False

If payload is: 0x01:  (0x01 & 0x01 == 1). TEMPH_flag = True

TEMPL_flag:

If payload is: 0x01:  (0x01 & 0x02 == 0), TEMPL_flag = False

If payload is: 0x02:  (0x02 & 0x02 == 1). TEMPL_flag = True

• Data_time

Unit TimeStamp Example: 671F024A(H) = 1730085450(D)

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

Example parse in TTNv3: 

2.5 Show data on Datacake

Step 1: Link TTNv3 to Datacake. https://docs.datacake.de/lorawan/lns/thethingsindustries#create-integration-on-tti

Step 2: Add T68DL to Datacake. Go to TTN V3 Console --> Applications --> Integrations --> Add Integrations.

Step 3: Configure T68DL in Datacake.

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, T68DL will wait for ACK for every uplink, when there is no LoRaWAN network, T68DL 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) T68DL will do an ACK check for data records sending to make sure every data arrive server.
• b) T68DL will send data in CONFIRMED Mode when PNACKMD=1, but T68DL 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 T68DL gets a ACK, T68DL 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

T68DL 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=1730085450 or downlink 30671F024A to set the current time 2024 – October -- 28 Monday 3:17:30

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  67180C82  671836B2  05 

Is to check 2024/10/22 20:35:14 to 2024/10/22 23:35:14's data

Uplink Internal =5s, means T68DL 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:

ACK message flag:

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 T68DL has below data inside Flash:

If user sends below downlink command:  31 67180C82 671836B2 05

Where : Start time: 67180C82 = time 24/10/24 20:35:14

             Stop time:  671836B2 = time 24/10/24 23:35:14

T68DL will uplink this payload.

FFFFFFFF 0B4040 67180C82

FFFFFFFF0B424067181132FFFFFFFF0B4540671815E2FFFFFFFF0AFA4067181A92FFFFFFFF0AF64067181F42FFFFFFFF0AFD40671823F2FFFFFFFF0AF940671828A2FFFFFFFF0AFC4067182D52FFFFFFFF0AFD4067183202FFFFFFFF0AEE40671836B2

Where the first 11 bytes is for the first entry:

FFFFFFFF 0B40 40 67180C82

Bytes not used, so reserved: FFFFFFFF

Temp=0x0B40/100=28.8℃

PNACK status flag: ((bytes[6]>>7)&0x01) ? "True":"False" =(0x40>>7)&0x01=0

Unix time is 0x67180C82=1729629314s=24/10/22 20:35:14

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

3. Configure T68DL via AT command or LoRaWAN downlink

• AT Command Connection: 

  

• 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 T68DL

3.1 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

3.2 Set Password

Feature: Set device password, max 9 digits

AT Command: AT+PWORD

Downlink Command:

No downlink command for this feature.

3.3 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.

3.4 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.

3.5 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

3.6 Set Time Sync Mode

AT Command:

Downlink Command:

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

3.7 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

3.8 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.

3.11 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

3.12 Print last few data entries

Feature: Print the last few data entries

AT Command: AT+PLDTA

Downlink Command:

No downlink commands for feature

3.13 Clear Flash Record

Feature: Clear flash storage for data log feature.

AT Command: AT+CLRDTA

Downlink Command: 0xA3

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

3.14 Auto Send None-ACK messages

Feature: T68DL will wait for ACK for each uplink, If T68DL doesn't get ACK from the IoT server, it will consider the message doesn't arrive server and store it. T68DL keeps sending messages in normal periodically. Once T68DL 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

3.15 high datarate function

Feature:  Enable or disable high datarate

AT Command: AT+HDR

The default factory setting is 0

Downlink Command: 0xA1

• Example: 0xA101       //  Same as AT+HDR=1
• Example: 0xA100       //  Same as AT+HDR=0

3.16 Revised WMOD Command for Internal Sensor TMP116 Temperature Alarms

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: Sampling Interval is 60s.
• parameter3: 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)
• parameter4 & parameter5: Temperature alarm range is -16 to 32°C,
• parameter6: 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  00 3C 14 FF F0 00 20 01--AT+WMOD=3,60,20,-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. Battery

4.1 Battery Type

The minimum Working Voltage for the T68DL is about 2.5v. When battery is lower than 2.6v, it is time to change the battery.

4.2 Power Consumption Analyze

Dragino battery powered products are all run in Low Power mode. User can check the guideline from this link to calculate the estimate battery life:

Battery Info & Power Consumption Analyze .

5. OTA Firmware update

User can change firmware T68DL 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 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.

7. Order Info

Part Number:  T68DL-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

8. Packing Info

Package Includes:

• T68DL Temperature Sensor x 1

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.