Dragino LT Series User manual

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LT Series LoRa IO controller User Manual 1 / 42
LT Series LoRa IO Controller User Manual
Document Version: 1.4.2
Image Version: v1.4
Version
Description
Date
1.0
Release
2018-Sep-26
1.0.2
Add 8 channels mode for US915, AU915, CN470
2018-Oct-24
1.0.3
Add current measure photo
2018-Nov-2
1.0.4
Add Cayenne connection guide
2018-Nov-24
1.1
Add downlink trouble shooting, Add Hardware Source code link.
Add change log for v1.1. (related to Downlink, Payload part)
Add TTN payload format
2019-Jan-24
1.1.1
Add more info for 8 channel mode descript and troubleshooting while use
US915 and AU915
2019-Feb-21
1.1.2
Modify trouble shooting for upload via FlashLoader,
2019-Apr-26

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LT Series LoRa IO controller User Manual 2 / 42
Correct the TTN payload decoder
1.2.0
Add Counting Mode
Improve description of single channel gateway compatible
1.2.1
Adjust Downlink instruction while using with LG01-N and LG02
2019-5-7
1.3.0
Add new feature on downlink, able to control the relay base on timing
2019-Aug-9
1.3.1
Add Power ON info
2019-Aug-20
1.4.0
Add LT-22222-L description and support.
Add Decode in LoRaserver
2020-Mar-7
1.4.1
Modify Downlink trouble shooting, Add MyDevice Photo
2020-Mar-28
1.4.2
Add Upgrade info for v1.4.2 firmware version
2020-Mar-30

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LT Series LoRa IO controller User Manual 3 / 42
1. Introduction..............................................................................................................................5
1.1 What is LT Series I/O Controller..................................................................................................5
1.2 Specifications..............................................................................................................................6
1.3 Features......................................................................................................................................7
1.4 Applications................................................................................................................................7
1.5Hardware Variants .....................................................................................................................8
1.6 Firmware Change log .................................................................................................................8
2. Power ON Device ....................................................................................................................10
3. Operation Mode ..................................................................................................................... 11
3.1 How it works?...........................................................................................................................11
3.2 Example to join LoRaWAN network..........................................................................................11
3.3 Uplink Payload..........................................................................................................................13
There are five working modes on LT for different type application: .............................................13
3.3.1 AT+MOD=1, 2ACI+2AVI ................................................................................................13
3.3.2 AT+MOD=2, (Double DI Counting) ..................................................................................14
3.3.3 AT+MOD=3, Single DI Counting + 2 x ACI........................................................................15
3.3.4 AT+MOD=4, Single DI Counting + 1 x Voltage Counting..................................................16
3.3.5 AT+MOD=5, Single DI Counting + 2 x AVI + 1 x ACI .........................................................16
3.3.6 Payload Decoder .............................................................................................................17
3.4 Downlink Payload.....................................................................................................................18
3.5 Integrate with Mydevice...........................................................................................................22
3.6 Interface Detail.........................................................................................................................25
3.6.1 Digital Input Port: DI1/DI2 /DI3 ( For LT-33222-L, low active ) .......................................25
3.6.2 Digital Input Port: DI1/DI2 ( For LT-22222-L) ..................................................................26
3.6.3 Digital Output Port: DO1/DO2 /DO3 ..............................................................................27
3.6.4 Analog Input Interface ....................................................................................................27
3.6.5 Relay Output ...................................................................................................................27
3.7 LEDs Indicators .........................................................................................................................29
4. Use AT Command....................................................................................................................30
4.1 Access AT Command.................................................................................................................30
4.2 Common AT Command Sequence.............................................................................................32
4.2.1 Multi-channel ABP mode (Use with SX1301/LG308) ......................................................32
4.2.2 Single-channel ABP mode (Use with LG01/LG02)...........................................................32

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4.2.3 Change to Class A............................................................................................................33
5. FAQ .........................................................................................................................................34
5.1 How to upgrade the image?.....................................................................................................34
5.2 How to change the LoRa Frequency Bands/Region? ................................................................36
5.3 How to set up LT to work in 8 channel mode in US915, AU915, CN470 bands? .......................36
5.4 How to set up LT to work with Single Channel Gateway such as LG01/LG02? .........................38
6. Trouble Shooting..................................................................................................................... 40
6.1 Downlink doesn’t work, how to solve it?..................................................................................40
6.2 Have trouble to upload image..................................................................................................40
6.3 Why I can’t join TTN in US915 /AU915 bands?.........................................................................40
7. Order Info ...............................................................................................................................40
8. Packing Info ............................................................................................................................40
9. Support................................................................................................................................... 41
10. Reference................................................................................................................................ 42

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LT Series LoRa IO controller User Manual 5 / 42
1. Introduction
1.1 What is LT Series I/O Controller
The Dragino LT series I/O Modules are Long Range LoRaWAN I/O Controller. It contains different
I/O Interfaces such as: analog current Input, analog voltage input, relay output, digital input and
digital output etc. The LT I/O Modules are designed to simplify the installation of I/O monitoring.
The LT I/O Controllers allows the user to send data and reach extremely long ranges. It provides
ultra-long range spread spectrum communication and high interference immunity whilst
minimizing current consumption. It targets professional wireless sensor network applications
such as irrigation systems, smart metering, smart cities, smartphone detection, building
automation, and so on.
The LT I/O Controllers is aiming to provide a simple plug and play, low cost installation by using
LoRaWAN wireless technology.
The use environment includes:
1) If user’s area has LoRaWAN service coverage, they can just install the I/O controller and
configure it to connect the LoRaWAN provider via wireless.
2) User can set up a LoRaWAN gateway locally and configure the controller to connect to the
gateway via wireless.

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LT Series LoRa IO controller User Manual 6 / 42
1.2 Specifications
Hardware System:
STM32L072CZT6 MCU
SX1276/78 Wireless Chip
Power Consumption:
Idle: 4mA@12v
20dB Transmit: 34mA@12v
Interface for Model: LT33222-L:
3 x Digital Input ( Detect Low signal , Max, 6V)
3 x Digital Output (NPN output. Max pull up voltage 36V,450mA)
2 x Relay Output (5A@250VAC / 30VDC)
2 x 0~20mA Analog Input (res:0.01mA)
2 x 0~30V Analog Input (res:0.01v)
Power Input 7~ 24V DC.

Interface for Model: LT22222-L:
2 x Digital dual direction Input (Detect High/Low signal, Max: 50v, or 220v with
optional external resistor)
2 x Digital Output (NPN output. Max pull up voltage 36V,450mA)
2 x Relay Output (5A@250VAC / 30VDC)
2 x 0~20mA Analog Input (res:0.01mA)
2 x 0~30V Analog Input (res:0.01v)
Power Input 7~ 24V DC.
LoRa Spec:
Frequency Range:
Band 1 (HF): 862 ~ 1020 Mhz
Band 2 (LF): 410 ~ 528 Mhz
168 dB maximum link budget.
+20 dBm - 100 mW constant RF output vs.
+14 dBm high efficiency PA.
Programmable bit rate up to 300 kbps.
High sensitivity: down to -148 dBm.
Bullet-proof front end: IIP3 = -12.5 dBm.
Excellent blocking immunity.
Low RX current of 10.3 mA, 200 nA register retention.
Fully integrated synthesizer with a resolution of 61 Hz.
FSK, GFSK, MSK, GMSK, LoRaTM and OOK modulation.
Built-in bit synchronizer for clock recovery.
Preamble detection.

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127 dB Dynamic Range RSSI.
Automatic RF Sense and CAD with ultra-fast AFC.
Packet engine up to 256 bytes with CRC.
1.3 Features
LoRaWAN Class A & Class C protocol
Optional Customized LoRa Protocol
Frequency Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915/RU864/IN865
AT Commands to change parameters
Remote configure parameters via LoRa Downlink
Firmware upgradable via program port
Counting
1.4 Applications
Smart Buildings & Home Automation
Logistics and Supply Chain Management
Smart Metering
Smart Agriculture
Smart Cities
Smart Factory

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1.5 Hardware Variants
Model
Photo
Description
LT33222-L
3 x Digital Input
3 x Digital Output
2 x Relay Output (5A@250VAC / 30VDC)
2 x 0~20mA Analog Input (res:0.01mA)
2 x 0~30V Analog Input (res:0.01v)
1 x Counting Port
Model
Photo
Description
LT22222-L
2 x Digital Input (Bi-direction)
2 x Digital Output
2 x Relay Output (5A@250VAC / 30VDC)
2 x 0~20mA Analog Input (res:0.01mA)
2 x 0~30V Analog Input (res:0.01v)
1 x Counting Port
1.6 Firmware Change log
LT Image files
Image v1.4.2
Update LoRaWAN stack to DR-LWS-003
(http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/DR-LWS/&file=chang
elog )
Fix DO / Relay state lose after reboot. Now After reboot, the DO/Relay will keep the same
state as before.
Image v1.4.1
Fix watchdog bug. This bug cause some device will un-stop reboot with the v1.4 firmware.
Image v1.4
Add hardware support for LT-22222-L
Update LoRaWAN stack to DR-LWS-002
Change to Class C by default
Add Software Watchdog
Re-construct Payload format, use the new decoder for v1.4.
Add Downlink command to pre-set count number
First bug for endless loop when TDC is too small

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Image v1.3
Add clear counting feature via Downlink
Improve Downlink type code 0x03 to support control RO1 or RO2 separately.
Add Downlink type code 0x05
Add Downlink type code 0x07
Image v1.2
Add counting feature
Image v1.1
Voltage and Current reserve three decimal, previous is two
Can use any Fport for downlink
Add AT+CFG to print all settings
Fix current and voltage glith bug

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2. Power ON Device
The LT controller can be powered by 7 ~ 24V DC power source. Connect VIN to Power Input V+
and GND to power input V- to power the LT controller.
PWR will on when device is properly powered.

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3. Operation Mode
3.1 How it works?
The LT is configured as LoRaWAN OTAA Class C mode by default. It has OTAA keys to join network.
To connect a local LoRaWAN network, user just need to input the OTAA keys in the network
server and power on the LT. It will auto join the network via OTAA. For LT-22222-L, the LED will
show the Join status: After power on TX LED will fast blink 5 times, LT-22222-L will enter working
mode and start to JOIN LoRaWAN network. TX LED will be on for 5 seconds after joined in
network. When there is message from server, the RX LED will be on for 1 second.
In case user can’t set the OTAA keys in the network server and has to use the existing keys from
server. User can use AT Command to set the keys in the devices.
3.2 Example to join LoRaWAN network
This chapter shows an example for how to join the TTN LoRaWAN Network. Below is the network
structure, we use our LG308 as LoRaWAN gateway here.
The LG308 is already set to connect to TTN network . So what we need to do now is only
configure register this device to TTN:
Step 1: Create a device in TTN with the OTAA keys from LT IO controller.
Each LT is shipped with a sticker with the default device EUI as below:

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Input these keys in the LoRaWAN Server portal. Below is TTN screen shot:
Add APP EUI in the application.
Add APP KEY and DEV EUI
Step 2: Power on LT and it will auto join to the TTN network. After join success, it will start to
upload message to TTN and user can see in the panel.

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3.3 Uplink Payload
There are five working modes on LT for different type application:
MOD1: (default setting): 2 x ACI + 2AVI + DI + DO + RO
MOD2: Double DI Counting + DO + RO
MOD3: Single DI Counting + 2 x ACI + DO + RO
MOD4: Single DI Counting + 1 x Voltage Counting + DO + RO
MOD5: Single DI Counting + 2 x AVI + 1 x ACI + DO + RO
3.3.1 AT+MOD=1, 2ACI+2AVI
The uplink payload includes totally 9 bytes. Uplink packets use FPORT=2 and every 10 minutes
send one uplink by default.
Size(bytes)
2
2
2
2
1
1
1
Value
AVI1
voltage
AVI2
voltage
ACI1
Current
ACI2
Current
DIDORO*
Reserve
MOD
DIDORO is a combination for RO1, RO2, DI3, DI2, DI1, DO3, DO2 and DO1. Totally 1bytes as below
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
RO1
RO2
DI3
DI2
DI1
DO3
DO2
DO1
RO is for relay. ROx=1 : close，ROx=0 always open.
DI is for digital input. DIx=1: high or float, DIx=0: low.
DO is for reverse digital output. DOx=1: output low, DOx=0: high or float.
Note: DI3 and DO3 bit are not valid for LT-22222-L
For example if payload is: 04 AB 04 AC 13 10 13 00 AA FF 01
The value for the interface is:
AVI1 channel voltage is 0x04AB/1000=1195（DEC）/1000=1.195V
AVI2 channel voltage is 0x04AC/1000=1.196V
ACI1 channel current is 0x1310/1000=4.880mA
ACI2 channel current is 0x1300/1000=4.864mA
The last byte 0xAA= 10101010(B) means 
[1] RO1 relay channel is close and the RO1 LED is ON.
[0] RO2 relay channel is open and RO2 LED is OFF;
LT33222-L:
[1] DI3 channel is high input and DI3 LED is OFF;
[0] DI2 channel is low input;
[1] DI1 channel is high input and DI1 LED is OFF;
LT22222-L:
[1] DI2 channel is high input and DI2 LED is ON;
[0] DI1 channel is low input;

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LT Series LoRa IO controller User Manual 14 / 42
[0] DO3 channel output state
DO3 is float in case no load between DO3 and V+.;
DO3 is high in case there is load between DO3 and V+.
DO3 LED is off in both case
[1] DO2 channel output is low and DO2 LED is ON.
[0] DO1 channel output state
DO1 is float in case no load between DO1 and V+.;
DO1 is high in case there is load between DO1 and V+.
DO1 LED is off in both case
3.3.2 AT+MOD=2, (Double DI Counting)
For LT-33222-L: this mode the DI3 is used as a counting pin. Counting on DI3 reflect in COUNT1.
For LT-22222-L: this mode the DI1 and DI2 are used as counting pins.
Total : 11 bytes payload
Size(bytes)
4
4
1
1
1
Value
COUNT1
COUNT2
DIDORO*
Reserve
MOD
DIDORO is a combination for RO1, RO2, DO3, DO2 and DO1. Totally 1bytes as below
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
RO1
RO2
FIRST
Reserve
Reserve
DO3
DO2
DO1
RO is for relay. ROx=1 : close，ROx=0 always open.
FIRST: Indicate this is the first packet after join network.
DO is for reverse digital output. DOx=1: output low, DOx=0: high or float.
Note: DO3 bit is not valid for LT-22222-L.
To use counting mode, please run:
AT+MOD=2
ATZ
AT Commands for counting:
For LT33222-L:
AT+TRIG=0,100, 3 (set DI3 port to trigger on low level, valid signal is 100ms)
AT+TRIG=1,100, 3 (set DI3 port to trigger on high level, valid signal is 100ms )
AT+SETCNT=1,60 (Set COUNT1 value to 60)
For LT22222-L:
AT+TRIG=0,100, 1 (set DI1 port to trigger on low level, valid signal is 100ms)
AT+TRIG=1,100, 1 (set DI1 port to trigger on high level, valid signal is 100ms )

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AT+TRIG=0,100, 2 (set DI2 port to trigger on low level, valid signal is 100ms)
AT+TRIG=1,100, 2 (set DI2 port to trigger on high level, valid signal is 100ms )
AT+SETCNT=1,60 (Set COUNT1 value to 60)
AT+SETCNT=2,60 (Set COUNT2 value to 60)
For both LT22222-L & LT33222-L:
AT+CLRCOUNT clear all countings
AT+COUTIME=60 Set save time to 60 seconds. Device will save the counting result in internal
flash every 60 seconds. (min value: 30)
3.3.3 AT+MOD=3, Single DI Counting + 2 x ACI
LT33222-L: This mode the DI3 is used as a counting pin.
LT22222-L:This mode the DI1 is used as a counting pin.
Size(bytes)
4
2
2
1
1
1
Value
COUNT1
ACI1
Current
ACI2
Current
DIDORO*
Reserve
MOD
DIDORO is a combination for RO1, RO2, DI3, DI2, DI1, DO3, DO2 and DO1. Totally 1bytes as below
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
RO1
RO2
FIRST
Reserve
Reserve
DO3
DO2
DO1
RO is for relay. ROx=1 : close，ROx=0 always open.
FIRST: Indicate this is the first packet after join network.
DO is for reverse digital output. DOx=1: output low, DOx=0: high or float.
Note: DO3 is not valid for LT-22222-L.
To use counting mode, please run:
AT+MOD=3
ATZ
Other AT Commands for counting are similar to MOD2 Counting Command.

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3.3.4 AT+MOD=4, Single DI Counting + 1 x Voltage Counting
LT33222-L: This mode the DI3 is used as a counting pin.
LT22222-L:This mode the DI1 is used as a counting pin.
The AVI1 is also used for counting. AVI1 is used to monitor the voltage. It will check the voltage
every minute, if voltage is higher than VOLMAX mV, the AVI1 Counting increase 1, so AVI1
counting can be used to measure a machine working hour.
Size(bytes)
4
4
1
1
1
Value
COUNT1
AVI1
Counting
DIDORO*
Reserve
MOD
DIDORO is a combination for RO1, RO2, DI3, DI2, DI1, DO3, DO2 and DO1. Totally 1bytes as below
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
RO1
RO2
FIRST
Reserve
Reserve
DO3
DO2
DO1
RO is for relay. ROx=1 : close，ROx=0 always open.
FIRST: Indicate this is the first packet after join network.
DO is for reverse digital output. DOx=1: output low, DOx=0: high or float.
Note: DO3 is not valid for LT-22222-L.
To use this mode, please run:
AT+MOD=4
ATZ
Other AT Commands for counting are similar to MOD2 Counting Command.
Plus below command for AVI1 Counting:
AT+SETCNT=3,60 (set AVI Count to 60)
AT+VOLMAX=20000 (Set VOLMAX to 20000mV =20v)
3.3.5 AT+MOD=5, Single DI Counting + 2 x AVI + 1 x ACI
LT33222-L: This mode the DI3 is used as a counting pin.
LT22222-L:This mode the DI1 is used as a counting pin.
Size(bytes)
2
2
2
2
1
1
1
Value
AVI1
voltage
AVI2
voltage
ACI1
Current
COUNT1
DIDORO*
Reserve
MOD

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DIDORO is a combination for RO1, RO2, DI3, DI2, DI1, DO3, DO2 and DO1. Totally 1bytes as below
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
RO1
RO2
FIRST
Reserve
Reserve
DO3
DO2
DO1
RO is for relay. ROx=1 : close，ROx=0 always open.
FIRST: Indicate this is the first packet after join network.
DO is for reverse digital output. DOx=1: output low, DOx=0: high or float.
Note: DO3 is not valid for LT-22222-L.
To use this mode, please run:
AT+MOD=5
ATZ
Other AT Commands for counting are similar to MOD2 Counting Command.
3.3.6 Payload Decoder
Decoder for TTN/loraserver/ChirpStack:
http://www.dragino.com/downloads/index.php?dir=LT_LoRa_IO_Controller/LT33222-L/Payload_decoder/

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3.4 Downlink Payload
Downlink Control Type
Type Code
Downlink
payload
size(bytes)
TDC (Transmit Time Interval)
01
4
Digital Output (DO1DO2DO3)
02
4
Relay Output (RO1RO2)
03
3
RESET
04
2
Relay Output CTL (RO1RO2) (with time control)
05
5
Poll an Uplink
08
2
Clear Counting(Same as AT+CLRCOUNT )
A6
2
Change counting mode save time(Same as
AT+COUTIME)
A7
4
AT+SETCNT (Pre-configure the Count Number)
A8
6
Digital Output CTL (DO1DO2DO3) (with time
control)
A9
7
The FPort is not fix, if the payload=0100003C, means to control the END Node’s TDC to
0x00003C=60(S), while type code is 01.
Example Downlink payload setting in TTN:
Type Code 02:
If payload = 0x02010001, while there is load between V+ and DOx, it means set DO1 to low , DO2
to high and DO3 to low. Type code 02 means Digital Output
01: Low, 00: High , 11: No action
Downlink Code
DO1
DO2
DO3
02 01 00 11
Low
High
No Action
02 00 11 01
High
No Action
Low
02 11 01 00
No Action
Low
High
Note: For LT-22222-L, there is no DO3, the last byte can use any value.
Device will upload a packet if downlink code execute successfully.

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Type Code 03:
If payload = 0x030100, it means set RO1 to close and RO2 to open.
01: Close , 00: Open , 11: No action
Downlink Code
RO1
RO2
03 00 11
Open
No Action
03 01 11
Close
No Action
03 11 00
No Action
Open
03 11 01
No Action
Close
03 00 00
Open
Open
03 01 01
Close
Close
03 01 00
Close
Open
03 00 01
Open
Close
Device will upload a packet if downlink code execute successfully.
Type Code 04:
If payload = 0x04FF, it will reset the LT.
Type Code 05:
This is to control the relay output time of relay. Include four bytes:
First Byte: Type code (0x05)
Second Byte: Inverter Mode
01: Relays will change back to original state after timeout.
00: Relays will change to an inverter state after timeout
Third Byte: Control Method and Ports status:
Value
Status
0x11
RO1 and RO2 to NO
0x10
RO2 to NO, RO1 to NC
0x01
RO2 to NC, RO1 to NO
0x00
RO1 and RO2 to NC.
0x20
RO1 No Action, RO2 to NC
0x21
RO1 No Action, RO2 to NO
0x02
RO1 to NC, RO2 No Action
0x12
RO1 to NO, RO2 No Action
Fourth / Fifth Bytes: Latching time. Unit: ms
Device will upload a packet if downlink code execute successfully.
Example payload:
a) 05 01 11 07 D0

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Relay1 and Relay 2 will be set to NO , last 2 seconds, then change back to original state.
b) 05 01 10 07 D0
Relay1 will change to NO, Relay2 will change to NC, last 2 seconds, then both change back to
original state.
c) 05 00 01 07 D0
Relay1 will change to NC, Relay2 will change to NO, last 2 seconds, then relay change to NO,
Relay2 change to NC.
d) 05 00 00 07 D0
Relay 1 & relay2 will change to NC, last 2 seconds, then both change to NO.
Type Code 08: (Applicable for firmware since v1.4)
Poll an uplink,
Example: 0x08FF, Ask device to send an Uplink
Type Code A6: (Applicable for firmware since v1.3)
Downlink to clear counting to 0, same as AT+CLRCOUNT
Example: 0xA601: Clear Counting
Type Code A7: (Applicable for firmware since v1.3)
Downlink to change counting mode, same as AT+COUTIME
Example: 0x A700003C: Change counting save time to 60s (0x3C)
Type Code A8:
Total bytes: 6
Example: 0xA8 01 00 00 00 00: pre-set the counting number
2nd byte: stands for the count number.
01: Set COUNT1 count value
02: Set COUNT2 count value
03: Set AV1 count number.
3rd ~ 6th bytes: the new value in hex format: 00 00 00 AB: count: 0xAB = 171.
Digital Output CTL (DO1DO2DO3)
A9
7