Temperature & Humidity sensor LR-MU-TH-IP65 – LoRa@VSB – LoRaWAN Network of Technical University of Ostrava Campus

TTN version:	TTNv3
Frequency:	Europe 863-870 MHz (SF9 for RX2 – recommended)
Activation:	OTAA / ABP
Device Class:	Class A
Last updated:	December 6, 2023

One of the commercial products we use is the temperature and humidity sensor LR-MU-TH-IP65 from Solidus TECH. At the device’s heart is a RHF76-052DM, which can be used for transmission/reception in the 434 – 915 MHz range. To measure temperature and humidity, the device uses a temperature and humidity sensor SHT31. The sensor measures temperatures in the range of -40 ºC to 85 ºC and humidity in the range of 0 to 100%. The accuracy of temperature measurement is ± 0.5 ºC and humidity ± 3%. The device is available on the company’s website with the code LOR-MU-TH-IP65. Temperature and humidity sensor

Prepare

Serial Monitor setup

Download Visual Studio Code.
Run Visual Studio Code.
In the VS Code Extensions -> search Serial Monitor by Microsoft -> Install.
Open a new terminal via Terminal -> New Terminal.
In the SERIAL MONITOR tab, set the parameters according to the following image:

Activation

Over The Air Activation (OTAA) – the most secure and recommended activation method for end devices. Devices perform a join procedure with the network, during which a dynamic device address is assigned and security keys are negotiated with the device.

Activation By Personalization (ABP) – requires hardcoding the device address as well as the security keys in the device. ABP is less secure than OTAA and also has the downside that devices can not switch network providers without manually changing keys in the device.

See the documentation for more information on activation.

Over The Air Activation (OTAA)

Add LR-MU-TH-IP65 into The Things Stack

Create an account on The Things Network if you don’t have one.
Login on The Things Network.
Click on your username and choose Console.
Select a network cluster.

Add application

Go to applications.
Click on button + Create application.
Write something into Application ID.
Click on button Create application.

Add end device

In your application click on button + Register end device.
Input Method – Choose Enter end device specifics manually.
Frequency plan – Europe 863-870 MHz (SF9 for RX2 – recommended)
LoRaWAN version – LoRaWAN Specification 1.0.3
Click on Show advanced activation, LoRaWAN class and cluster settings
Activation mode – Over the air activation (OTAA)
Additional LoRaWAN class capabilities – None (class A only)
Deselect – Use network’s default MAC settings
Rx2 data rate = 3
Rx2 frequency = 869,525 MHz
JoinEUI – 0000000000000000
Click on Confirm.
DevEUI – Generate
AppKey – Generate
End device ID – here you can name your device
After registration – View registered end device
Click on button Register end device
Click on General settings
Network layer – Expand
Click on Advanced MAC settings
Desired Rx1 delay = 1
Rx1 data rate offset = 0
Add Frequency = 868100000
Add Frequency = 868300000
Add Frequency = 868500000
Add Frequency = 867100000
Add Frequency = 867300000
Add Frequency = 867500000
Add Frequency = 867700000
Add Frequency = 867900000
Adaptive data rate (ADR) – Dynamic mode
Click on button Save changes

Payload formatters

In TTS -> Applications -> YourAppName -> YourEndDeviceName -> Payload formatters -> Uplink change Formatter type to Custom Javascript formatter and to Formatter code copy and paste code bellow:

function decodeUplink(input) {
  let payload = input.bytes;
  let voltage = payload[0];
  let temperature = (payload[1] << 8) | payload[2];
  let humidity = (payload[3] << 8) | payload[4];
   
  let decodedVoltage = voltage * 30 / 1000;
  let decodedTemperature = temperature / 10;
  let decodedHumidity = humidity / 10;

  let decodedPayload = {
    'voltage': decodedVoltage,
    'temperature': decodedTemperature,
    'humidity': decodedHumidity
  };

  return {
    data: decodedPayload,
    warnings: [],
    errors: []
  };
}

Save changes

LR-MU-TH-IP65 setup

Connect LR-MU-TH-IP65 using USB TTL UART converter – 3,3 V and USB cable to your computer. (Pin order in the image is from left to right – GND, CTS, VCC, TX, RX, DTR).
In VS Code, in SERIAL MONITOR, select Port and press the Start Monitoring button.
To set up LR-MU-TH-IP65, enter the following individual commands line by line into SERIAL MONITOR and send them to the device. Replace AppEui, DevEui and APPKEY with keys in TTS. Keys are in TTS -> Applications -> YourAppName -> YourEndDeviceName -> Overview -> Activation information:
```
show
AT+FDEFAULT
AT+CLASS=A
AT+MODE="OTAA"
AT+ID=AppEui, "0000000000000000"
AT+ID=DevEui, "0000000000000000"
AT+KEY=APPKEY, "00000000000000000000000000000000"
AT+POWER=14
AT+ADR=on
message:1
sleep:10
scan:10
reset
```
After entering and submitting the last command, you should see a listing similar to the one in the following image:
In TTS -> Applications -> YourAppName -> YourEndDeviceName -> Live data you should every 10 minutes see this:

Subsequent setup using a downlinks

A1XXXX – Periodic sleep setting, where XXXX is the decimal value of the sleep parameter. For example, A10005 sets the periodic mode to 5 min., A10120 sets the periodic mode to 120 min.

A2XX – Uplink message type setting, where XX is either 01 for UNCONFIRMED messages and 02 for CONFIRMED messages.

A3XX – DR type setting where XX is 00 to 05 which corresponds to SF12 to SF7.

A4XX – ADR enable/disable where XX is either 01 for ADR enable type messages and 02 for ADR disable.

Other optional AT commands

You can find more commands in the module documentation.

Data visualization

If you want to visualize your measured data, continue with the following tutorial:

Telegraf & InfluxDB & Grafana

Activation By Personalization (ABP)