Contents:

1.  Introduction

1.1 ​ What is LoRaWAN Distance Detection Sensor

​1.2  Features

• LoRaWAN 1.0.3 Class A
• Ultra low power consumption
• Distance Detection by Ultrasonic technology
• Flat object range 280mm - 7500mm
• Accuracy: ±(1cm+S*0.3%) (S: Distance)
• Cable Length : 25cm
• Bands: CN470/EU433/KR920/US915/EU868/AS923/AU915/IN865
• AT Commands to change parameters
• Uplink on periodically
• Downlink to change configure
• IP66 Waterproof Enclosure
• 4000mAh or 8500mAh Battery for long term use

1.3  Specification

1.3.1  Rated environmental conditions

Remarks: (1)  a. When the ambient temperature is 0-39 ℃, the maximum humidity is 90% (non-condensing);

b. When the ambient temperature is 40-50 ℃, the highest humidity is the highest humidity in the natural world at the current temperature (no condensation)

1.3.2  Effective measurement range Reference beam pattern

(1) The tested object is a white cylindrical tube made of PVC, with a height of 100cm and a diameter of 7.5cm.

(2) The object to be tested is a "corrugated cardboard box" perpendicular to the central axis of 0 °, and the length * width is 60cm * 50cm.

1.5 ​ Applications

• Horizontal distance measurement
• Liquid level measurement
• Parking management system
• Object proximity and presence detection
• Intelligent trash can management system
• Robot obstacle avoidance
• Automatic control
• Sewer
• Bottom water level monitoring

1.6  Pin mapping and power on

2.  Configure LDDS75 to connect to LoRaWAN network

2.1  How it works

2.2  ​Quick guide to connect to LoRaWAN server (OTAA)

For OTAA registration, we need to set APP EUI/ APP KEY/ DEV EUI. Some server might no need to set APP EUI.

Enter these keys in the LoRaWAN Server portal. Below is TTN V3 screen shot:

Add APP EUI in the application

You can also choose to create the device manually.

Add APP KEY and DEV EUI

Step 2: Power on LDDS75

Put a Jumper on JP2 to power on the device. ( The Switch must be in FLASH position).

2.3  ​Uplink Payload

2.3.1  Battery Info

Check the battery voltage for LDDS75.

Ex1: 0x0B45 = 2885mV

Ex2: 0x0B49 = 2889mV

2.3.2  Distance

Get the distance. Flat object range 280mm - 7500mm.

For example, if the data you get from the register is 0x0B 0x05, the distance between the sensor and the measured object is 0B05(H) = 2821 (D) = 2821 mm.

• If the sensor value is 0x0000, it means system doesn’t detect ultrasonic sensor.
• If the sensor value lower than 0x0118 (280mm), the sensor value will be invalid. Since v1.1.4, all value lower than 280mm will be set to 0x0014(20mm) which means the value is invalid.

2.3.3  Interrupt Pin

This data field shows if this packet is generated by interrupt or not. Click here for the hardware and software set up.

Example:

0x00: Normal uplink packet.

0x01: Interrupt Uplink Packet.

2.3.4  DS18B20 Temperature sensor

This is optional, user can connect external DS18B20 sensor to the +3.3v, 1-wire and GND pin . and this field will report temperature.

Example:

If payload is: 0105H:  (0105 & FC00 == 0), temp = 0105H /10 = 26.1 degree

If payload is: FF3FH :  (FF3F & FC00 == 1) , temp = (FF3FH - 65536)/10 = -19.3 degrees.

Note: DS18B20 feature is supported in the hardware version > v1.3 which made since early of 2021.

2.3.5  Sensor Flag

0x01: Detect Ultrasonic Sensor

0x00: No Ultrasonic Sensor

2.3.6  Decode payload in The Things Network

While using TTN network, you can add the payload format to decode the payload.

The payload decoder function for TTN V3 is here:

LDDS75 TTN V3 Payload Decoder: http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LDDS75/Payload_Decoder/

2.4  Uplink Interval

The LDDS75 by default uplink the sensor data every 20 minutes. User can change this interval by AT Command or LoRaWAN Downlink Command. See this link: Change Uplink Interval

2.5  ​Show Data in DataCake IoT Server

Step 3: Create an account or log in Datacake.

Step 4: Search the LDDS75 and add DevEUI.

After added, the sensor data arrive TTN V3, it will also arrive and show in Datacake.

2.6  Frequency Plans

2.6.1  EU863-870 (EU868)

2.6.2  US902-928(US915)

2.6.3  CN470-510 (CN470)

2.6.4  AU915-928(AU915)

2.6.5  AS920-923 & AS923-925 (AS923)

2.6.6  KR920-923 (KR920)

2.6.7  IN865-867 (IN865)

2.7  LED Indicator

The LDDS75 has an internal LED which is to show the status of different state. 

• Blink once when device power on.
• The device detects the sensor and flashes 5 times.
• Solid ON for 5 seconds once device successful Join the network.
• Blink once when device transmit a packet.

2.8  ​Firmware Change Log

Firmware download link: http://www.dragino.com/downloads/index.php?dir=LoRa_End_Node/LSE01/Firmware/

Firmware Upgrade Method: Firmware Upgrade Instruction

2.9  Mechanical

2.10  Battery Analysis

2.10.1  Battery Type

The LDDS75 battery is a combination of a 4000mAh or 8500mAh Li/SOCI2 Battery and a Super Capacitor. The battery is non-rechargeable battery type with a low discharge rate (<2% per year). This type of battery is commonly used in IoT devices such as water meter.

The battery related documents as below:

•  Battery Dimension,

• Lithium-Thionyl Chloride Battery  datasheet,

• Lithium-ion Battery-Capacitor datasheet, Tech Spec

2.10.2  Replace the battery

3.  Configure LLDS12 via AT Command or LoRaWAN Downlink

• AT Command Connection: See FAQ.

• LoRaWAN Downlink instruction for different platforms: IoT LoRaWAN Server

•  General Commands.

• General system settings like: uplink interval.

• LoRaWAN protocol & radio related command.

•  Commands special design for LDDS75

3.1  Access AT Commands

LDDS75 supports AT Command set in the stock firmware. You can use a USB to TTL adapter to connect to LDDS75 for using AT command, as below.

Or if you have below board, use below connection:

In the PC, you need to set the serial baud rate to 9600 to access the serial console for LDDS75. LDDS75 will output system info once power on as below:

3.2  Set Transmit Interval Time

Feature: Change LoRaWAN End Node Transmit Interval.

AT Command: AT+TDC

3.3  Set Interrupt Mode

Feature, Set Interrupt mode for GPIO_EXIT.

Downlink Command: AT+INTMOD

Downlink Command: 0x06

Format: Command Code (0x06) followed by 3 bytes.

This means that the interrupt mode of the end node is set to 0x000003=3 (rising edge trigger), and the type code is 06.

• Example 1: Downlink Payload: 06000000 // Turn off interrupt mode
• Example 2: Downlink Payload: 06000003 // Set the interrupt mode to rising edge trigger

4.  FAQ

4.1  What is the frequency plan for LDDS75?

LDDS75 use the same frequency as other Dragino products. User can see the detail from this link:  Introduction

4.2  How to change the LoRa Frequency Bands/Region

You can follow the instructions for how to upgrade image.
When downloading the images, choose the required image file for download. ​

4.3  Can I use LDDS75 in condensation environment?

LDDS75 is not suitable to be used in condensation environment. Condensation on the LDDS75 probe will affect the reading and always got 0.

5.  Trouble Shooting

5.1  Why I can’t join TTN V3 in US915 / AU915 bands?

It is due to channel mapping. Please see below link:  Frequency band

5.2  AT Command input doesn't work

In the case if user can see the console output but can’t type input to the device. Please check if you already include the ENTER while sending out the command. Some serial tool doesn’t send ENTER while press the send key, user need to add ENTER in their string. 

6.  Order Info

Part Number : LDDS75-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: Battery Option

• 4 : 4000mAh battery
• 8 : 8500mAh battery

7. ​ Packing Info

Package Includes:

• LDDS75 LoRaWAN Distance Detection Sensor x 1

Dimension and weight:

• Device Size: cm
• Device Weight: g
• Package Size / pcs : cm
• Weight / pcs : g

8.  ​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.com.