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lora-devices-ttn

Dragino - LSN50v2-D23

The LSN50v2-D23 is a LoRaWAN Waterproof Outdoor Temperature Sensor with 3 external Probes.

Table of contents

  1. Specifications
  2. Documents/Links
  3. Ordering Info
  4. Device specific Information
    1. Switch on the device
    2. Channel Mapping
  5. Adding the Device to TTN
  6. Optional Settings
    1. Change sampling interval
      1. Examples
  7. Payload Decoder

Specifications

  • indoor/outdoor device
  • Price ca. CHF 70.- (09.08.2023)
  • 3 External Sensors
    • Temperature, -55 … +125 [°C], ± 0.5 (max ±2.0 °C)
  • Power Supply: 1 built in 8500mAh Li-SOCI2 battery
    • Expected life time: depending on usage, 5 … 10 years
  • LoRaWAN version: 1.0.3
  • LoRaWAN device class: A
  • Protection: IP66
  • Operating Temperature: -40 … 85°C
  • Size: 124 × 63 × 42 mm
  • Weight: 295 g

Ordering Info

Device specific Information

Switch on the device

Out of the factory the device is switched off. To power on the LSN50v2-D20, open the case and set the jumper (connect the two pins):

Switching between active and sleep mode (switch off / on, reset)

Channel Mapping

  • Channel 1: Red
  • Channel 2: White
  • Channel 3: Black

Adding the Device to TTN

  • The JoinEUI, App EUI and the DevEUI should be on a sticker on the cardboard box.
  • Before a device can communicate via “The Things Network” we have to add it to an application.
  1. Create a new application
  2. Under End devices in the application click (+) Register end device
  3. Under Input method select Enter end device specifics manually
  4. Under Frequency plan select Europe 863-870 Mhz (SF9 for RX2 - recommended)
  5. Under LoRaWAN version select 1.0.3
  6. Under JoinEUI enter the App EUI from the App and press Confirm
  7. Enter as well the DevEUI and the AppKey from the App
  8. Set an end-device name
  9. Press Register end device
  10. Add the payload formatter from below, either to the device itself or if all devices in the app are from the same type, to the application
  11. Switch on the device
  12. Close the case
  • After Configuration, the device restarts automatically and tries to join the network
  • Now the device should join the network and you can see the incoming telegrams in the Live data section

Optional Settings

Change sampling interval

To change the sampling interval, you have to send the device configuration telegrams (Downlink-Messages) The time interval in minutes at which the sensor queries the current values.

  1. In the TTN Console on the device view, select the device and change to the tab Messaging, select Downlink
  2. Change the FPort to 2
  3. Copy/paste the payload, e.g. 01000258 into the Payload field to set interval to 10 minutes
  4. Press Send
  5. In the Data tab you should now see the scheduled telegram. The device only receives downlink data after a transmission. Therefore start a transmission by pressing the button on the back of the sensor (push once short, green led will illuminate)

Examples

‘0100’ is an identifier, the rest represents the sampling interval in hex

  • 5 Minutes Interval: ‘0100012C’ (300s in hex are ‘012C’)
  • 10 Minutes Interval: ‘01000258’ (600s in hex are ‘0258’)
  • 15 Minutes Interval: ‘01000384’ (900s in hex are ‘0384’)
  • 60 Minutes Interval: ‘01000E10’ (3600s in hex are ‘0E10’)

Payload Decoder

function decodeUplink(input) {
  var port = input.fPort;
  var bytes = input.bytes;
  var mode = (bytes[6] & 0x7C) >> 2;
  var data = {};

  switch (port) {
    case 2:
      if (mode == '3') {
        data.battery_volt = (bytes[0] << 8 | bytes[1]) / 1000;
        data.alarm_state = (bytes[6] & 0x01) ? 1 : 0;

        if ((bytes[2] == 0xff) && (bytes[3] == 0xff)) {
          data["temperature_degrC@channel1"] = 32767.0;
        } else {
          data["temperature_degrC@channel1"] = parseFloat(((bytes[2] << 24 >> 16 | bytes[3]) / 10).toFixed(1));
        }

        if ((bytes[7] == 0xff) && (bytes[8] == 0xff)) {
          data["temperature_degrC@channel2"] = 32767.0;
        } else {
          data["temperature_degrC@channel2"] = parseFloat(((bytes[7] << 24 >> 16 | bytes[8]) / 10).toFixed(1));
        }

        if ((bytes[9] == 0xff) && (bytes[10] == 0xff)) {
          data["temperature_degrC@channel3"] = 32767.0;
        } else {
          data["temperature_degrC@channel3"] = parseFloat(((bytes[9] << 24 >> 16 | bytes[10]) / 10).toFixed(1));
        }
      }

      if (bytes.length == 11) {
        return {
          data: data,
        };
      }
      break;

    default:
      return {
        errors: ["unknown FPort"]
      };
  }
}