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lora-devices-ttn

pFlow - E3R

The E3R is a LoRaWAN Ultrasonic Heat Flow Meter.

Table of contents

  1. Specifications
  2. Documents
  3. tbd
  4. Ordering Info
  5. Settings (mandatory!)
  6. Payload Decoder

Specifications

  • indoor device
  • Price ca. CHF 350.- (03.06.2025)
  • Built-in sensors
    • Water Flow, [m3/h]
  • Pipe size range: DN20,DN25,DN32,DN40,DN50,DN65,DN80
  • Power Supply: 10-36 VDC/500mA
  • LoRaWAN version: 1.0.2
  • LoRaWAN device class: C
  • Modbus as well available

Documents

  • tbd

Ordering Info

  • tbd

Settings (mandatory!)

  1. On the device, go to Device Settings / 3. Communication / 4. Lora USC and set it to 868100000 Hz
    • you can enter the Device Settings by pressing the button with the three lines on the device
  2. Make shure, that in ttn Device Class C is configured under Network layer
  3. Reset Lora (in Device Settings / 3. Communication / 8. Reset Lora)
  4. Mount the device on the pipe
    • use a lot of ultrasonic contact gel on the ultrasonic contacts
    • mount as well the temperature sensors with thermal paste
  5. Set the pipe Diameter, Wall Thickness and Pipe Material (in Device Settings / 1. Pipe Parameter)
    • the thickness could also be measured with a separate ultrasonic thickness sensor
  6. Stop the water flow in the hydraulic circuit and make a zero set (in Device Settings / 5. Select Setting / 4. Reset Zero)
  7. Start the water flow, done
  8. If possible (recommended):
    • Make a paralell measurement with a high quality ultrasonic flow meter
    • Calculate the correction factor and set it in the device (in Device Settings / 6. Calibration / 1. Scale Factor)

Payload Decoder

function decodeUplink(input) {
    var bytes = input.bytes;
    var fPort = input.fPort;
    
    var decoded = {};

    // Uplink payload decoding
    decoded.uplink = readUplinkInfo(bytes);
    
    return {
        data: decoded
    };
}

function readUplinkInfo(bytes) {
    var uplink = {};
    
    uplink["volumeFlow_m3perh_abs"] = readUInt32(0, bytes) / 100;
    uplink["volume_m3_inc"] = readUInt32(4, bytes) / 100;
    uplink["energy_kWh_inc@heating"] = readUInt32(13,bytes) /100;
    uplink["energy_kWh_inc@cooling"] = readUInt32(19,bytes) / 100;
    uplink["temperature_degrC_abs@return"] = readUInt16(11,bytes) / 100;
    uplink["temperature_degrC_abs@flow"] = readUInt16(17,bytes) / 100;
    uplink["velocity_mpers_abs"] = readUInt16(8, bytes) / 100;
    uplink["signalQuality_perc_abs"] = readUInt8(10, bytes);

    return uplink;
}

// helper functions

function readUInt32(index, bytes) {
    var value = (bytes[index] << 24 & 0xff000000) | (bytes[index + 1] << 16 & 0x00ff0000)  | (bytes[index + 2] << 8 & 0x0000ff00) | (bytes[index + 3] & 0x000000ff);
    return value & 0xffffffff;
}

function readUInt16(index, bytes) {
    var value = ((bytes[index] << 8) & 0xff00) | ((bytes[index + 1]) & 0x00ff);
    return value & 0xffff;
}

function readUInt8(index, bytes) {
    var value = ((bytes[index]) & 0xff);
    return value & 0xff;
}