Where is the Mdot-box data (temp, press,light,etc... )?

datalab · December 5, 2017, 10:01am

Hello, it is my first post:
I have installed Loraserver system, and I have connected the MDOT-BOX with MUlTECH conduit (forward mode) with LoraServer system (lora-gateway, lora-app-server,loraServer).

I have also connected mosquitto topic with the command: “mosquitto_sub -v -t “application/3/node/008000000000XXXX/rx” -v -u someuser -P somepassword”.
This command provides the following information:

“application/3/node/008000000000db13/rx {“applicationID”:“3",“applicationName”:“Lantia_App”,“deviceName”:“MDOT-BOX”,“devEUI”:“008000000000db13",“rxInfo”:[{“mac”:“00800000a000060e”,“rssi”:-24,“loRaSNR”:11.8,“name”:“00800000a000060e”,“latitude”:0,“longitude”:0,“altitude”:0}],“txInfo”:{“frequency”:868300000,“dataRate”:{“modulation”:“LORA”,“bandwidth”:125,“spreadFactor”:12},“adr”:false,“codeRate”:“4/5"},“fCnt”:206,“fPort”:1,“data”:“Dgb/DggGTPEFA24LAZ0=“}”

For each JSON generated by Mosquitto, I have decripted it with Lora-packet and got this:

decoding from Base64: Dgb/DggGTPEFA24LAZ0=
Decoded packet

      Message Type = Join Request
        PHYPayload = 0E06FF0E08064CF105036E0B019D

    ( PHYPayload = AppEUI[8] | DevEUI[8] | DevNonce[2] | MIC[4] )
            AppEUI = 05F14C06080EFF06
            DevEUI = 9D010B6E03
          DevNonce =
               MIC = 6E0B019D

application/3/node/008000000000db13/rx {“applicationID”:“3”,“applicationName”:“Lantia_App”,“deviceName”:“MDOT-BOX”,“devEUI”:“008000000000db13”,“rxInfo”:[{“mac”:“00800000a000060e”,“rssi”:-24,“loRaSNR”:8.8,“name”:“00800000a000060e”,“latitude”:0,“longitude”:0,“altitude”:0}],“txInfo”:{“frequency”:868500000,“dataRate”:{“modulation”:“LORA”,“bandwidth”:125,“spreadFactor”:12},“adr”:false,“codeRate”:“4/5”},“fCnt”:207,“fPort”:1,“data”:“Dgb/DggGTOsFA4gLAZ0=“}

decoding from Base64: Dgb/DggGTOsFA4gLAZ0=
Decoded packet

      Message Type = Join Request
        PHYPayload = 0E06FF0E08064CEB0503880B019D

    ( PHYPayload = AppEUI[8] | DevEUI[8] | DevNonce[2] | MIC[4] )
            AppEUI = 05EB4C06080EFF06
            DevEUI = 9D010B8803
          DevNonce =
               MIC = 880B019D

application/3/node/008000000000db13/rx {“applicationID”:“3",“applicationName”:“Lantia_App”,“deviceName”:“MDOT-BOX”,“devEUI”:“008000000000db13",“rxInfo”:[{“mac”:“00800000a000060e”,“rssi”:-24,“loRaSNR”:12.2,“name”:“00800000a000060e”,“latitude”:0,“longitude”:0,“altitude”:0}],“txInfo”:{“frequency”:868300000,“dataRate”:{“modulation”:“LORA”,“bandwidth”:125,“spreadFactor”:12},“adr”:false,“codeRate”:“4/5"},“fCnt”:208,“fPort”:1,“data”:“Dgb/DggGTNkFA48LAZ0=“}
decoding from Base64: Dgb/DggGTNkFA48LAZ0=
Decoded packet

      Message Type = Join Request
        PHYPayload = 0E06FF0E08064CD905038F0B019D

    ( PHYPayload = AppEUI[8] | DevEUI[8] | DevNonce[2] | MIC[4] )
            AppEUI = 05D94C06080EFF06
            DevEUI = 9D010B8F03
          DevNonce =
               MIC = 8F0B019D

All the Json messages are JoinRequest type.

I would want to get the MDOT sensor data, i. e., temperature, pression, light, gps, but I don´t know how do this.

Best regard
Antonio

brocaar · December 5, 2017, 10:50am

It is in the base64 encoded data field of the ...../rx topic. You need to decode the base64 encoded payload to bytes and then decode these based on the encoding of the mDot temperature, press ion, light, gps, … Please refer to the the MDot box documentation for the encoding of these fields.

datalab · December 5, 2017, 12:00pm

Sorry, I would like to explain it better.

This is the message I got from MDOT-BOX:

application/3/node/008000000000db13/rx {“applicationID”:“3",“applicationName”:“Lantia_App”,“deviceName”:“MDOT-BOX”,“devEUI”:“008000000000db13",“rxInfo”:[{“mac”:“00800000a000060e”,“rssi”:-24,“loRaSNR”:12.2,“name”:“00800000a000060e”,“latitude”:0,“longitude”:0,“altitude”:0}],“txInfo”:{“frequency”:868300000,“dataRate”:{“modulation”:“LORA”,“bandwidth”:125,“spreadFactor”:12},“adr”:false,“codeRate”:“4/5"},“fCnt”:208,“fPort”:1,“data”:“Dgb/DggGTNkFA48LAZ0=“}

I select the “data” field, that is: “Dgb/DggGTNkFA48LAZ0=” from “”data”:“Dgb/DggGTNkFA48LAZ0=”
and apply this decrypter “https://lorawan-packet-decoder-0ta6puiniaut.runkit.sh.”

That site returns me this:

Message Type = Join Request
AppEUI = 0500000008000000
DevEUI = 0E020B0000
DevNonce =
MIC = 000B020E

The payload always is Join Request type. Should I send a downlink message to Mdot in order to accept the connection ?

brocaar · December 5, 2017, 12:18pm

The data field is not a LoRaWAN frame. It contains the decrypted FRMPayload field of a LoRaWAN frame, thus the payload sent by your mDot. I don’t think that the https://lorawan-packet-decoder-0ta6puiniaut.runkit.sh decoder knows anything about how to decode this back to temp, gps, etc… For this you need to refer to the documentation of the mDot box.

Brenton_Gray · August 9, 2018, 9:57pm

With the mDot you configure your own data packet structure when you program it using the Mbed software.

For example in my program, after I join the network this is how I send data from a tank level sensor and battery voltage reading:

    uint16_t tank = TankPin.read_u16();
    tx_data.push_back((tank >> 8) & 0xFF);
    tx_data.push_back(tank & 0xFF);

    uint16_t battery = BatPin.read_u16();
    tx_data.push_back((battery >> 8) & 0xFF);
    tx_data.push_back(battery & 0xFF);
    logInfo("bat: %lu [0x%04X] tank: %lu [0x%04X]", battery, battery, tank, tank);

Then in Node-red to decompile this message I use:

//extract Mdot info
var raw_tank_lvl = parseInt(msg.data.substring(0,4), 16); 
var raw_battery = parseInt(msg.data.substring(4,8), 16);

//apply scaling factor, round to integer
var tank_lvl = Math.round((raw_tank_lvl-12770)/203);  //12850 = 0%, 33175 = 100%, ~203 per %     
var battery = Math.round((raw_battery/5142.58)*100); //5142.58 per volt, x 100 to round to 2 decimal places when passing ints\n\n    

//setup node-red messages
msgBat = {};
msgBat.payload = {};
msgBat.payload.value = [battery];
msgLvl = {}; 
msgLvl.payload = {};
msgLvl.payload.value = [tank_lvl];

Hope this helps

handyman · August 10, 2018, 8:35am

i have succesfuly decoded the data from the MBOX using the following functions in the:
Organizations > LoRa Server > Applications > Application configuration > Payload decoder function:

function Decode(fPort, bytes) {
var s =‘0x’;
bytes.forEach(function(byte) {
s += (‘0’ + (byte & 0xFF).toString(16)).slice(-2);
});
  string=autoCase(s);
return string;

}

function autoCase(hex){

if (hex.substr(0,2)==‘0x’){
new_hex=preatyHex(hex);
}
else {
new_hex=hex;
}
console.log(new_hex);

// console.log(new_hex.substr(0,2)==00);
// console.log(new_hex.substr(4,2)==00);

hexLength=new_hex.length;
// console.log(new_hex.substr(hexLength-2,2));

// console.log(hexLength);

if (hexLength ==28 && new_hex.substr(0,2)==‘0e’) {
console.log(‘LoraDemo’)
string=DecodeLoraDemo(new_hex);

}
else if ((new_hex.substr(0,2)==‘1d’ && new_hex.substr(hexLength-2,2)==‘1d’) && hexLength>=26) {
console.log(‘SurveySweep’)
string=DecodeSurveySweep(new_hex);
}

else if (hexLength>=22 && (new_hex.substr(0,2)==‘00’ && new_hex.substr(4,2)==‘00’)){
console.log(‘SurveyGPS’)
  // new_hex=new_hex+'00000000000000000000';
  string=DecodeSurveyGPS(new_hex);
}

return string;
}

function DecodeLoraDemo(hex){

var xAc=parseInt(hex.substr(2,2),16)*0.0625;
var yAc=parseInt(hex.substr(4,2),16)*0.0625;
var zAc=parseInt(hex.substr(6,2),16)*0.0625;
var presure=parseInt(hex.substr(10,6),16)*0.25/1000;
var lux=parseInt(hex.substr(18,4),16)*0.25;
var temperature=parseInt(hex.substr(24,4),16)*0.0625;

return {“acceleration_X”:xAc, “acceleration_Y”:yAc, “acceleration_Z”:zAc, “presure”:presure, “lux”:lux,“temperature”:temperature}
}

function DecodeSurveyGPS(hex){

var temperature=parseInt(hex.substr(2,2),16);
var lat=parseInt(hex.substr(6,8),16)/(Math.pow(2,31)-1)*90;
var long=parseInt(hex.substr(14,8),16)/(Math.pow(2,31)-1)*180;

if (long > 180) {
long=(360-long)*(-1)
}
return {“temperature”:temperature, “LatitudeGPS”:lat, “LongitudeGPS”:long}
}

function DecodeSurveySweep (hex){

var QosUpLink = hex.substr(2,10); //4 bytes
var NumberOfGateways = parseInt(QosUpLink.substr(2,4),16);
var Margin=parseInt(QosUpLink.substr(6,2),16);
var TxPower=parseInt(QosUpLink.substr(8,2),16);

var QosDownLink = hex.substr(12,8); //3 bytes
var RSSI=parseInt(QosDownLink.substr(2,4),16);
var SNR=parseInt(QosDownLink.substr(6,2),16);

var LockStatus =parseInt(hex.substr(22,2),16).toString(2); //1 byte
var gpsStatus=checkgpsStatus(LockStatus.substr(0,4));
var numberOfSatelit = parseInt(LockStatus.substr(4,4),2);

var LatitudeGPS = hex.substr(24,10); //4 bytes
var LongitudeGPS =hex.substr(34,12); //5 bytes

return {“10_qosUpLink”: QosUpLink,
“11_numberOfGateways”: NumberOfGateways,
“12_margin”: Margin,
“13_txPower”: TxPower,
“20_qosDownLink”: QosDownLink,
“21_rSSI”: RSSI,
“22_SNR”: SNR,
“30_LockStatus”: LockStatus,
“31_gpsStatus”: gpsStatus,
“32_numberOfSatelit”: numberOfSatelit,
“40_LatitudeGPS”: LatitudeGPS,
“50_LongitudeGPS”: LongitudeGPS}
}

function checkgpsStatus(byteString){
/**
0 No GPS device detected.
1 No fix
2 2D fix – only latitude, longitude, and time are valid
3 3D fix – all data valid

ex: 1100
**/

resultat=‘’;

if (byteString.substr(0,1)==0){
resultat += 'No GPS device detected, ';
}
else if (byteString.substr(0,1)==1){
resultat += 'GPS device detected, ';
}

if (byteString.substr(1,1)==1){
resultat += 'No Fix ';
}
else if (byteString.substr(2,1)==1) {
resultat += '2DFix ';
}
else if (byteString.substr(3,1)==1) {
resultat += '3DFix ';
}

return resultat;
}

function preatyHex(hex){
if (hex.substr(0,2)==‘0x’){
hex=hex.substr(2,hex.length);
}
return hex;
}

best regards

bdbuysse · January 2, 2019, 1:19am

Hi…

I tried the above but had issues getting it to work with my mbox (2…1.2) and loraserver (2.4.1). It kept throwing a an error about defining the var s variable.

I was however to get decode my mbox using the following code, so thought I’d share back with the community.

// Decode decodes an array of bytes into an object.
//  - fPort contains the LoRaWAN fPort number
//  - bytes is an array of bytes, e.g. [225, 230, 255, 0]
// The function must return an object, e.g. {"temperature": 22.5}

function Decode(fPort, bytes) {
var evb_sensors = {};
var EVB_TYPE = {
  none: 0,
  led_1: 1,
  led_2: 2,
  lux_max: 3,
  lux_min: 4,
  lux: 5,
  barometer_max: 6,
  barometer_min: 7,
  barometer: 8,
  temperature_max: 9,
  temperature__min: 10,
  temperature: 11,
  accelerometer_max: 12,
  accelerometer_min: 13,
  accelerometer: 14,
  tx_interval: 15,
  amps_max: 16,
  amps_min: 17,
  amps: 18,
  m2x_device: 19,
  m2x_key: 20,
};

/*
 * Process the EVB LoRa payload.
 *
 * EVB payload contains one or more TLV fields.
 *
 * [<type: accelerometer><length: 6><x-high><x-low><y-high><y-low><z-high><z-low>]
 * [<type: barometer><length: 3><byte2><byte1><byte0>]
 * [<type: temperature><length: 2><byte-high><byte-low>]
 * 
 */
for (var index = 0; index < bytes.length; ) {
  var type = bytes[index++];
//   var length = bytes[index++];
  var value;
  console.log("type: " + type + " length: " );

  switch (type) {
  case EVB_TYPE.lux:
    if (typeof(evb_sensors.light) == "undefined") {
      evb_sensors.light = {};
    }

    value = bytes[index++] << 8;
    value |= bytes[index++];
    value = value * 0.24;

    evb_sensors.light.lux = value;
    break;
  case EVB_TYPE.barometer:
    if (typeof(evb_sensors.barometer) == "undefined") {
      evb_sensors.barometer = {};
    }

    value = bytes[index++] << 16;
    value |= bytes[index++] << 8;
    value |= bytes[index++];
    value = value * 0.00025;

    evb_sensors.barometer.pa = value;
    break;
  case EVB_TYPE.temperature:
    if (typeof(evb_sensors.temperature) == "undefined") {
    evb_sensors.temperature = {};
      }

    value = (bytes[index++] << 24) >> 16;
    value |= bytes[index++];
    value = value * 0.0625;

    evb_sensors.temperature.c = value;
    evb_sensors.temperature.f =  value * 9 / 5 + 32; 
      
      break;
  case EVB_TYPE.accelerometer:
    if (typeof(evb_sensors.accelerometer) == "undefined") {
    evb_sensors.accelerometer = {};
      }
      // evb_sensors.accelerometer.x = (bytes[index++] << 24) >> 16;
      var x1 = evb_sensors.accelerometer.x = bytes[index++] ;
      // x1 = ~x1 ; 
      // x1 = ( x1 + 1 ) % 256; 
      evb_sensors.accelerometer.x = x1 * 0.0625//; / 15;
      // evb_sensors.accelerometer.y = (bytes[index++] << 24) >> 16;
      var y1 = evb_sensors.accelerometer.y = bytes[index++] ;
      // y1 = ~ y1 ; 
      // y1 = ( y1 + 1 ) % 256;
        
      var y1 = evb_sensors.accelerometer.y = y1 * 0.0625 ; // / 15 ;

        // evb_sensors.accelerometer.z = (bytes[index++] << 24) >> 16;
      var z1 = evb_sensors.accelerometer.z = bytes[index++] ;
      // z1 = ~ z1 ; 
      // z1 = ( z1 + 1 ) % 256; 
      // z1 = z1 - 128;
      var z1 = evb_sensors.accelerometer.z = z1 * 0.0625; // / 15;
      break;      
      }
  }
  return {
    temp_c: evb_sensors.temperature.c,
    temp_f: evb_sensors.temperature.f,
    moisture: evb_sensors.barometer.pa,
    lux: evb_sensors.light.lux,
    x_acc: evb_sensors.accelerometer.x,
    y_acc: evb_sensors.accelerometer.y,
    z_acc: evb_sensors.accelerometer.z
  }
}

brocaar · January 2, 2019, 8:20am

Please format your code the next time (I’ve edited your post for JS highlighting)

Where is the Mdot-box data (temp, press,light,etc... )?

decoding from Base64: Dgb/DggGTPEFA24LAZ0= Decoded packet

decoding from Base64: Dgb/DggGTOsFA4gLAZ0= Decoded packet

decoding from Base64: Dgb/DggGTPEFA24LAZ0=
Decoded packet

decoding from Base64: Dgb/DggGTOsFA4gLAZ0=
Decoded packet