jooby-codec v4.1.0

Jooby message encoders/decoders

This library contains message encoders and decoders for Jooby LoRaWAN devices.

Installation

Install required dependencies:

npm install jooby-codec

This will provide 2 protocols of codecs:

• Analog
• MTX

Usage of Analog codecs

Add to the project:

import {commands, message} from 'jooby-codec/analog';

// output all available downlink and uplink commands tree
console.log(commands);
// all uplink commands
console.log(commands.uplink);
// one particular command
console.log(commands.uplink.correctTime2000);

// output main namespace for work with messages
console.log(message);

But it's better to add only necessary commands to the project:

// to get only downlink commands
import {downlink} from 'jooby-codec/analog/commands';
// or slightly more efficient
import * as downlink from 'jooby-codec/analog/commands/downlink';

// to get one particular command
import * as setTime2000 from 'jooby-codec/analog/commands/downlink/setTime2000.js';

The last approach is preferred as it is more efficient and will init only a necessary commands.

Prepare and parse downlink message:

import * as message from 'jooby-codec/analog/message/downlink';
import * as downlinkCommands from 'jooby-codec/analog/commands/downlink';
import getHexFromBytes from 'jooby-codec/utils/getHexFromBytes.js';

const commands = [
    {
        id: downlinkCommands.correctTime2000.id,
        parameters: {sequenceNumber: 45, seconds: -120}
    }
];
const bytes = message.toBytes(commands);

console.log('message encoded:', JSON.stringify(bytes));
// output:
'[12,2,45,136,254]'

console.log('message encoded in HEX:', getHexFromBytes(bytes));
// output:
'0c 02 2d 88 fe'

// decode message back from bytes
const parsedMessage = message.fromBytes(bytes);

console.log('parsedMessage:', parsedMessage);
// output:
{
    commands: [
      {
        id: 12,
        name: 'correctTime2000',
        headerSize: 2,
        bytes: [Array],
        parameters: [Object]
      }
    ],
    bytes: [ 12, 2, 45, 136, 254 ],
    lrc: { expected: 254, actual: 254 }
}

Parse uplink message:

import * as message from 'jooby-codec/analog/message/uplink';

// binary data received from a device
const bytes = [0x0c, 0x01, 0x00, 0x58];

// decode it
const payload = message.fromBytes(bytes);

if ( 'error' in payload ) {
    console.log('decode failure:', payload.error, payload.message);
} else {
    console.log('message decoded:', payload.commands);
    // output:
    [
        {
            id: 12,
            headerSize: 2,
            bytes: [ 12, 1, 0 ],
            parameters: { status: 0 }
        }
    ]
}

Usage of MTX codecs

Add to the project:

import {commands, message} from 'jooby-codec/mtx';

// output all available downlink and uplink commands tree
console.log(commands);
// all uplink commands
console.log(commands.uplink);
// one particular command
console.log(commands.uplink.setDateTime);

// output main namespace for work with messages
console.log(message);

But it's better to add only necessary commands to the project:

// to get only downlink commands
import {downlink} from 'jooby-codec/mtx/commands';
// or slightly more efficient
import * as downlink from 'jooby-codec/mtx/commands/downlink';

// to get one particular command
import * as setDateTime from 'jooby-codec/mtx/commands/downlink/setDateTime.js';

The last approach is preferred as it is more efficient and will init only a necessary commands.

Prepare and parse downlink message and frame:

import * as message from 'jooby-codec/mtx/message/downlink';
import * as downlinkCommands from 'jooby-codec/mtx/commands/downlink';
import getHexFromBytes from 'jooby-codec/utils/getHexFromBytes.js';
import * as frameTypes from 'jooby-codec/mtx/constants/frameTypes.js';

const aesKey = [...Array(16).keys()];
const messageId = 10;

const commands = [
    {
        id: downlinkCommands.setDateTime.id,
        parameters: {
            isSummerTime: false,
            seconds: 55,
            minutes: 31,
            hours: 18,
            day: 2,
            date: 19,
            month: 2,
            year: 24
        }
    }
];
const bytes = message.toBytes(
    commands,
    {
        messageId,
        accessLevel: downlinkCommands.setDateTime.accessLevel,
        aesKey
    }
);

console.log('message encoded:', JSON.stringify(bytes));
// output:
[10,19,237,116,10,174,74,186,200,66,196,27,231,245,13,60,40,132]

console.log('message encoded in HEX:', getHexFromBytes(bytes));
// output:
'0a 13 ed 74 0a ae 4a ba c8 42 c4 1b e7 f5 0d 3c 28 84'


const frameBytes = message.toFrame(
    bytes,
    {
        type: frameTypes.DATA_REQUEST,
        source: 0xffff,
        destination: 0xaaaa
    }
);

console.log('frame encoded:', frameBytes);
// output:
[126,80,170,170,255,255,10,125,51,237,116,10,174,74,186,200,66,196,27,231,245,13,60,40,132,97,187,126]

console.log('frame encoded in HEX:', getHexFromBytes(frameBytes));
// output:
'7e 50 aa aa ff ff 0a 7d 33 ed 74 0a ae 4a ba c8 42 c4 1b e7 f5 0d 3c 28 84 61 bb 7e'


// decode message back from bytes
const parsedMessage = message.fromBytes(bytes, {aesKey});

console.log('parsed message:', parsedMessage);
// output:
{
    messageId: 3,
    accessLevel: 3,
    commands: [
      {
        id: 8,
        name: 'setDateTime',
        headerSize: 2,
        bytes: [Array],
        parameters: [Object]
      }
    ],
    bytes: [
        3,  19, 237, 116,  10, 174,
       74, 186, 200,  66, 196,  27,
      231, 245,  13,  60,  40, 132
    ],
    lrc: { expected: 119, actual: 119 }
}

// decode message back from frame
const parsedFrame = message.fromFrame(frameBytes, {aesKey});

console.log('parsed frame:', parsedFrame);
// output:
{
    type: 80,
    destination: 43690,
    source: 65535,
    messageId: 10,
    accessLevel: 3,
    commands: [
      {
        id: 8,
        name: 'setDateTime',
        headerSize: 2,
        bytes: [Array],
        parameters: [Object]
      }
    ],
    bytes: [
       10,  19, 237, 116,  10, 174,
       74, 186, 200,  66, 196,  27,
      231, 245,  13,  60,  40, 132
    ],
    lrc: { expected: 119, actual: 119 },
    crc: 25019
}

Parse uplink message:

import * as message from 'jooby-codec/mtx/message/uplink';
import getBytesFromHex from 'jooby-codec/utils/getBytesFromHex.js';

const aesKey = [...Array(16).keys()];

const messageBytes = getBytesFromHex('0a 13 9b 4b f7 2a d1 e5 49 a5 09 50 9a 59 7e c2 b5 88');
const frameBytes = getBytesFromHex('7e 51 aa aa ff ff 0a 7d 33 9b 4b f7 2a d1 e5 49 a5 09 50 9a 59 7d 5e c2 b5 88 21 54 7e');

const parsedMessage = message.fromBytes(messageBytes, {aesKey});

console.log('parsed message:', parsedMessage);
// output:
{
    messageId: 10,
    accessLevel: 3,
    commands: [
      {
        id: 112,
        name: 'getBuildVersion',
        headerSize: 2,
        bytes: [Array],
        parameters: [Object]
      }
    ],
    bytes: [
       10,  19, 155,  75, 247,  42,
      209, 229,  73, 165,   9,  80,
      154,  89, 126, 194, 181, 136
    ],
    lrc: { expected: 53, actual: 53 }
}

const parsedFrame = message.fromFrame(frameBytes, {aesKey});

console.log('parsed frame:', parsedFrame);
// output:
{
    type: 81,
    destination: 43690,
    source: 65535,
    messageId: 10,
    accessLevel: 3,
    commands: [
      {
        id: 112,
        name: 'getBuildVersion',
        headerSize: 2,
        bytes: [Array],
        parameters: [Object]
      }
    ],
    bytes: [
       10,  19, 155,  75, 247,  42,
      209, 229,  73, 165,   9,  80,
      154,  89, 126, 194, 181, 136
    ],
    lrc: { expected: 53, actual: 53 },
    crc: 8532
}