wifi.js

"use strict";

var net = require( 'net' );
var util = require( "util" );
var events = require( 'events' );

function Wifi ( host, pin, port, model ) {
    this.host = host;
    this.pin = pin;
    this.port = (typeof port === "undefined") ? 8068 : port;
    this.model = (typeof model === "undefined") ? null : model;
    events.EventEmitter.call( this );
}

util.inherits( Wifi, events.EventEmitter );

var crc16 = function ( buf ) {
    // Thanks to http://code.google.com/p/heatmiser-wifi/ for the algorithm
    // Process 4 bits of data
    var crc16_4bits = function ( crc, nibble ) {
        var lookup = [ 0x0000, 0x1021, 0x2042, 0x3063,
            0x4084, 0x50A5, 0x60C6, 0x70E7,
            0x8108, 0x9129, 0xA14A, 0xB16B,
            0xC18C, 0xD1AD, 0xE1CE, 0xF1EF ];
        return ((crc << 4) & 0xffff) ^ lookup[ (crc >> 12) ^ nibble ];
    }

    // Process the whole message
    var crc = 0xffff;
    for ( var i = 0; i < buf.length; i++ ) {
        crc = crc16_4bits( crc, buf[ i ] >> 4 );
        crc = crc16_4bits( crc, buf[ i ] & 0x0f );
    }

    // Return the CRC
    return crc;
}

var parse_dcb = function ( dcb_buf ) {
    var model = [ 'DT', 'DT-E', 'PRT', 'PRT-E', 'PRTHW' ][ dcb_buf.readUInt8( 4 ) ];
    var version = dcb_buf.readUInt8( 3 );
    var length = dcb_buf.readUInt16LE( 0 );
    if ( length != dcb_buf.length ) throw "Incorrect DCB length";
    if ( model !== 'PRTHW' ) version &= 0x7F;
    var program_mode = [ '5/2', '7' ][ dcb_buf.readUInt8( 16 ) ];

    return {
        length: length,
        vendor_id: [ 'HEATMISER', 'OEM' ][ dcb_buf.readUInt8( 2 ) ],
        model: model,
        version: version / 10,
        temp_format: [ 'C', 'F' ][ dcb_buf.readUInt8( 5 ) ],
        switch_differential: dcb_buf.readUInt8( 6 ) / 2,
        frost_protection: !!dcb_buf.readUInt8( 7 ),
        calibration_offset: dcb_buf.readUInt16LE( 8 ),
        output_delay: dcb_buf.readUInt8( 10 ),
        up_down_key_limit: dcb_buf.readUInt8( 11 ),
        sensor_selection: [ 'built_in_only', 'remote_only', 'floor_only', 'built_in+floor', 'remote+floor' ][ dcb_buf.readUInt8( 13 ) ],
        optimum_start: dcb_buf.readUInt8( 14 ),
        rate_of_change: dcb_buf.readUInt8( 15 ),
        program_mode: program_mode,
        frost_protect_temp: dcb_buf.readUInt8( 17 ),
        set_room_temp: dcb_buf.readUInt8( 18 ),
        floor_max_limit: dcb_buf.readUInt8( 19 ),
        floor_max_limit_enabled: !!dcb_buf.readUInt8( 20 ),
        device_on: !!dcb_buf.readUInt8( 21 ),
        key_lock: !!dcb_buf.readUInt8( 22 ),
        run_mode: [ 'heating', 'frost_protection' ][ dcb_buf.readUInt8( 23 ) ],
        away_mode: !!dcb_buf.readUInt8( 24 ),
        holiday_enabled: !!dcb_buf.readUInt8( 30 ),
        holiday_return_date: {},
        temp_hold_minutes: dcb_buf.readUInt16LE( 31 ),
        remote_air_temp: dcb_buf.readUInt16LE( 33 ) === 0xFFFF ? null : dcb_buf.readUInt16LE( 33 ) / 10,
        floor_temp: dcb_buf.readUInt16LE( 35 ) === 0xFFFF ? null : dcb_buf.readUInt16LE( 35 ) / 10,
        built_in_air_temp: dcb_buf.readUInt16LE( 37 ) === 0xFFFF ? null : dcb_buf.readUInt16LE( 37 ) / 10,
        error_code: dcb_buf.readUInt8( 39 ),
        heating_on: !!dcb_buf.readUInt8( 40 ),
        boost_in_min: dcb_buf.readUInt16LE( 41 ),
        hot_water_on: !!((model == 'PRTHW') ? dcb_buf.readUInt8( 43 ) : false),
        current_time: extract_date( dcb_buf, model ),
    }
}

var extract_date = function ( dcb_buf, model ) {
    var offset = (model == 'PRTHW') ? 3 : 0
    return new Date( 2000 + dcb_buf.readUInt8( 41 + offset ), dcb_buf.readUInt8( 42 + offset ) - 1, dcb_buf.readUInt8( 43 + offset ), dcb_buf.readUInt8( 45 + offset ), dcb_buf.readUInt8( 46 + offset ), dcb_buf.readUInt8( 47 + offset ) )
}

var parse_response = function ( response ) {
    var code = response.readUInt8( 0 );
    if ( code != 0x94 ) throw "Invalid return code";
    var frame_len = response.readUInt16LE( 1 );
    if ( frame_len != response.length ) throw "Incorrect packet length";
    var crc = response.readUInt16LE( frame_len - 2 );
    var calc_crc = crc16( response.slice( 0, frame_len - 2 ) );
    if ( crc != calc_crc ) throw "Incorrect CRC";

    return {
        code: code,
        frame_len: frame_len,
        crc: crc,
        start_addr: response.readUInt16LE( 3 ),
        num_bytes: response.readUInt16LE( 5 ),
        dcb: parse_dcb( response.slice( 7, frame_len - 2 ) )
    }
}

// Construct an arbitrary thermostat command
Wifi.prototype.command = function ( operation, data, callback ) {
    var len = 7 + data.length;
    var buf = new Buffer( 5 + data.length + 2 );
    buf.writeUInt8( operation, 0 ); // 0
    buf.writeUInt16LE( len, 1 ); // 1-2
    buf.writeUInt16LE( this.pin, 3 ); // 3-4
    data.copy( buf, 5 );
    var crc = crc16( buf.slice( 0, buf.length - 2 ) );
    buf.writeUInt16LE( crc, buf.length - 2 ); // last 2 bytes

    var client = net.connect( { host: this.host, port: this.port }, function () { //'connect' listener
        client.write( buf );
    } );

    client.setTimeout( 3000 );
    client.on( 'data', function ( data ) {
        var obj = parse_response( data );
        this.model = obj.dcb.model;
        // if callback is set don't emit an event
        if ( typeof callback === 'undefined' ) {
            this.emit( 'success', obj );
        }
        else {
            callback( obj );
        }
        client.end();
    }.bind( this ) );
    client.on( 'timeout', function ( e ) {
        client.end();
        this.emit( 'error', (typeof e === 'undefined') ? new Error( "Timed out" ) : e );
    }.bind( this ) );
    client.on( 'error', function ( e ) {
        client.end();
        this.emit( 'error', e );
    }.bind( this ) );
}

Wifi.prototype.read_device = function ( callback ) {
    this.info( callback );
}

Wifi.prototype.info = function ( callback ) {
    this.command( 0x93, new Buffer( [ 0x00, 0x00, 0xFF, 0xFF ] ), callback );
}

Wifi.prototype.write_device = function ( data ) {
    var self = this;

    var do_write = function ( items ) {
        var buf = Buffer.concat( items );
        // First byte to send is the number of items
        var buffer = new Buffer( buf.length + 1 );
        buffer[ 0 ] = items.length;
        buf.copy( buffer, 1 );

        self.command( 0xa3, buffer );
    }

    if ( this.model == null ) {
        this.read_device( function () {
            try {
                status_to_dcb( this.model, data, do_write );
            }
            catch ( e ) {
                this.emit( 'error', e );
            }
        } );
    }
    else {
        try {
            status_to_dcb( this.model, data, do_write );
        }
        catch ( e ) {
            this.emit( 'error', e );
        }
    }
}

var dcb_entry = function ( position, data ) {
    var l = (typeof data === 'number') ? 1 : data.length
    var buf = new Buffer( 2 + 1 + l ); // position, length, data
    buf.writeUInt16LE( position, 0 );
    buf.writeUInt8( l, 2 );
    if ( typeof data === 'number' ) {
        if ( data % 1 == 0 ) {
            // integer
            buf.writeUInt8( data, 3 );
        }
        else {
            // float, wrong type
            throw "Float value not valid, must be integer: " + data;
        }
    }
    else {
        data.copy( buf, 3 );
    }
    return buf;
}

var timeToByteBuffer = function ( hours, minutes ) {
    var buf = new Buffer( 2 );
    buf[ 0 ] = hours;
    buf[ 1 ] = minutes;
    return buf;
}

var dateTimeToByteBuffer = function ( datetime ) {
    var buf = new Buffer( 7 );
    var i = 0;
    buf[ i++ ] = datetime.getFullYear() - 2000;
    buf[ i++ ] = datetime.getMonth() + 1;
    buf[ i++ ] = datetime.getDate();
    var day = datetime.getDay();
    buf[ i++ ] = day == 0 ? 7 : day; // 0 Sunday -> 7
    buf[ i++ ] = datetime.getHours();
    buf[ i++ ] = datetime.getMinutes();
    buf[ i++ ] = datetime.getSeconds();
    return buf;
}

var status_to_dcb = function ( model, data, callback ) {
    var items = [];

    var keys = Object.keys( data );
    for ( var i = 0; i < keys.length; i++ ) {
        var key = keys[ i ];
        switch ( key ) {
            case 'time':
                // Current date and time, from a javascript Date object
                items.push( dcb_entry( 43, dateTimeToByteBuffer( data[ key ] ) ) );
                break;
            case 'enabled':
                // General operating status (on/off)
                items.push( dcb_entry( 21, data[ key ] ? 1 : 0 ) );
                break;
            case 'keylock':
                // General operating status (on/off)
                items.push( dcb_entry( 22, data[ key ] ? 1 : 0 ) );
                break;
            case 'holiday':
                // holiday mode
                //   { enabled: false }
                //   { enabled: true, time: new Date() }
                if ( ('enabled' in data[ key ]) && !data[ key ][ 'enabled' ] ) {
                    // Cancel holiday mode
                    items.push( dcb_entry( 24, 0 ) );
                }
                else if ( 'time' in data[ key ] ) {
                    // Set return date and time, date without seconds
                    data[ 24 ] = dateTimeToByteBuffer( data[ key ][ 'time' ] ).slice( 0, 5 );
                }
                break;
            case 'runmode':
            case 'run_mode':
                // Run mode (controls heating)
                if ( model != 'TM1' ) {
                    var frost = false
                    switch ( data[ key ] ) {
                        case 'frost':
                        case 'frost_protection':
                            frost = true
                            break;
                        case 'heating':
                            frost = false
                            break;
                        default:
                            throw "run_mode not valid [heating, frost_protection]: " + data[ key ]
                    }
                    items.push( dcb_entry( 23, frost ? 1 : 0 ) );
                }
                break;
            case 'awaymode':
            case 'away_mode':
                // Away mode (controls hot water) [true, false]
                if ( model.match( /(HW|TM1)$/ ) ) {
                    var away = (typeof data[ key ] == 'boolean') ? data[ key ] : data[ key ] == 'away'
                    items.push( dcb_entry( 31, away ? 1 : 0 ) );
                }
                break;
            case 'frostprotect':
                // Frost protection (temperature only, cannot disable)
                if ( 'target' in data[ key ] ) {
                    items.push( dcb_entry( 17, data[ key ][ 'target' ] ) );
                }
                break;
            case 'floorlimit':
                // Floor limit (temperature only, cannot disable)
                if ( model.match( /-E$/ ) && ('floormax' in data[ key ]) ) {
                    items.push( dcb_entry( 19, data[ key ][ 'floormax' ] ) );
                }
                break;
            case 'heating':
                // Status of heating (target and hold - in minutes - only, cannot turn on/off)
                if ( model != 'TM1' ) {
                    if ( 'target' in data[ key ] ) {
                        items.push( dcb_entry( 18, data[ key ][ 'target' ] ) );
                    }
                    if ( 'hold' in data[ key ] ) {
                        var buf = new Buffer( 2 );
                        buf.writeUInt16LE( data[ key ][ 'hold' ], 0 );
                        items.push( dcb_entry( 32, buf ) );
                    }
                }
                break;
            case 'hotwater':
                // Status of hot water (values are different from those read)
                if ( model.match( /(HW|TM1)$/ ) ) {
                    if ( 'boost' in data[ key ] ) {
                        var buf = new Buffer( 2 );
                        buf.writeUInt16LE( data[ key ][ 'boost' ], 0 );
                        items.push( dcb_entry( 25, buf ) );
                    }
                    if ( 'on' in data[ key ] ) {
                        items.push( dcb_entry( 42, data[ key ][ 'on' ] ? 1 : 2 ) );
                    }
                    else {
                        items.push( dcb_entry( 42, 0 ) );
                    }
                }
                break;
            case 'comfort':
                // Heating comfort levels program
                if ( model.match( /^PRT/ ) ) {
                    var days = data[ key ].length
                    var days_expected = status.config.progmode == '5/2' ? 2 : 7
                    if ( days != days_expected ) {
                        throw "Incorrect number of days specified for comfort levels program " + days + ". Expected " + days_expected;
                    }
                    for ( var day = 0; day < days; day++ ) {
                        var comfort;
                        for ( var entry = 0; entry < 4; entry++ ) {
                            var row = data[ key ][ day ][ entry ];
                            comfort.concat( typeof row !== "undefined" ? timeToByteBuffer( row[ 'time' ] ).push( row[ 'target' ] ) : new Buffer( [ 24, 0, 16 ] ) );
                            var new_schedule = new Buffer( [ 24, 0, 16 ] ); // default disabled schedule
                            if ( typeof row !== "undefined" ) {
                                timeToByteBuffer( row[ 'time' ] ).copy( new_schedule );
                                new_schedule[ 2 ] = row[ 'target' ];
                            }
                            comfort = Buffer.concat( comfort, new_schedule );
                        }
                        items.push( dcb_entry( (days == 2 ? 47 : 103) + day * 12, comfort ) );
                    }
                }
                break;
            case 'timer':
                // Hot water control program
                if ( model.match( /^(PRTHW|TM1)$/ ) ) {
                    var days = data[ key ].length
                    var days_expected = status.config.progmode == '5/2' ? 2 : 7
                    if ( days != days_expected ) {
                        throw "Incorrect number of days specified for hot water control program " + days + ". Expected " + days_expected;
                    }
                    for ( var day = 0; day < days; day++ ) {
                        var timer;
                        for ( var entry = 0; entry < 4; entry++ ) {
                            var row = data[ key ][ day ][ entry ];
                            timer.concat( typeof row !== "undefined" ? timeToByteBuffer( row[ 'on' ] ).concat( timeToByteBuffer( row[ 'off' ] ) ) : [ 24, 0, 24, 0 ] );
                        }
                        items.push( dcb_entry( (days == 2 ? 71 : 187) + day * 16, timer ) );
                    }
                }
                break;
            default:
                // HERE - Need to add support for item 26 (TM1 countdown)
                // Other settings are not writable (including basic configuration)
                // Feature 01: $status->{config}->{units}
                // Feature 02: $status->{config}->{switchdiff}
                // Feature 05: $status->{config}->{outputdelay}
                // Feature 06 (06-10): Communications settings
                // Feature 07 (11): $status->{config}->{locklimit}
                // Feature 08 (12): $status->{config}->{sensor}
                // Feature 10 (14): $status->{config}->{optimumstart}
                // Feature 12 (16): $status->{config}->{progmode}
                throw "Unsupported item for writing: " + key;
        }
    }
    callback( items );
}

module.exports = Wifi;