Touch & Speak: Bare Conductive's TouchBoard with Bacon.js

app.js

// Touch Board Example
// ===================
// Connects to a touch board and 'says' a word when a touch is detecte

// Modules
// ======= 
var serialPort = require( 'serialport' );
var Bacon = require( 'baconjs' );
var W = require( 'w-js' );
var say = require( 'say' );

// Touchboard Module 
// =================
//  
// Example usage:
// 
//   touchBoard()
//       .error( doThrowError )
//       .success( onReady );
//  
//   function onReady ( touchBoard ) {
//     
//   }

function TouchBoard ( comPort ) {
    return W.promise( function ( resolve, reject ) {

        // Open the device
        var serial = new serialPort.SerialPort( comPort, {
            parser: serialPort.parsers.readline( '\r\n' )
        });
        
        serial.open( function ( err ) {

            if ( err ) { return reject( err ); }
            
            // Set it up
            var dataStream = Bacon.fromEvent( serial, 'data' )
                    .map( buffer => buffer.toString() )
                    .map( d => d.split( ' ' ) )
                    .filter( arr => arr.length > 0 )
                    .filter( arr => arr[ 0 ].indexOf( ':' ) > -1 );

            function filterByType ( stream, eventType ) {
                return stream
                    .filter( arr => arr[ 0 ] === eventType + ':' )
                    .map( W.rest )
                    .skipDuplicates( function ( oldArr, newArr ) {
                        return !oldArr.reduce( ( acc, v, idx ) => { if ( v !== newArr[ idx ] ) { acc = true; } return acc;  }, false );
                    });
            }

            // Retuen the different data streams
            resolve( {
                dataStream: dataStream,
                touchStream: filterByType( dataStream, 'TOUCH' ),
                thresholdStream: filterByType( dataStream, 'TTHS' ),
                releaseStream: filterByType( dataStream,'RTHS' ),
                filteredStream: filterByType( dataStream, 'FDAT' ),
                baselineStream: filterByType( dataStream, 'BVAL' ),
                differenceStream: filterByType( dataStream, 'DIFF' )
            });
            
        });
    });
}

// Speaking
// ========

// The speachBus is a bacon stream which we can push *values* on to. I.e. we can push things we want to say on to this stream
var speachBus = new Bacon.Bus();

// Make the speachBus consumer that when recieveing data it will *say* the data
speachBus
    .throttle( 100 )
    .onValue( text => say.speak( 'Alex', text ) );

// Implement the TouchBoard
// ========================

TouchBoard( '/dev/cu.usbmodem1411' )
    .error( doThrowError )
    .success( function ( touchBoard ) {

        sayOnPin( 0, 'happy' );
        sayOnPin( 1, 'birthday' );
        sayOnPin( 2, 'to' );
        sayOnPin( 3, 'you' );
        sayOnPin( 4, 'Jemma' );

        function sayOnPin( pin, text ) {
            touchBoard.touchStream
                .map( arr => arr[ pin ] )
                .skipDuplicates()
                .filter( v => v == 1 )
                .onValue( function () {
                    console.log( '------------------' );
                    console.log( text );
                    speachBus.push( text );
                });
        }
    });

// Utils
// =====

function doThrowError( err ) { throw err; }