index.js

'use strict';


var express = require('express'),
    cors = require('cors')
    pcsc = require('pcsclite');


var app = express(),
    pcsc = pcsc(),
    lastRead = false;


// Enabling CORS for all routes.
app.use(cors());


// API
app.get('/', function (req, res) {
    res.send(lastRead);

    // Preventing multiple reads of the same read.
    lastRead = false;
});


// Start web server.
var server = app.listen(3000, function () {
    var host = server.address().address;
    var port = server.address().port;

  console.log('Remote RFID server API available at http://%s:%s', host, port);
});


// PC/SC interface.
pcsc.on('reader', function(reader) {
    console.log('Reader detected:', reader);

    reader.on('error', function(err) {
        console.log('Error(', reader.name, '):', err.message);
    });

    reader.on('status', function(status) {
        console.log('Status(', reader.name, '):', status);

        // Check changes.
        var changes = this.state ^ status.state;
        if (changes) {
            
            // Card removed.
            if ((changes & this.SCARD_STATE_EMPTY) && (status.state & this.SCARD_STATE_EMPTY)) {
                console.log('Status(', reader.name, '): Card removed');
                
                reader.disconnect(reader.SCARD_LEAVE_CARD, function(err) {
                    if (err) {
                        console.log('Error(', reader.name, '):', err);
                    }
                    else {
                        console.log('Status(', reader.name, '): Disconnected');
                    }
                });

            }

            // Card inserted.
            else if ((changes & this.SCARD_STATE_PRESENT) && (status.state & this.SCARD_STATE_PRESENT)) {
                console.log('Status(', reader.name, '): Card inserted');
                
                reader.connect({ share_mode : this.SCARD_SHARE_SHARED }, function(err, protocol) {
                    if (err) {
                        console.log('Error(', reader.name, '):', err);
                    }
                    else {
                        console.log('Protocol(', reader.name, '):', protocol);

                        /* 
                            Read card UID: [0xFF, 0xCA, 0x00, 0x00, 0x00]

                            UID is specified in the ISO 14443 T=CL transport protocol while APDU's are specified in the ISO 7816 application layer protocol.
                            "Get Data Command" is defined in PCSC 3 v2. If your driver is PCSC v2 compliant, you can get UID using it:
                            Class = 0xFF
                            INS = 0xCA
                            P1 = 0x00
                            P2 = 0x00
                            Le = 0x00 (return full length: ISO14443A single 4 bytes, double 7 bytes, triple 10 bytes, for ISO14443B 4 bytes PUPI, for 15693 8 bytes UID)
                            
                            Expected response: Data+SW1SW2
                        */                        
                        var message = new Buffer([0xFF, 0xCA, 0x00, 0x00, 0x00]);

                        reader.transmit(message, 40, protocol, function(err, data) {
                            if (err) {
                                console.log('Error(', reader.name, '):', err);
                            }
                            else {
                                /*
                                    buf.readUIntLE(offset, byteLength[, noAssert])
                                    Set noAssert to true to skip validation of value and offset. Defaults to false.
                                */
                                lastRead = data.readUIntBE(0, 6, true).toString(16);
                                
                                console.log('Status(', reader.name, '): Read:', data, ' toString:', lastRead);
                            }
                        });
                    }
                });
            }
        }
    });

    reader.on('end', function() {
        console.log('Status(', reader.name, '): Removed');

        // Release resources.
        reader.close();
        pcsc.close();
    });
});

pcsc.on('error', function(err) {
    console.log('Error( PCSC ): ', err);
});