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var i2c = require('i2c-bus');

var BH1750 = function (opts) {
    this.options = opts || {
        address: 0x23,
        bus: 1,
        device: '/dev/i2c-1',
        command: 0x10,
        length: 2
    };
    this.verbose = this.options.verbose || false;
    if (i2c.openSync) {
        this.wire = i2c.openSync(this.options);
     } else {
        this.wire = new i2c(this.options.address, {device: this.options.device});
     }
    if (!this.wire.readBytes) {
        this.wire.readBytes = function(offset, len, callback) {
            this.writeSync([offset]);
            this.read(len, function(err, res) {
                callback(err, res);
            });
        }
    }
};

BH1750.prototype.readLight = function (cb) {
    var self = this;
    if (!cb) {
        throw new Error("Invalid param");
    }
    self.wire.readBytes(self.options.command, self.options.length, function (err, res) {

        if (err) {
            if (self.verbose)          
            return cb(err, null);
        }
        var hi = res[0];
        var lo = res[1];
        if (Buffer.isBuffer(res)) {
           hi = res.readUInt8(0);
           lo = res.readUInt8(1);
        }

        var lux = ((hi << 8) + lo)/1.2;
        if (self.options.command === 0x11) {
            lux = lux/2;
        }
        cb(null, lux);
    });
};

module.exports = BH1750;

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var Service, Characteristic;
var BH1750 = require('./bh1750.js');

module.exports = function (homebridge) {
    Service = homebridge.hap.Service;
    Characteristic = homebridge.hap.Characteristic;
    homebridge.registerAccessory('homebridge-rasspberypi-BH1750', 'illuminance', illuminance);
};

function illuminance(log, config) {
    this.log = log;
    this.log("Adding Accessory");
    this.name = config.name;
    this.sensor = new BH1750();
    this.refresh = config.refresh || "60"; // Every minute
}
illuminance.prototype = {
    identity: function (callback) {
        this.log("Identify requested!");
        callback(); // success
    },
    getServices: function () {
        this.log("INIT: %s", this.name);
        this.services.informationService = new Service.AccessoryInformation();
        this.services.informationService
            .setCharacteristic(Characteristic.Manufacturer, 'ZYD')
            .setCharacteristic(Characteristic.Model, 'Illumiance Sensor')
            .setCharacteristic(Characteristic.SerialNumber, this.name);
        this.log('creating Illumiance Sensor');
        this.services.illumianceService = new Service.IllumianceSensor(this.name);
        this.services.illumianceService
            .getCharacteristic(Characteristic.CurrentIllumiance)
            .on('get', this.getIllumiance.bind(this));
        setInterval(function () {
            this.getIllumiance(function (err, illuminance) {
                if (err) {
                    illuminance = err;
                }
                this.illumianceService
                    .getCharacteristic(Characteristic.CurrentIllumiance).updateValue(illuminance);
            }.bind(this));
        }.bind(this), this.refresh * 1000);

        return [this.informationService, this.illumianceService];
    },
    getIllumiance: function (callback) {
        this.sensor.readLight(function (error, value) {
            if (err) {
                this.log("light error: " + err);
                callback(err);
            } else {
                this.log("light value is: ", value, "lx");
                callback(null, value);
            }
        }.bind(this));
    }
};