homebridge-sensor-autostart-switch/index.js

Install this plugin

var Service, Characteristic;

var state = true;

var Gpio = require('onoff').Gpio;
var clos = 0;

module.exports = function (homebridge) {
    Service = homebridge.hap.Service;
    Characteristic = homebridge.hap.Characteristic;

    homebridge.registerAccessory("homebridge-sensor-autostart-switch", "sensautoswitch", sensautoswitchAccessory);
};

function sensautoswitchAccessory(log, config) {
    //config
    this.name = config["name"];
    this.pin = config['pin'];
    this.timeopen = config["timeopen"];

    //setup
    this.log = log;
    this.service = new Service.ContactSensor(this.name);
    this.service
        .getCharacteristic(Characteristic.ContactSensorState)
        .on('get', this.getState.bind(this));

    var relay = new Gpio(this.pin, 'out');
    relay.writeSync(0);
    
    clos = 1;
    this.service.setCharacteristic(Characteristic.ContactSensorState, clos);   
    setTimeout(function(){ 
        relay.writeSync(1);
    }, 10000 * this.timeopen);
}

sensautoswitchAccessory.prototype.getState = function (callback) {
    callback(null, state);
};


sensautoswitchAccessory.prototype.getServices = function () {
    return [this.service];
};