pi-gpio does not turn on/off the pin

Question

I installed the HAP-NodeJS and I am using the Light_accessory.js to control a light. I Also installed pi-gpio and when the server is running I see that the state changes from 0-1 and vise versa. The lights does not turn on/off. Do you have any ideas?

The LED diagram is like that, I am using pin 12 as the GPIO pin:

Here is the code that turns the pin on/off:

var gpio = require("pi-gpio");

// HomeKit types required
var types = require("./types.js")
var exports = module.exports = {};

var execute = function(accessory,characteristic,value){ console.log("executed accessory: " + accessory + ", and characteristic: " + characteristic + ", with value: " +  value + "."); }

exports.accessory = {
  displayName: "Light 1",
  username: "1A:2B:3C:4D:5E:FF",
  pincode: "031-45-154",
  services: [{
    sType: types.ACCESSORY_INFORMATION_STYPE, 
    characteristics: [{
        cType: types.NAME_CTYPE, 
        onUpdate: null,
        perms: ["pr"],
        format: "string",
        initialValue: "Light 1",
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Bla",
        designedMaxLength: 255    
    },{
        cType: types.MANUFACTURER_CTYPE, 
        onUpdate: null,
        perms: ["pr"],
        format: "string",
        initialValue: "Oltica",
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Bla",
        designedMaxLength: 255    
    },{
        cType: types.MODEL_CTYPE,
        onUpdate: null,
        perms: ["pr"],
        format: "string",
        initialValue: "Rev-1",
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Bla",
        designedMaxLength: 255    
    },{
        cType: types.SERIAL_NUMBER_CTYPE, 
        onUpdate: null,
        perms: ["pr"],
        format: "string",
        initialValue: "A1S2NASF88EW",
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Bla",
        designedMaxLength: 255    
    },{
        cType: types.IDENTIFY_CTYPE, 
        onUpdate: null,
        perms: ["pw"],
        format: "bool",
        initialValue: false,
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Identify Accessory",
        designedMaxLength: 1    
    }]
  },{
    sType: types.LIGHTBULB_STYPE, 
    characteristics: [{
        cType: types.NAME_CTYPE,
        onUpdate: null,
        perms: ["pr"],
        format: "string",
        initialValue: "Light 1",
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Bla",
        designedMaxLength: 255   
    },{
        cType: types.POWER_STATE_CTYPE,
        onUpdate: function(value) {
            gpio.open(12, "output", function(err) {
                gpio.write(12, value, function() {
                    gpio.close(12);
                });
            });
        },
        perms: ["pw","pr","ev"],
        format: "bool",
        initialValue: false,
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Turn On the Light",
        designedMaxLength: 1    
    },{
        cType: types.HUE_CTYPE,
        onUpdate: function(value) { console.log("Change:",value); execute("Test Accessory 1", "Light - Hue", value); },
        perms: ["pw","pr","ev"],
        format: "int",
        initialValue: 0,
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Adjust Hue of Light",
        designedMinValue: 0,
        designedMaxValue: 360,
        designedMinStep: 1,
        unit: "arcdegrees"
    },{
        cType: types.BRIGHTNESS_CTYPE,
        onUpdate: function(value) { console.log("Change:",value); execute("Test Accessory 1", "Light - Brightness", value); },
        perms: ["pw","pr","ev"],
        format: "int",
        initialValue: 0,
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Adjust Brightness of Light",
        designedMinValue: 0,
        designedMaxValue: 100,
        designedMinStep: 1,
        unit: "%"
    },{
        cType: types.SATURATION_CTYPE,
        onUpdate: function(value) { console.log("Change:",value); execute("Test Accessory 1", "Light - Saturation", value); },
        perms: ["pw","pr","ev"],
        format: "int",
        initialValue: 0,
        supportEvents: false,
        supportBonjour: false,
        manfDescription: "Adjust Saturation of Light",
        designedMinValue: 0,
        designedMaxValue: 100,
        designedMinStep: 1,
        unit: "%"
    }]
  }]
}