tech@lifx.co responses #1

Now that we know where we stand in regards to funding (thank you to all our backers), we can settle into the engineering and delivery of LiFx.  Regardless of our KickStarter campaign still having another 52 days to run, we aren't waiting to roll-up our sleeves and will continue work unabated.

Receiving significantly more funding than we expected means that we can tackle the project differently and better than originally planned.  LED and microcontroller vendors have approached us last week and their proactive support will make a big difference.

On Friday evening (AEST), I had a conference call with the team behind a well-known commercial embedded controller / radio.  Their friendly willingness to share information and their extensive resources was very encouraging.  Whilst we had already chosen an embedded microcontroller / radio for our prototype, which was our default decision for production.  It is reasonable to reevaluate that decision in light of what experienced vendors are now willing to offer us.  One criteria will be that our preferred choice of software stack and communications protocols will run on whatever we choose (no, we aren't going to throw everything away and start again).

It is clear that communicating regularly and openly with our backers and the developer community at large is of the utmost importance.  We really appreciate it when LiFx supporters (like Ryan) take the time to answer the questions of others, when we have dropped the ball or succumbed to sleep.  However, the responsibility ultimately rests on our shoulders to provide information and to correct misinformation.  Building up a developer community that helps us, to in return, help the community is the only way we can scale.

Our email address for technical (not business) queries is tech@lifx.co and rather than reply to individual emails ... we'll be summarizing the questions and answers here, when they are of general interest.

And now for some of those answers ...

Networking (WiFi, LAN, WAN)

  • Do I need a 802.11n router or it works also over 802.11g ?

    The WiFi module chosen works with 802.11 b/g/n routers.

  • Since the initial configuration is done via an App. You have to configure the App with your router information and password and it passes that along to the master light bulb. Is it possible for someone to snoop this ?

    As with any network connected device, LiFx is potentially introducing another attack vector into your local network.  We will work through each scenario carefully to avoid compromising your WiFi security information.  Whenever we can use a standard wireless security mechanism, e.g WPA2, we will.  People have pointed out that ad-hoc networking won't work on all phones, which means we will have to provide alternative set-up / configuration mechanisms.  As we work through the details, this technical blog will be the place to track progress.
  • Can you describe how to access my LiFx smart-bulbs at home when I am on another network ?

    Since the LiFx master lightbulb appears on your local network (LAN) as a regular IP device, then the same techniques you would use to provide remote access to other services on your LAN will work for LiFx.  As we get closer to delivery, we'll provide tutorials to guide people through commonly requested scenarios.  Using secure tunnels or VPNs is strongly recommended.

  • Are you considering supporting LiFx connectivity over Cellular networks ?

    No.  Not for the KickStarter delivery.  However, the LiFx message protocol will be published and we'll happily help the developer community build useful deployment solutions for different network types.  This will be the same as supporting any other IP based connection over the cellular network.

Networking (mesh)

  • If my neighbor in a apartment building has LiFx, won't my smart-bulbs auto-connect to his master bulb and some of his auto-connect to my master-bulb ?

    That sort of comedy would be great for April 1st, but quite frustrating at other times !

    You tell your LiFx master lightbulb to expect a new slave lightbulb (soon) and select a color and number of "blinks".  When your slave lightbulb discovers a master looking for new slave, then the slave will then blink with the chosen color.  If the color and blink count aren't correct, the slave lightbulb will cycle to the next choice of available master.

    You don't want some random person's LiFx lightbulbs joining your network.  In that case, your master lightbulb under normal operating conditions will not be responding to new slave lightbulb join requests.
  • If you order the 4 light set from KickStarter, are they all "master" light bulbs and those that aren't going to be the master end up being slaves ?

    No.  The set of 4 consists of one master and three slaves.  However, there has been some confusion about this matter ... and even concerning our choice of calling them "master" and "slave".  Our business people are aware of this.  No promises are going to be made here on the technical blog, but I know that the LiFx team will work to avoid disappointing our backers.
  • Are the circuits different in slave lights ?

    The difference between the master and slave lightbulbs is the WiFi module.  If we can leverage the similarities between lightbulbs to provide cheap and cheerful solutions to the concerns about single-point-of-failure regarding the master lightbulb or people wanting to deploy in multiple locations, then that will be our preference.

Application

  • Will multiple devices be able to control the lights at the same time ? So from my iPhone, my iPad, my wife's iPhone, etc. ?

    Yes.  We have been using messaging over TCP/IP.  However, should the number of simultaneous connections to the small embedded microcontroller be exceeded, then we can consider falling back to UDP.
  • Will there be any ability to pair bulbs with certain devices ? I live in a shared house and if I bought these for everyone I would want bedroom lights to only be controllable from the owners phone.  Although trust is important, I wouldn't want a housemate accidentally turning on your lightbulb or changing your settings.

    Selective access control is not part of our planned delivery.  However, it is a good idea.

    Providing properly secure access control will be a non-trivial development effort, including security key exchange between the phones and the LiFx lightbulbs, along with robust authentication and administration of the lightbulb network.

    However, if you are relying on personal trust and just wish to avoid accidental mistakes in an environment where people respect each others boundaries, then providing a light-weight access mechanism that only presents the controls for specified lightbulbs on a given phone is something that could be considered.  And, when the LiFx API is published, then you can always create your own user interface clients.
     
  • Given that the LIFX supports colors, effects and synchronization with audio media, it seems entirely possible to do the same with video.

    That's a very cool idea, but not something we're aiming to provide as part of the KickStarter delivery.

    We just can't wait to see what our supporters do with LiFx.  Some of the messages we've received have been suggestions about ways in which network controllable lights can improve the quality of life for disabled people.  If you are working on any technology projects, this is an important goal to always keep in mind.

Automation

  • Automatic on and off: how does this work ? How will the bulbs know when I come home or leave ?  WiFi proximity ?  Bluetooth 4.0 ?

    GPS.  If we have time, then network based proximity would be good to implement.
  • It would be super cool if your device could also simulate the X10 signals across the house wiring to allow your device to control X10 modules as well.

    Yes, it would.  But, not as part of the KickStarter delivery.  If we can help the development community build out these additional good ideas, then that would be a great outcome.  There are simply too many different automation protocols for us to contemplate tackling right now.

    Having said that, there are several X10 modules sitting right next to me :)

LED related

There have been many comments and questions about the LED specifications.  Currently, we are in discussion with LED manufacturers.  When an LED for the production of LiFx smart-bulbs has been selected, we will let you know the detailed specifications.  Rest assured, we want the best choice possible ... everyone dislikes poor lighting.  Until then, only questions of a general nature can be answered.

  • Wonder about the need for all bulbs to be RGB rather than simply warm or neutral white ?

    That's a good idea, but not for the KickStarter delivery.  We based our KickStarter campaign on RGB LEDs and need to focus on delivering that properly first.
  • My wife has an issue with bulbs. In her mind, they need to be 'full-spectrum.'

    Everyone is making great suggestions, but we have to say ... sorry no, it'll be RGB LEDs only.  After KickStarter, then it'll be a different matter ... and we may tackle "full spectrum white" LEDs, if there is sufficient interest.
  • What is the CRI rating of the light across different color temperatures ?  Specifically at tungsten 3200K and daylight 5600K ?  Any plans for daylight and tungsten presets or ways to lock in at those temps with out inducing any green / magenta ?

    The CRI (Color Rendering Index) is lower for LED lights compared to incandescent light sources.  There appears to be doubt about whether the current industry standard for measuring CRI is even appropriate for LED lights.  However, LED lights with lower CRI ratings than incandescent lights can still reproduce colors acceptably well.

    The LiFx App will have preset color values that can be customized.  We've noticed some discussion amongst photographers about the advantages of having networked controlled RGB LED lights.   Photographers that care a lot about color reproduction may have expectations higher than what we are initially aiming for with the KickStarter LiFx delivery.

    I found this blog post by Cool Lights (not affiliated with LiFx) to be quite illuminating on the concepts behind light sources and color reproduction.  We will provide full LED light specifications, as soon as we can.
  • How many foot-candles a bulb can make when put in the "white" mode and more or less when put in a blueish or reddish color. If you don't have this information, do you have any data for light power compared with a 100w tungsten bulb ?
  • What brightness are the bulbs in white light ... in comparison to Australian Standards ?
  • As such the website says the bulb is equivalent to a 60 Watt bulb. My question is what is the LUX output at its max settings on white ?

    We'll hold onto all these and similar questions and answer them as soon as we can.  Clearly, some people care deeply about these details ... and it is important that we give correct answers based on measurements we make and not rely purely on the published specifications.

    Typically, we'll make comparisons against a 60 Watt lightbulbs, but will try and accommodate a greater range of testing, if we have time.

Light fixture

  • Is the downlight version MR16 or GU10 or both ?

    GU10 (mains powered) only.
  • Can you confirm (and perhaps spell it out in the FAQ) - the downlight flavour will be GU10 (mains powered) and not MR16 (12V external transformer powered) ?
    This is important as it means I have to consider getting a sparky in to convert my 12V halogens to GU10 fittings. And possibly replace the downlight gimbals.

    Initially, we did not intend to offer downlights at all.  However, we have decided to include GU10 mains powered downlights, because that can be done with only a change to the housing, whilst retaining the same power supply and electronics.

    We will not be offering MR16 as part of the KickStarter delivery, because that would also require a power supply design change.  We were so very tempted to go that extra step, but unfortunately must decline.

Non-technical

  • Do I have to add manually $20 when I checkout or I'll pay the international shipping in a next step ?

    If you are in the U.S, Canada or Australia, then shipping costs are included.  Otherwise, you should add the international shipping cost stated in the pledge level sidebar, when you make the pledge.  KickStarter has an FAQ that discusses changing your pledge amount, should you decide that it is necessary.
  • What sort of warranty will you be offering ?

    Copied from the bottom of our KickStarter page ...

    "We are still working out the exact details of the warranty for the LIFX smart bulbs.  To ensure that we comply with the legal requirements across a number of different countries, we decided its best that we seek legal advice to ensure that we are compliant."

Regards ... Andy (@geekscape)

Q: Why hasn't the LiFx engineering team been more responsive ?

A: Because you have overwhelmed us !

Sorry that you haven't heard from me sooner.  It takes a couple of days to adjust, when struck by internet lightning.

We realize how important it is to respond honestly, accurately and promptly to the comments and questions raised by our genuine backers.  This technical blog is one of the key places where we will do that.  Since it is a technical blog, it will be mostly about the engineering and not as much about the non-technical matters that arise as part running a KickStarter campaign.

We are working over a time-frame of 2 months for the KickStarter campaign and then around 4 months for the production development and delivery of the LiFx smart-bulbs.  Our plans and decisions of last week anticipating a modest result ... now need to be scaled up to handle a project that is potentially an order of magnitude larger.  For those reasons, our technical dialogue will be on-going and not all questions can be answered immediately and in complete detail (even though we all want that).  It will happen as the engineering effort progresses.

Not only have we been reviewing all the KickStarter comments ... we've also been paying attention to the discussions occurring out there in the blogosphere.  Many of the comments are insightful and valuable, including ones that have raised valid technical concerns ... those are greatly appreciated.

Some of the seemingly simple questions, e.g "Please tell us the LED CRI rating ?" can be tricky to answer (IMHO) when further research indicates that whilst CRI (Color Rendering Index) is a meaningful number for incandescent and CFT light sources, it isn't as meaningful for LEDs.  What we would have done, before our backers went ballistic, was source the best possible LEDs we could and report on the specifications when we knew them.  Now, we are are hearing from very experienced LED people who can help us make a better choice on your behalf.  So, it will be best to hold off on providing premature and ultimately inaccurate information.  Of course, we will keep you updated via this technical blog as we make progress.

An approach I'd really like to follow is "Please don't feed the internet trolls".  We must focus our complete attention on delivering your pledges and answering your questions and comments.  LiFx has attracted a lot of attention, not all of it good.  Some people are just waiting for a large KickStarter project to fail, without any regard for the interests of the supporters of that project.

We've all seen the Reuter's opinion piece and I don't want to waste time responding to it.  Primarily, because I don't need to respond ... thanks to "KenG_CA" whose comment at the bottom of that opinion piece has already made a rebuttal.  Thanks Ken ... whoever you are !  I have nothing more to say about that piece.

I realize this post has not answered any technical questions ... and providing those answers is at the top of my to-do list.  Your fantastic support has literally changed our lives, it's a big adjustment ... and I sincerely thank you for the great opportunity that you've provided us to make something great.  Let's go !

Regards ... Andy

How do I connect LiFx to my WiFi network ?

Given that light-bulbs (even smart ones) don't have a standard user interface, then it is reasonable to ask how can details like your WiFi network SSID and password be conveyed to the LiFx smart-bulb that is acting as the WiFi bridge.  When the LiFx master smart-bulb is first turned on ... it configures its WiFi module in ad-hoc mode with a known SSID and you connect your mobile device to that network, as follows ...

  • Download the LiFx App onto your mobile device
  • Install and turn on the LiFx master smart-bulb (contains the WiFi bridge)
  • Change your mobile device WiFi settings to connect to the ad-hoc wireless network called “LiFx”
  • Start the LiFx App on your mobile device and wait for it to connect to the master smart-bulb
  • Enter your WiFi network SSID and password and press the [Configure] button
  • The master smart-bulb will then connect to your WiFi network
  • Close the LiFx App on your mobile device
  • Change your mobile device WiFi settings to connect to your WiFi network
  • Restart the LiFx app on your mobile device
  • Install and turn on any slave smart-bulbs
  • The slave smart-bulbs will discover the master smart-bulb
  • Your LiFx smart-bulbs are now ready for action !
Having answered that question ... has immediately raised several more questions !
  • How is the ad-hoc network connection secured, so that my WiFi password isn't exposed ?
  • What are the details of the slave smart-bulbs discovering the master smart-bulb ?
  • If my neighbor also has LiFx ... what stops my slave smart-bulb connected to their network ?
  • What if I want to move some smart-bulbs to another location ... how do I reconfigure ?
To keep the answer to the original question clear and concise, we will attempt to answer all these questions in an on-going manner and not all at once in a monster blog post :)

Thanks for all your questions and feedback ... you are certainly keeping us on our toes !

Is the LiFx Wifi network connection and mesh networking secure ?

Yes, we have considered security.  The WiFi connection will use the standard security set-up that you are currently using.  Mesh networks based on 802.15.4 will encrypt packets using AES-128.  Higher network stack layers will need to handle exchange of security keys and deal with problems like “replay attacks”.

Can I write my own lighting sequences ?

Yes, each smart-bulb runs a tiny scripting engine.  You will be able to upload sequences that control the colours over time.

How many LiFx smart-bulbs can be in a single network ?

Our prototype system was tested with a master and 9 slave smart-bulbs.  Our choice of networking hardware and software stack will allow hundreds of smart-bulbs.

How do I connect LiFx to my home automation system which is brand X?

Since we will provide LiFx client libraries and document the LiFx protocol API, if your home automation system is extensible (nearly all are) and you know how to interact with it programmatically … then, you can create “glue” software that integrates them.

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