Candle - the privacy friendly smart home

  • Plugin Developer

    At the upcoming Dutch Design Week from 19 till the 26th of October me and my team will be launching a project called "Candle". It's a privacy friendly smart home demonstrator that is built on, amongst other things, MySensors.

    Candle's goal is to accelerate the development of more privacy friendly smart devices by showing examples of what this future could look like. It proves you don't have to choose between privacy and easy of use. With good privacy design you can have both.

    We have asked artists and designers to create prototypes based on the code and electronics I developed. For example, juweler Dinie Besems created devices with a luxury appeal.

    CO2 sensor by Dinie Besems
    CO2 sensor

    Fine dust sensor by Dinie Besems
    Fine dust sensor

    More on her creations here.

    Engineer Paola Rodrigues also created two devices. This is her version of the Signal hub:

    Signal hub by Paola Rodrigues
    The signal hub can copy and/or learn to recognise 433Mhz devices

    And her version of the temperature, humidity and barometer device (using the BME280):
    Weather station by Paola Rodrigues
    Paola added extra LED's to make the sensor levels readable from far away.

    At the moment designer Jesse Howard, an expert on Open Design, is finishing work on his creations.


    Using MySensors allowed us to really push a number of narratives that are juxtaposed to current IoT design practices:

    • Smart devices often use wifi to connect to the home network and the internet. To us, both of these things were unacceptable. If devices can access the internet themseles, who knows what they are sending. If they can connect to the home network, they form an attractive entrypoint for hackers looking to access other devices on the home network. MySensors, Zigbee/Z-wave and even Bluetooth were more acceptable to us, since since they form their own local network which can be kept separate.
    • Smart devices are often overpowered. Big arm chips, together with the wifi connection, make them an attractive target for hackers, who can use them as beach heads for further invasion of the home network. Candle uses 'minimal viable hardware', in this case the RF Nano. This decreases the attack surface.
    • The power of open source allows users to inspect the code, and thus gain/rebuild trust. In some cases the hardware reflects this call for transparency by being literally transparent. No hidden microphones here.
    • The power of open source allows users to learn more about their technology, and even modify it. It's empowering.


    A secondary goal was to allow users to relatively easily create the devices themselves. Besides creating the MySensors add-on for the Mozilla WebThings Gatway we also created the Candle Manager add-on. This makes it easy to upload MySensors code to an Arduino. Just connect it through USB to the central controller, and follow the steps in an easy to use interface. Arduino code is then compiled and uploaded to the board, thanks to the new Arduino CLI.

    Candle Manager
    The Candle manager

    To aid in education, all Candle devices can be made without needing to solder. Dupont wires are all you need.


    MySensors allowed us to quickly prototype and test new privacy enhancing designs and ideas. Some examples are:

    • All Jesse's devices can be disconnected from the MySensors network with a physical hardware switch. While the devices gain functionality when networked together, all of them will also work fine as stand alone devices. For example, all sensors have their own screens to display their current values. Ideally, all smart devices should have a switch with three settings: (1) do not talk (2) data may be shared within the local (MySensors) network (3) Data may shared locally and with the internet.
    • The CO2 sensor has the option to generate 'fake data' by toggling a hardware switch. If you turn this on, it will generate more data that is similar to the last few real measurements. Why it is important to have this feature is explained in depth on the website.

    Most of the source code can already be found on Github, including the MySensors sketches. More of the code being will be uploaded as the launch exhibit draws closer.


    This project has been made possible with support from the Creative Industries Fund NL. The creation of the machine learning aspects of the project were supported by the SHERPA project, which is a Horizon 2020 research project by the European Union.

    I want to give a special thanks to @Anticimex for creating the user friendly security options. Thank you!


    I am still looking for volunteers that would like to create one or more of the Candle devices and have their creation exhibited alongside the other works. We will pay for your hardware and materials costs. If you're interested, send me a message.

    If you're in the Netherlands at the end of October, please come and say hi at the exhibit.

  • Contest Winner

    @alowhum thanks for the shout out 🙂 it is inspiring to see how the envelope really can be pushed with open source powered hardware and software. Really impressive stuff!

  • Hardware Contributor

    @alowhum said in Candle - the privacy friendly smart home:

    I am still looking for volunteers that would like to create one or more of the Candle devices and have their creation exhibited alongside the other works. We will pay for your hardware and materials costs. If you're interested, send me a message.

    Too bad there's only a bit over a month left, it's too short to design something.
    The concept is really great, I love the idea of the physical switch for stealth mode.

  • Plugin Developer

    @nca78 You'd only have to create a housing really. The bar is pretty low: in workshops people just screw the electronics to the back of a wooden plate 🙂

  • Plugin Developer

    Here's a sneak preview of the custom PCB that was created for the CO2 sensor:

  • Plugin Developer

    And here are some initial photos of Jesse's creations:

    Smart lock

  • Plugin Developer

    Today the project was featured on Hackaday 🙂

  • Hi Guys,

    I have the RPi 4b 4gb and the oriinal Raspberry 7" touchscreen / display.

    I'm trying out Candle Smart Home for the first time and relatively new to RPi's, but have some knowledge with Arduinos.

    In the instructins with connecting the touchscreen, it states connect the HDMI on the display to the HDMI on the RPi, then connect the USB of the display to the usb on the RPi.

    Which USB on the RPi am to use?


  • Contest Winner

    @Dizzwold Not sure if I understand your question correctly. As PI's have multiple USB ports it doesn't matter which one you use. So I'd say use any of the available USB ports. But some how I have the feeling you have a different question

  • @TheoL, Thanks for the reply.

    No Iwasn't asking for something else.

    I didn't realise I could use any of the USB ports, I thought I had to use one particular port.

    Now I maybe jumping the gun a little here;

    I've reinstalled webthings gateway, candle, candle manager, mysensors, voco, seashell (typed in the command line). I don't have any sensors or things as yet and I've not uploaded a floorplan. I have a small TV connected by HDMI and the Raspberry officail 7" touchscreen (800 x 400).

    I get the candle splash screen, but then nothing but a blank screen, also on the 7" touchscreen the candle splash is upside-down.

    Do I not see anything as I've not uploaded a floorplanand/or have no sensors or things?

    How do I rotate the touchscreen?


  • Contest Winner

    @Dizzwold Oh you're asking a lot of questions that are all about the candlelight project and not so much on mysensors lol. I know you can configure the raspberry to change the rotation of the screen. But it's something you have to google. As of the candle. I've never installed it. But I suggest you have a look at the log files?

  • Hi Guy's,

    My appologies if I've come to the wrong place or posted in the wrong area, but this is the only place I've found that comes remotely close to a Candle Smart Home Forum.

    I've googled for Candle Smart Home Forums and the candle website has very little in the way of a "Contact us" link or form.

    If anyone knows where I should be asking, I'd be more than grateful for the information.

    Sorry for being Off Subject, I didn't intend to hijack the thread, I just haven't found anywhere else to ask.

  • Since Candlelight is based on MySensors, it could spark some new comers to this space if Candlelight had it's own topic. I mean, most of the controllers have their own topic. Why not.

  • Hardware Contributor

    @alowhum are you still around ?

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