Candle - signal Hub - A universal 433Mhz signal detector and cloner

  • Plugin Developer

    It took three weeks to build, but here it is: a device that will easily connect almost any 433Mhz device to your smart home.

    The 433 Hub can do two things:

    • You can teach it a signal, and from then on it will be able to detect it.
    • You can teach it a signal, and from then on it will be able to replay it.

    Both of these features come in 'single signal' and 'on+off" versions. So for example:

    • You could copy the ON and OFF button from a remote for your 433Mhz sockets, and from then on switch the socket from your smart home controller.
    • You could teach it to detect window sensors that have both on and off states.
    • You could teach it to detect the alarm signal from a wireless smoke detector.

    For each signal that you teach it to recognise, a door sensor will be presented to your controller.
    For each signal that you teach it to replay, an on/off switch will be presented to your controller.

    Signals take between 8 and 28 bytes to store, depending on complexity and if they are simple or on+off signals. This means an Arduino Nano can store between 20 and 60 signals in just half of it's eeprom (512 bytes).


    • Arduino

    • 433Mhz receiver & transmitter

    • Touch screen (optional, recommended)

    • OLED screen (optional)

    • Keypad (optional)

    Here's the version that uses a touch screen.

    Here's a version that uses a keypad.
    With a 12 button keypad you can easily replay 10 signals. The last two buttons are used to navigate and make selections in the menu system.

    You can also trigger the learning sequences from 4 virtual buttons that the device creates on your controller (detect simple, detect on+off, replay simple, replay on+off).

    It works best if you use the touch screen. Using the menu you can delete the last recorded signal, or delete all recorded signals.

    It's designed to work with the upcoming Candle privacy friendly smart home, and the Candle Manager. More on that later this year.


  • @alowhum So this can act as a kind of learning remote, correct?

    Nice work by the way.

  • Plugin Developer


    And a learning detector at the same time.

  • Plugin Developer

    The touch screen code is now also available.

  • Plugin Developer

    Something I had hoped actually works: it can also copy IR (infrared) signals!

    Settings need to be slightly different, as IR signals are 'slower' than RF signals. Changes I made to the settings are:

    #define MAXEDGES 100            // instead of 400                    
    #define GRANULARITY 100       // the default settings of '50' also work, but IR signals need less precision.
    #define MAXIMUMDURATION 66000
    #define MINIMUMSILENCE 66000

    It doesn't recognise things perfectly, as IR signals don't seem to repeat themselves in the same way. You may have to press the button a few times before the signal can be copied.

    I also haven't tested if transmitting the signals actually switches IR devices on and off.

    An example:

    00000000 > 0
    11110111 > 239
    00010000 > 8
    11101111 > 247

  • Plugin Developer

    • It can now handle even more 433 signals.
    • Slight code simplification

  • Probably a bit of a noob question, but if I don't have any of the optional items, can I still use this? Will it just save the RF commands until it can't save anymore?

  • Plugin Developer

    @Homer yes

  • @alowhum said in Candle - signal Hub - A universal 433Mhz signal detector and cloner:

    @Homer yes

    Thanks, and thanks for your private messages!

    I managed to build a rf433 sender which is connected to wifi and is outside of the Mysensors environment, and it works, but I can't get my controller (Vera) to communicate with it. This looks like it should work perfectly for what I want it to do!

    Thanks for sharing!

  • I am having issues with the device I made myself which doesn't use this code, so I have decided to give this project a go. One problem though... I copied the sketch from you link, and even without any changes or alterations, the sketch doesn't compile. It gets to line 468 and says "detectedMessage" was not declared in this scope.

  • Please ignore the above.... I don't know why but I just tried it again and it compiled immediately.

  • I just worked out what I did! I had commented that I didn't have a touchsceen and that caused the error. I thought I should do this as I don't have one, but I guess I'll have a go at uploading the sketch as it is.

  • Plugin Developer

    Thanks for the feedback. Let me know if you have any issues and I can try to fix them.

  • @alowhum I've finished building this. I have also bought a couple cheap window/door sensors to try, but I've hit a snag.

    When I joined this to my controller (Vera) it said that it found 2 devices, but when I check my devices I only find one device, and all it says is that it's a node; I have very little in the way of interacting with it. I'm not sure what's going on.... It's weird that it found two devices and only displays one! Seeing that I'm not using any screen, I can't do anything because I thought I could interact with the hub from within my controller. Have I done something wrong?

  • Plugin Developer

    I haven't tested it without a screen myself. I'll look into it for you and see if I can make the code work optimally without it. I'll get back to you with the updated code.

  • Awesome, thanks!!!

  • Plugin Developer

    Here is the new version which should work just fine without a touchscreen attached.

    I also added a new playlist feature. If multiple replay requests are received in quick succession (perhaps from a home automation rule that wants to trigger multiple sockets), it can remember these requests and replay them one after the other.

  • Awesome, thanks for your work! I'll be giving this a go today.

    The extra feature of it remembering if multiple commands are given is great too!

  • I've finally finished building this, but sadly it doesn't want to work with my controller (Vera). When I start the inclusion process I'm says that it has found 2 devices, but when the controller finishes setting it up it only ends up showing one device, and all it says is that it is a node.


    Has anyone built this and have had success with Vera? If you are using this, which controller do you use?

  • Plugin Developer

    It should not show a temperature sensor, since it doesn't have one. Are you sure it has actually connected? Try listening to the serial output of the node (using the Arduino IDE's option to do this), and check if it says that it has connected ok, and that is is showing you the decoded signals then you play the RF signal. You can even try enabling the debug option to get even more details about the node's state.

  • Thanks for the reply!

    It doesn't show a temp sensor. I circled the device that it shows, but of course I only circled one because the second device doesn't show.

  • @homer Look at your device list on a computer web browser. It appears that you are viewing it with the Vera app on your phone or tablet. I have seen where some devices don't show correctly on the Vera app. I don't know what type of device it will identify as, but you should see "<some device type> (12)" with the key being the (12) as that identifies the node that presented it. Also, do you have any 433Mhz devices that it may be detecting? Looking at the code a bit, it looks like it will present any 433Mhz devices that it sees to your Vera controller.

  • @dbemowsk thanks for your reply. Yes the screenshot was taken Vera using my phone, but I only did that as I was using the phone at the time. I went out to have a smoke lol after I tried on my laptop.

    From what I understand, it should have created devices that then allow for the inclusion of rf433 devices, but if that isn't the case, I'm happy to be corrected!

  • Plugin Developer

    @homer It creates one device. This device will get more children when it learns more codes.

    For example:

    • If you teach it a on+off code, the new child will be a toggle switch.
    • If you teach it to recognize a signal, the new child will be a motion sensor.

    If you are not using the touch screen, then you will also have 4 children that allow you to toggle the recording of the new signals.

    • A button to record a single signal that you want to be able to replay.
    • A button to start learning of an of+off combo signal (like a power socket that you can turn of and off).
    • A button to start learning a single detection signal (like a basic 433 window sensor)
    • A button to start learning a on+off detection signal (like a fancy 433 window sensor that supports both open and closed states).

  • @alowhum for some reason I'm never seeing those 4 children.

  • Plugin Developer

    @homer have you commented out the #define has_screen in the code? They only show up if you don't use a touch screen.

    Also, make sure you use the very latest code.