MySensors shield and RGBW Controller

  • Hardware Contributor


    I am currently working on getting some sensors set up at my place using mySensors. I really love the project, and how easy it is to build (most) sensors. Once I got the prototype running I need "professional" sensors though, which are easy to assemble, still cheap and can fit inside a small box of some kind.
    I am planning to use a cheap pcb manufacterer like, so the max size of the pcb is 5x5cm. This also goes well with the box part. I already got some battery holders, so all I need is the arduino + nrf + sensor on one board. Thats why I created my first design, a "motherboard"/shield which contains and arduino pro mini (3.3V) the NRF, a battery sensor and some small stuff. Also breakout pins for programming and an extra one for serial communication. The DHT11/22 can directly be placed on the pcb (because thats my most common sensor). Others sensors can be easily plucked into 2 connectors on the board as another shield. This makes it flexible but also easy to use with most kind of sensors. Power is an external part. I plan to use 3.3V wall power supplies or batteries, so no parts needed on the pcb. Didn't want to make it too complicated.
    The design is also only 25*50mm, so you can get two of them out of a cheap pcb.

    I am also planning to control lots of RGB(W) leds. Thats why I designed another pcb holding the same arduino pro mini + NRF combination, but also 4 mosfets for the different channels and a LM2596 buck converter module from ebay, which allows me to drive the whole thing directly from the 12 (or more)V power supply for the leds.

    I am thankfull for any comments or ideas how to optimize this and any errors you may find. I am planning to order them soon.

  • @LastSamurai Have you already designed these boards you mentioned or are you still in the planning phase? There are a few designs with similar specs elsewhere in the forum.

    Also, did you mean to post this in the Homeseer thread?

  • Hardware Contributor

    I think there might be a bug. THis is the second thread I posted in another topic, but which landed in the Homeseer thread. @Moderator please move this!

    I actually have already designed the ports. Here are the pictures.
    I found some other designs, but most of them tried to do too much for my taste. But if you can recommend some...!


    RGBW Controller

    Again, thanks for any feedback 🙂

  • Admin

    It will end up in the category you opened the coposer (even if you switch page). Where do you want to have it?

  • Hardware Contributor

    I thought thats what I did, but perhaps I misclicked 😉 I thought the hardware part would be right.

  • How many LEDs do you want drive with this controller, because the MOSFET has a limit of 4.6A.
    A full bright white LED (like a SMD5050) can have ~60mA current - so you can drive save 70 LEDs on a strip with this controller.

    But anyway, nice design 🙂

  • Hardware Contributor

    @hek Have you already moved it? I still see it in the homeseer section.

    @kalle Thanks for the hint. It should be enough in most cases for me, but better safe than sorry. Can you recommend a mosfet in SOT-23 package with a higher limit?

  • Sorry, I didn't find a sot-23 Mosfet with a higher limit, but maybe you have enough space to use TO-220. There are a lot of Mosefet's with a higher limit available - like this one.

  • Hardware Contributor

    Thanks for the feedback! I will try to add some bigger MOSFETs. Perhaps I can add both and make it optional. For now I finalised my shield. I moved the headers for the sensor, so that they are spaced like the arduino pro pins (distance). Also redid the routing and some other small parts. I just ordered them from dirtypcbs. Once I get them and they work I will add a link here if anybody else wants some.
    I guess next I will work on the rgbw shield again.

  • Hardware Contributor

    Yeah ✨ my PCBs from dirtypcbs finally arrived! So I instantly had to open the package and I must say: these pcbs are really well made (for that price). Here are pics. As you can see I designed them so that 2 fit on one 5x5cm pcb. So I have gotten myself 24 potential "smart" sensors now 😃
    I haven't gotten all components yet for multiple sensors but I started with one test sensor anyways. It has through hole resistors instead of some smd ones, no capacitor and no DHT22 yet. But once I get the components I will add them on the prototype. For now it's up and running with a demo sketch that just sends random values.
    And everything seems to be working nicely. Yeah^^

    Next step is to finalize the components and test some other components as arduino shield like components on the two pin headers I added for that one. And I already found some small things that I could still improve.

    Once that's all done I will finalize the RGBW ones and send them of for production.

    Love to hear your feedback and tipps guys!

    PS can I somehow add these pictures as thumbnails? They are quite big...
    IMAG0013.jpg IMAG0012.jpg IMAG0010.jpg IMAG0009.jpg IMAG0008.jpg

  • Hardware Contributor

    My test sensorboard has been successfully running for over a week now ✨
    It's only reporting fake values because my new sensors (DHT22) did not yet arrive but this looks good already.

    This night there was an "accident" though. Suddenly the sensor stoped sending data. When I took it from its "hiding"spot I saw that the second LED on the board was constantly on. Do you guys knwo what that is for?
    When I connected my serial to usb adapter to check the node's status the sensor powered up again and is since working perfectly again. The adapter does also power the board though. The battery levels are still reported as 3.4V so this should not be a problem. Any idea what the problem could be?
    I haven't added the capacitor yet... might that be the problem?

  • Hardware Contributor

    Ok, the same thing just happened again. Before the unit shut down it did restart about 3 times (thats whats in the log from my domoticz). Might this be the brownout shutdown? Voltage with external multimeter is at aboud 2.7-2.8V. So do I have to change my fuse settings? Or perhaps use the mysensor bootloader...
    I also realized that I did connect my batteries directly to the VCC pins, not the raw pin. This means that the voltage converter on the board isn't used (right?). Should I change that, or what's happening with the 3.3V converter if it gets input voltages lower than 3V?

    I also realise that my usb to serial converter might be running at 5V so I might have killed my NRF (and possibly the arduino too) 😞

    How do you guys handle this?

  • Is it available for other people yet? I am very interested in LED strip drivers connected to mySensor network and your PCB seems to fit the bill nicely.

    Good job.


  • Hardware Contributor

    Not yet, although the designs are above. I have to work out the errors in my normal pcb yet. Then I can easily switch over to the RGB(W) one.

    PS: Good part: both nrf and arduino are still working. Bad part: They shut down again after about a second. So it has to be a power issue. What are the right settings/fuses/things to keep the arduino pro mini (3.3V) running with batteries at 2.8V and lower?

  • Thanks for the response. I will be watching your progress closely as I am very interested in this.


  • Hardware Contributor

    It's a little sad that it took me so long but I finally managed to find a few minutes to "finalize" and test my sketch.
    Here is my working code for an RGBW node that is based on MySensors and works with domoticz (other controllers might send different strings => so you would have to change one part of the sketch).
    The sketch smoothly fades between colors and seemed to be stable in my test. What I still want to add is some kind of saved last values for possible restarts or loss of connection.

    I am gratefull for any feedback.

    Next I will finalize my (test) pcb design and order that.

  • i would like to test this RGWB also, are the PCB gerber files available ?

  • Hardware Contributor

    I was finally able to get my PCB designs done. They are currently being produced by

    I switched to big(ger) mosfets to be able to drive a longer LED strip and easier to use through hole components instead of SMD. My breadboard test worked great so I am really curious to see this in action.

    I also updated my github repo with the Target3001 based design, XGerber export and a eagle file export (although I am not really sure how that works, I never really used eagle myself).
    If you simply want to try these unchanged PCBs yourself here is a link where you can buy them:
    Although I warn you, they are not tested yet!

    Love to hear your feedback guys!

  • @LastSamurai

    Nice work! Do you have a BOM for the RGBW board?

  • @LastSamurai: I would also be really interested in the BOM!