In wall - PCB, (AC to DC 5v)

[m26872]

I agree with @martinhjelmare I just assumed there would be some other insulation and it would be the second step of the design. Good you cleared this out early.
I think it is almost possible, but really hard, to copy the size and shape of commercial in-wall devices and still fit in all we want. Small customized PSUs may be necessary.
Personally I'd prefer external boxes. They could be in wall as well, as long as there's space for safe (diy) designs or even future projects.

[martinhjelmare]

I'm thinking I'd like to try and design a custom box for 3d printing that could fit this project by @sundberg84 and also fit inside the wall box. Has this been done already and do you think it's worthwhile, i.e. is it possible?

[sundberg84]

What I know of, this has not been done before... not the PCB or the 3d printing.
Good points taken above! We need to consider this and this might not be the optimal design.
Maybe thought was that this design can break some ground and maybe it can lead to better and even smaller designs.

I like my designs easy :) Pro Minis with ready bootloaders so everyone can be inluded, but this might not be possible...
I will still finish my design and see how it looks.

[yancym]

Hey everyone. Been following this as I'm very interested in having this functionality with the Arduino's. I'm a newbie and have very limited knowledge with anything electrical, so forgive my ignorance. How is this problem any different than what the X10/ZWave/etc. solutions have already overcome years ago? I have an X10 wall socket that does very similar switching on/off of one socket. All the components are built inside the socket, putting the control components and the high voltage very close together. The wall switches are another example. They always have some current running thru them even when the light is switched off, to detect the signal. Again, forgive my lack of understanding how all this works, but it seems like this may not be as big of an issue as I'm reading here. Thanks.

[Samuel235]

Some awesome input here for @sundberg84's project! I would love to see your designs completed whether or not they suit other people's situations dude. Once you have completed yours then we can build from your base to create another product that would suit others. Note i said build ANOTHER product, not upgrade yours. Your's would be widely used by others, just not the ones that need it inside of a UK Sized box maybe. So, most importantly, lets help develop yours and help test it if needed.

I'm going to be doing some basic designs on getting a battery powered one installed into a UK socket as my next major development in my network, so we might have a starting point by the time yours is nearing completion.

If you need any input/help/testing just give us a shout ;)

[martinhjelmare]

I started a new thread for my attempt at a custom box design.
http://forum.mysensors.org/topic/2509/box-for-in-wall-pcb

[Samuel235]

I have also started my own thread to save me clogging your development thread up @sundberg84. I'm hoping that we can gather seperate ideas and then discuss to develop products that are a creation of many of opinions/improvements.

[sundberg84]

I recieved my PCB today - Yea!

The good news is - its working, and it fits inside my wall socket.
The bad news is that as always i will need another revision - the hole for the fuses are to close to each other.

Some pictures:

Anyone with any input on this?

[Samuel235]

@sundberg84 Fantastic news on receiving this before the Christmas dull in mailing! Super happy for you to receive, populate and get working your custom board dude! I have no input other than to congratulate you on a successful board, shame on the fuse issue :( Could i ask you, do you have any components sitting under your nRF module?

I'm currently having a few little teething issues on getting the board down in size slightly, it should fit my application as it is right now, but i would like it a little smaller. The thing that is really holding me back on sizing is the screw terminal being a 4 pos block. I might have to reset to maybe 2 x two pos, or even some singles. Although i only need two switches on this particular application, i would like to make it accept 3 so just in case i install a 3 way switch somewhere, i am able to use this board, rather than creating another.

Hopefully I'm not too far away from completion now.

[martinhjelmare]

Nice! Good images, and thanks for the scale. Is your wall box also 4 cm deep, like the ones I have in my house?

[Łukasz Rybak]

Hi all,
It looks very good @sundberg84, It's still a little bit bigger than fibaro switch but costs much much less :) Looking forward to see your next revision

Is it any chance to place another screw terminal to allow turn on/off not only via radio but with the local button as well?
From other side as a workaround it still should be possible to hard soldering some wires to appropriate pin on arduino side.

I'm wondering why some Asia manufacturer is not able to build a tiny pcb with integrated arduino, nrf radio, ac-dc trafo and relay on one single board to keep small footprint.

[m26872]

@sundberg84 Good job and nice fit! Looks like you can even make the discussed separate box-in-box for it if you like.
Do you have a BOM of the parts you used this far? And which ones you need to replace or move around.

[sundberg84]

@samuel235 - No components between the NRF and the PCB but yes, if you mean on the other side of the pcb. There is the 5->3.3v converter and caps.

@martinhjelmare - Yes, 4.5cm it seems but there is some room on the sides so i hope to be able to squise in a relay.

@łukasz-rybak - You can connect a local button between d3 and gnd on the MYSX connector on the right side. This can read the switch and change a relay depending on what state the switch is in.

@m26872 - Yea, lets hope so... ill do another revision of the board and lets see where this ends up.

[sundberg84]

So, my rev 3 is coming along:

• moved the Dallas temp sensor
• added some more space for the 240v fuses:
• labels changed

The BOM? Is that the parts used?
I have used what we concluded here:
http://forum.mysensors.org/topic/1607/safe-in-wall-ac-to-dc-transformers

This is what i bought (no garantees given this works/doesnt burn)

HKL-PM01 http://www.ebay.com/sch/sis.html?_nkw=HLK-PM01+AC-DC+220V+to+5V+Step-Down+Power+Supply+Module+Household+Switch+Q15274&_id=351418782712&&_trksid=p2057872.m2749.l2658
(DO NOT BUY THIS!!)Fuse http://www.ebay.com/itm/111433875797?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Thermal Fuse http://www.ebay.com/itm/221560426284?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Varistor http://www.ebay.com/itm/260848704608?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Pro Mini 5v
Nrf radio
LE33a http://www.ebay.com/itm/400691492273?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[Samuel235]

@sundberg84 said:

@samuel235 - No components between the NRF and the PCB but yes, if you mean on the other side of the pcb. There is the 5->3.3v converter and caps.

Just to let you know, I meant in between the nRF board and the PCB, so thank you for letting me know :)

Rev 3 is looking pretty neat and tidy if i must say so. Keep up the awesome design work, I'm learning off of you, thank you! ;)

[m26872]

@sundberg84 Yes, the BOM is the list of all components that populates your PCB. References, values, source and all other specifications that the "manufacturer" will need.

I was actually mostly interested in the fuse looking like a big diode in your picture. Is it ordered from that link you showed? Which value is it?

[sundberg84]

@m26872 Its the slow blow fuse, and I ordered 240v, dont remember which current and that is offcourse whats interesting. On a business trip but can check this weekend when i get home. The datasheet for the HLK refers to:

Maximum input current ≤0.2 A
Input current surge ； ≤10 A

[bjacobse]

Maybe you should add a ground plane on the low voltage part of your design on both sides, but avoid the area where the NRF24L01+ antenna is placed

[Samuel235]

@sundberg84 Could I ask where you order your boards from, which manufacturer do you use and would you recommend them?

[sundberg84]

I order from itead. Works great and good quality.