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WiFi enabled multiplug

I really love these esp8266 modules, they allow me to automate my home for cheap. Some weeks ago I made a WiFi enabled multiplug, that can individually drive the 5 ports of a power bloc.

Introduction

As my home automation system progresses, I’m looking for new ways to control my appliances. I got a couple of RF controlled plugs, they are great and very cheap:

The downside of these devices is that they are really large, they take several spots on a multiplug and stick out quite a bit. It makes it almost impossible to control several plugs at the same place.

Here comes the solution, with my trusted esp8266 and a couple of relays, I should be able to modify a multiplug to separately control each plug on it. With WiFi of course!

Modifying the multiplug

first off, opening up a multiplug is not an easy task – it is NOT made to be opened. All of mine were using security screws, and I had to modify a screwdriver in order to remove the screws:

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Using my dremel, I cut a slot in the screwdriver in order to remove the security screws

Once open, the multiplug looks like this:

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on top you can see the ground metal bit, and on the bottom the two lines. My goal here is to cut the bottom one into 5 different pieces that would allow me to control each plug separately.

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cutting the line
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five separate pieces, I removed a bit of metal on each part so they wouldn’t seat too close to each other.

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The next step is about putting the pieces back into the case, for that I used plastic spacers and some hot glue.

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the height I need is roughly 1.5 spacer, as they are made of nylon I could just cut them using a knife.

 

 

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the adapted support with the groove for the metal bit

 

 

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Cleaning up a piece of the metal bit and put some solder on it, so the cable can be soldered on it

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Result, each bit is insulated and a wire is soldered and routed towards the back of the multiplug

After that I installed a vinyl sleeve for the cables so it looks nice and closed the multiplug back.

 

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At this point I have 7 cables going out of the plug, one “earth” one “neutral” and 5 “phases”.

The control board

Now that the multiplug is ready, let’s start on the control board, it will contain 5 relays, an esp8266 for the control part and finally a power module for the boards.

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Cutting a plexiglas piece that I will use as a support – using a knife to make a groove on it then breaking it works wonders!
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Checking out the layout of the components

The components I used are:

  • (top left) AC-DC power supply – gives you 5V/1.6A
  • (bottom left) DC-DC converter to convert 5V to 3V for the esp8266
  • (bottom, x2) logic level converters – they allow you to convert a 0/3.3v logic level to 0/5v – I ended using transistors instead.
  • (bottom right) the esp8266 WiFi module
  • (top right) the relay board, one with 4 ports and one with one port.
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gluing the two relay board together in order to use the holes form the board on the left to attach the relays to the plexiglas

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soldering the esp8266 + power module together
  • you can see the two 1×8 headers for the esp8266in the middle of the board
  • the header connected to the orange cables is to control the 5 relays

Now let’s install the spacers on the plexiglas:

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looking good – still using the logic converters (bottom PCB) that I will soon change for transistors.

Now that the board is ready, let’s program it so we can control the plugs individually.

Programming the board

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I use a similar structure for the software as for my other projects, check the GitHub project here: <link>

Final assembly

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The relay board acts as simple switches, so one pin is connected to the phase of the input. I used a metal ribbon to connect all these together.
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The other pin of the relay is then connected to a cable that will be connected to the multiplug
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Drilling the junction box to pass the cables
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soldering the cables from the control board to the multiplug

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Warning: I used “hearth” cable color (green/yellow) for a phase, this is extremely hazardous and should never happen – In the final version of this project I switched these cables for brown cable.

 

Next time I’ll write about the software and give some pictures of the final version.

 

 

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One Comment

  1. Jeff McDonald Jeff McDonald

    Love your work man. Keep it up! I’m working on similar stuff and appreciate the extra work to document.

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