Introduction: Smart Home Power Strip

Picture of Smart Home Power Strip

Smart Home Power Strip is an android and/or iDevice controllable plug outlet. You can turn the individual outlets by taping a button from your gadgets. I spend about $32 making this project.

Difficulty level: Medium (Basic electronics and soldering skills required)

Time needed: A weekend

Disclaimer: This project involves voltages 110-220V which is dangerous. You must be very careful doing this work. Please do not proceed if you don't take safe measure while working with it. Make this at your own risk.

Step 1: Things You'll Need

Picture of Things You'll Need

You can buy these stuff from your local electronic store:

2 pin terminal block (x5)

Resistor 220 Ω (x4)

5V relay 5 pin (x4)

5mm LED (x4)

Blank PCB 2.5 inch x 4.5 inch or larger (x1)

Female Header 40 pin (x1)

Female-female jumper cables (x6)

fiber cable (2 meters)

You can buy these stuff from amazon or other online shop:

HM-10 (x1) or HC-05 (x1)*

Arduino Pro Mini 5V (x1)

FT232RL FTDI USB to TTL Serial Adapter Module (x1)

You can buy these stuff from your local chemical store:

H2O2 500ml (x1)

HCl 500ml (x1)

**You can buy these from your local hardware store:

M. 3 X 60 Screw (x4)

M. 3 P0.50 Nut (x8)

M5 X 20 Spacer (x8)

2mm acrylic sheet (x1)

4 plug outlet electric socket*** (x1)

You can recycle from your used phone charger:

DC Power Supply (will be explained more in step 4)

*You must use HM-10 if you want to use iDevices

**You can replace all the materials here with a prototyping box except for the electric socket

***The electric socket must have a switch for each plug outlet

Step 2: Making/Etching Your PCB

Picture of Making/Etching Your PCB
  1. Cut your PCB board to 6.7cm x 12cm.
  2. Print the PCB design using laser printer on a glossy paper.
  3. Place the paper with the PCB board.
  4. Press using an iron or a laminator.
  5. Etch the PCB

I used Hydrochloric acid + Hydrogen peroxide to etch my PCB. I'm not going to explain this step in detail, but you can check this instructable (not mine) if you never etch your own PCB.

Step 3: Drill the PCB and Solder the Electronic Components

Picture of Drill the PCB and Solder the Electronic Components
  1. Using a mini drill, drill all the holes on your PCB, I recommend using 0.8mm or 1mm drill bit.
  2. After you finish drilling you should solder all the electronic components, header pin, and some jumper cables.

Soldering small electronic components to a PCB can be quite frustrating for beginners. Here is a guide to soldering:

Step 4: Finding the Right Power Supply for Arduino

Picture of Finding the Right Power Supply for Arduino
  1. You can find the power supply from your old phone charger or from other power supply unit.
  2. The power supply should have 5V Voltage output. The current can be 750mA or even better if you have 1000mA.
  3. Use a saw to open the Power Supply enclosure.

Step 5: Plug Your Arduino Pro Mini and Bluetooth Module to the PCB

Picture of Plug Your Arduino Pro Mini and Bluetooth Module to the PCB

Before placing the bluetooth module, you should bend the pins first.

  1. Bend the pins one by one using pliers. Be careful not to break the pins (I accidentally broke mine).
  2. Plug the Arduino Pro Mini and bluetooth module to the female header.

Step 6: Programming Your Arduino

Picture of Programming Your Arduino
  1. Connect your Arduino to your computer using USB to TTL.
  2. Upload the arduino code.

Step 7: Hacking the Electric Socket and Power Supply

Picture of Hacking the Electric Socket and Power Supply
  1. Open the electric socket screws. The relay from your PCB will not replace the function of the switch from the electric socket. In my picture, when the switch is on, the pins (the one I drew with a line) will be connected. If you connect the two pins from the AC input, there will be a short circuit (That's dangerous), so you cannot connect those pins. You can solder one of the pins directly to the output as shown in the next picture.
  2. Next, you'll need to drill 2 holes (between 1st and 2nd switch and between 3rd and 4th switch) for the cables to go out from the electric socket. solder the remaining pins to a cable, and connect it to the terminal block on your PCB (Please be careful not too screw the cables to the wrong place).
  3. Drill one more hole and solder a cable to each pin from the 220V input. Solder the cables to the power supply input. Solder two cables to the power supply output and screw them to the terminal block to power the Arduino. Screw the positive pin from the power supply to the positive terminal block. Screw the negative pin from the power supply to the negative terminal block.
  4. Don't forget to screw back the electric socket.

Step 8: Making the Enclosure

Picture of Making the Enclosure

Steps to make acrylic enclosure:

  1. Laser cut your acrylic using the given .eps file
  2. Insert four screws to the acrylic holes.
  3. Tighten the screws using nut. Use the screws from the acrylic and mark the PCB (The curvy part near the relay terminal block and the other cut part near the bluetooth module).
  4. Drill the holes on the marked PCB.
  5. Insert the screws to the holes.
  6. Insert nut and a spacer to each screws.
  7. Insert another acrylic and tape the power supply to the acrylic.
  8. Follow the same pattern. Your enclosure should look like mine.

Using this acrylic enclosure, the project will not be fully enclosed. This project involves high voltages, for safety reasons it is highly recommended to use a fully enclosed case. Only use the acrylic enclosure if you are sure about all the electronics connections.

If you want to use fully enclosed case, you'll need to find a prototyping box with suitable size and drill holes for the cables.

Step 9: Using Your Android Device

Picture of Using Your Android Device
  1. Download the app: Arduino Bluetooth Controller.
  2. Connect/pair your Android device to your bluetooth module.
  3. Open the app
  4. Open terminal
  5. *Press 1 to turn on switch one, press 2 to turn on switch two, and so on...
  6. *Press 5 to turn off switch one, press 6 to turn off switch two, and so on...

*Press enter after you press the number, you can turn on/off several switches at once.

Step 10: Bonus Mod Ideas

Picture of Bonus Mod Ideas
  1. More relays
  2. Voice activated
  3. Control over wifi
  4. Sensors

Have fun ;)


TarekM2 made it! (author)2016-07-17


terralenaire (author)2015-07-18

Amazing !!!

I plan on making the same Power strip setup for my Design Project so I can use your help / idea on some stuff

The idea is fighting energy vampire / standby power via power strips with timer

So I'm planning on using a timer instead of a remote ...

Question is :

Can it act as a power strip for home type aircon (or raise the relay capacity) ?


Yes it can act as a power strip for home type aircon, but I think typical home type aircons uses ir remote to turn it on and off.

Good luck with your project ;)

mprastyo (author)2015-07-15

Habis berapa gan?

eric dirgahayu (author)2015-07-10

Selamat...First Prize...loh...:D amazing

Makasih gan ;)

primosanch (author)2015-07-07

Too awesome. Thanks for sharing.


EugeneM5 (author)2015-07-01

I'm choosing parts to implement pretty similar solution with wifi instead of BT. So I've found power strip with 5V psu on board and some free space inside to put controller and relays. Brand is local, but most probably it's available worldwide

Great! I also planned to make full home automation and control it over wifi. Good luck with your project!

P.S. You can send me pics or private message me when you finish your project ;)

agulesin (author)2015-07-01

Oh, just a point about the laminator used to make the PCB: Someone has taken the cover off (no doubt to unblock it when things get wrapped around the rollers!); this is a bit dangerous as there is a very hot heater between the rollers, if anyone touches that they would get a serious burn. I recommend you put that top cover back on ASAP! Be safe, live to write another 'able! :-)

Actually I don't have my own laminator, I borrowed that from someone. I just realised that it has no cover. I will remind the owner to put the cover back.

Thanks for the consideration!

agulesin (author)2015-06-30

A nice project and well explained, deserves my vote! :-)

Just a point about the socket; you state "***The electric socket must have a switch for each plug outlet" but I don't think that's necessary. After all, that type is very rare (here!). What you could do is cut the busbars joining each socket of a conventional socket strip, and solder the wires to each socket individually. I assume the switches are unused in the final project anyway, so are in fact wasted.

Thanks for the vote and advice!

Yep, actually it is not necessary to use an electric socket with switch for each outlet, but it will be much easier than using the one without the switch. Cutting the busbars keep them in place and inducted is not easy. The switches are not wasted, you can still use the switch to turn it on and off manually (without BT and gadget).

Raphango (author)2015-06-30

Great ible! Thanks!


bhermance (author)2015-06-28

This is awesome but intimidating. I am not an electronic genius. I may try this one day when I think I can do it! This is something I always wanted!!

Thanks, you should try make one!

raptor_demon (author)2015-06-26

cool idea, but i would strongly advise that any mains 110v/220v be fully enclosed to prevent fingers and other things ending up in the wrong place.

Thanks for the advice, really appreciate it ;)

Yep, 110V/220V could be really dangerous, but I think the acrylic has covered all the prone-accident and high voltage areas. It is still safer to use full cover enclosure though.

When it comes to "high voltage" anything above 50VDC 60VAC(I am German) you should know about liability. Are you sure that noone ever will treat your device like any commercial line Voltage stuff? E.G. go with an damp cloth over it to remove the dust?

of course not!!

Don't let me talk about fire hazard...but a little bit.

The distances (4mm) from high to low voltage someone already mentioned are nessecary. In your special case here, no connections to the outside, because of wifi no switches or potis, it would not even matter for electric shock to people. Symply for fitre hazard.

But your construction is only allowed in a casing which is restricted to qualified personal only. This single isolated AC wires to the"

4 plug outlet electric socket

" are not allowed outside of an enclosure, make an casing for all together so that only"qualified Personal"(you) has acces to the wiring.

Another thing is the single pole relay,( I hope you simply bent away the other ones). You see the switches on the power outlet? they switch both phases, you !!!must!! do the same. Simple reason: because you can plug the AC in any direction you choose, it is not ensured that the "hot" wire AC is interrupted by your relay. So your 2 wire 230VAC lamp is of but has still 230VAC to ground, if there is a damaged cable "connected" to the lamp housing you get zapped, and you will not let this happen to another person.

Btw: Lmecano mentioned not to solder at 230VAC, that is only somewhat true. You can do it all along. You can see it in the AC wall plug you have opened ;-) . True is you should never tin the blank ends of the wires you put into your "

2 pin terminal block (x5)" the tin creeps slowly, a resistance builts up and it burns! professionels use tiny metal tubes in which the blank filaments are put and then crimped(I learned the hard way to always! crimp).

Modern clamps, nowaday are accessible, which use a spring that is opened by pressing a srewdriver in, when the srewdriver is released the spring gives a constant pressure to the contacts around the wire, so you can eve use a tinned wire ;-). no that would be Bullshit, but it is possible.

I think these "Lüsterklemmen" (German: Lüster this old lighting constructions with lots of Glas prisms that reaaly needed a hook in the ceiling for 75kg load), are symply sold for us stupid DIY idiots who don't know better. Electricians use spring loaded clamps for house wiring, for which you even dont need a tool, you push the !single! wire(yours won't work ) in and that was it.

Nicely done for the rest of your construction, but when you use 230-110V always have a disclaimer that you take no warranty whatsorever etc. You will find them all over the place, and when I read the comments her a disclaimer is very much needed.


Thank you for the advice!

This is my first time making project involving high voltage. I'll consider more safety for my next project involving high voltage. I'll add more distance from high to low voltage, add full project enclosure, and use clamp with screw for high voltage.

P.S. I have added disclaimer

alfij (author)2015-06-29

Great effort but you can spare most of the work done and make it even cheaper, see link = less than 4$ module.

I would consider putting the relays + power supply into power socket case, this way you'll have to connect only 6 wire (of low voltage!) between high voltage and low voltage cases.

Four 4 Channel Relay Module DC 5V With Optocoupler For Arduino PIC ARM AVR DSP

Samuel_Alexander (author)alfij2015-06-29

Yep, I have seen those kinds of relay module. I decided to make my own, so I can directly add the arduino pro mini to the PCB.

Thanks for the input :)

gtoal (author)2015-06-28

Have you seen these? - they'll switch 120V AC and you should be able to drive them from an arduino with a wireless module as well as from the manual remote control. (wireless modules similar to or ) (The cost for those parts should be under $20 total.)

Samuel_Alexander (author)gtoal2015-06-29

Thanks, I think I'll try them for my next project!

Stelu (author)2015-06-27

Best Instructable of this type ever seen since I heard about Instructables. Surely blew my mind and make me think very serious to do one of this! Good, very good job! Cheers from Romania! :)

Samuel_Alexander (author)Stelu2015-06-29

Thanks! You should try make one ;)

sekolahrobot (author)2015-06-28

wow,... good job


Lmecano (author)2015-06-26

I love the concept, I will probably build one.

As said raptor_demon, you can't leave a product with the wire visible, you need to do a BIG box to cover everything, your life worth it.

MOREOVER ! NEVER sold on 220V ! Why ? If something creates a short-circuit, the welds are going to melt and I let you imagine the next.

HerbertD1 (author)Lmecano2015-06-28

Solder not weld, welding would be oK but not practical ;-) read may othe comment.

Samuel_Alexander (author)Lmecano2015-06-26

Yep, I will probably fix my project as soon as I found a suitable prototyping box (or maybe I will 3D print one). That thing you said about short circuit, that's so horrible. I wouldn't want anyone gets electrocuted because of this project, really thankful for the comment!

macwizard3 (author)2015-06-28

How would any of these components change if using an American 110v power outlet strip?

You don't need to change anything if you use 110v power outlet. Typical power supply can input from 100-240v. Hope this helps :)

nqtronix (author)2015-06-27

Out of all the PCBs made here yours definitly belong into to the best 10%. The component placement is nice and tidy, the traces bend nicely in 45° angles and very few jumper links are used. It simply looks professional.

However for your next design I'd recommend to increase the spacing between the mais conncetions and any wire/ trace in the low voltage digital section to at least 5mm, 8mm if you can. In this case it isn't dangerous but imagine having a button attached: If for any reason, the humidity of the air might be enough, the mains connection might be directly connected to that button you risk a severe electric shock. Again, in this circuit it's fine, you're controlling it wireless anyway. It's also worth mentioning that you've done a great job isolating the power supply from the circuit, the second layer of acrylic glass is simple but effective!

It seems to me like you're aiming high, so here are a few more hints for your next PCB. Of course this is nit-picking and mostly cosmetic, but hey, it might be useful sometime:

The traces for the mains could be wider. They are like 2mm wide, thus they can carry roughly 4A without significant heating, which is enough for practical everything. Nevertheless it's a good practice to design electronics for the worst case:

I've marked a few things on the board:

green: The traces could be a little shorter, it reduces the resistance and inductance. The effect is minimal, it adds up.

red: The distance from copper to copper should be increased. On the main connections for safety reasons, at the other spots it might be aesier to etch and solder without shorts.

blue: It is recommneded to avoid sharp inward corners due to the eaching process. It's only noticable with smaller traces but the etching solution might get "trapped" in those places, eventually dissolving parts of the trace.

One final request: Could you please add shematice and the board as a pdf for non-eagle users? I don't want to install a programm just to be able to see that. Thanks :)

Thanks for the input!

This is my first time designing and etching my own PCB, I usually just make project prototypes using breadboard. I will keep sharpening my skills and hopefully I can make better PCB design in the future. I will fix the "Smart_Home" PCB design according to your input soon. Once again thank you sooo much for your input.

P.S. I have uploaded the PDF PCB design as you requested

Thanks for the PDF! And nevertheless, for your first PCB this is impressive ;) I can't wait to see what you come up next with.

Thanks! Stay tuned for my next project ;)

norben (author)2015-06-27

Good job.thank you.

Samuel_Alexander (author)norben2015-06-27

Your welcome ;)

jallson (author)2015-06-26

Add voice activated will be cool.

Samuel_Alexander (author)jallson2015-06-26

Coming soon ;)

do u have a laser cutter... i want your help in building a sub 100$ 3d printer and will open-source it

I don't have my own laser cutter, but there is a place that provides laser cutting service near where I live.

how much does it cost to u. for 3 mm mdf per squarefeet

samalert (author)2015-06-26

When i was your age i dont know what i was doing, but as far as i can remember it was not as awesome as you are doing. Very commendable man !

Just a piece of advice as many have already pointed box it and insulate it. (Even though they are but dangling wires does not look aesthetically pleasing, and when voltage is high they dont look safe.)

Thanks man! Yes I will box it and make sure that all high voltage components will be insulated ;)

About This Instructable




Bio: I am Samuel Alexander, a 11th grade student at Cita-Hati High School in Surabaya, Indonesia. Since I was kid I have been interested in making ... More »
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