DIY Interactive LED Coffee Table – Arduino Project

Today on Creativity Hero Channel I'mgoing to make an interactive LED coffee table.

This unique coffee table cancreate beautiful atmosphere and will be real focal point in my living room.

Iwanted to make a simple design with some interesting features that will take myroom to a whole new level.

It is controlled via a custom-made Androidapplication so I can easily change the reactive color, or the background color, and I can even adjust the brightness.

The table is made out of MDF for the box, apine for the legs, a glass top, and its inner part consists of an Arduino board, a Bluetooth module, some LEDs, proximity sensors, and a bunch of wires.

This is avery challenging project, but with hard work and patience anyone can build it.

Here I'll show you the entire process of building, wiring, and connecting all thepieces together.

Now let's start with the build.

First I'm cutting all the piecesto size on my table saw.

I'm going to make a box out of MDF.

I'm using a 10millimeters thick MDF for the sides and the 8 millimeters thick MDF for thebottom.

Most of the pieces I cut using my table saw fence, but for the largerpieces I clamped down a scrap wood as a guide, because the fence is prettywide and couldn't be secured to my workbench.

Inside the box I'll create agrid out of MDF, so I need to cut 12 pieces 4 centimetres wide.

For the legsand the frame below the box I used a large pine board.

You can notice that itis warped, but I don't have a planer which means I need to make a lot of cutsand adjustments on the blade and the fence in order to flatten all the pieces.

It took me some time until I finished, but finally I got nice and smooth stripsall with the same width.

To cut all the pieces to the right lengthI used the crosscut sled.

For making repeated cuts I mounted a stop block.

Some of the pieces were much longer andI needed to make another stop block.

I set the fence and clamped a scrap ofplywood on it, which will actually serve as a stop block for the longer pieces.

For the grid that I previously mentioned I should make dadoes onto each MDF piece so that they can easily lock together and make a perfectly squared grid.

So, Imarked all the points for the dadoes, wrapped the pieces together with amasking tape, set my blade on the appropriate height, and made all the cuts.

They were very easy and fun to make.

All the dimensions for this table can befound in the video description.

There I also put links to all the tools and thematerials needed for this project.

Once I'm done with all the cuts I can move onto sanding.

I started with 80 grit sandpaper and then continued with 120grit until everything was nice and smooth.

First I assembled the box.

I applied a nice amount of wood glue and joined thepieces together with corner clamps and a band clamp to make stronger connection.

Between the sides of this frame I added a small piece of wood in each corner andsecured them well.

After that, I can secure the bottom of the table with a woodglue and a lot of screws to make sure it is firmly attached.

I pre-drilled holesand then inserted countersunk screws.

In order to avoid any gaps I'm applyinga wood filler on the joining parts of the table.

While the wood filler wasdrying I made two openings on the bottom of the table, one for the high voltagecable and other for the switch.

Using a rasp I made the opening for the switch aperfect fit.

When I placed the smaller MDF board into this box I noticed that itwas warped in the middle due to its length, so I added two more small woodenpieces into the box for better support.

Then I measured the depth of the box andalso realized that I should add extra 8 millimeters height onto thosesmall wooden pieces so that when I finally place the glass on the top itwould be flush with the sides.

Fortunately I had8 millimeters thick MDF, which is perfect for this purpose.

I cutsix small pieces of it and glued them on the top of the pieces that I previouslyattached.

I fine-sanded the MDF to remove the extra wood filler and prepareit for painting.

Then, I wiped the dust off of the surface with a wet rag.

I don'thave to paint the entire inner part of the table, so I applied a masking tape onthe sides to get straight, clean paint lines.

After that I applied an oil-basedprimer using a roller for large surfaces and a brush for the areas that are hardto reach.

I left it to dry overnight and sanded the surface with my orbitalsander using 120 grit sandpaper.

Now it is time to apply paint.

I chose anoil-based white paint and carefully applied it on the surface making sure Icover every part of the table.

While it was drying I moved on to the legs andthe frame below the table.

I will join them together with pocket hole screws.

The pocket hole jig that I have is very useful and easily adjustable tool formaking pocket holes.

I wasn't able to make two pocket holes on each side dueto the width of the strips, but later I can mount corner brackets if needed.

Before attaching the screws, I'm applying a wood glue for stronger connection.

thenI'm driving the screws in.

In order to make the pocket holes invisible Iinserted the screws on the top of the frame.

It was a bit complex step becauseeverything has to be square but I succeeded with a little effortand focus on my work.

Again, I applied a wood filler into the gaps and left it todry.

Then, sanded the excess to prepare it for staining.

When it comes to thestain, I applied a rosewood stain to get a nice contrast between the top andthe legs.

I did the same in my previous project and it turned out wonderful.

Allthe pieces that will be used for the grid inside the table I painted white aswell.

What's left to do is to join the two parts of the table together.

I clamped the top with the bottom, pre-drilled holes with a countersinkdrill bit, and then used a lot of screws to secure them together.

OK, now I canmove on to the electronics part.

The electronic parts that I'm using areaddressable LEDs, infrared proximity sensors, an Arduino Mega board, aBluetooth module, 5V power supply, and a bunch of wires.

So, first I'm usingthis template to drill three holes into each square and onto each square I willinsert an LED and a proximity sensor and connect them with some wires.

I willattach everything onto this MDF board.

It will be divided into 45 squares.

Then, Icut 45 LEDs into individual pieces.

From this strip I need to cut 5 centimeterslong pieces of red and black wire and strip off around 5 millimeters of theinsulation on their ends.

I'll use one pair of those for each LED and anotherpair for each proximity sensor.

I'm doing the same with this green wire, but hereI'm cutting longer pieces and also stripping off their ends.

Then, I amsoldering the wires onto the LEDs.

The black and the red I am soldiering on the Ground and the 5V pad, and the green one in themiddle, or the Data IN pad.

After that, I can move on to the proximity sensors.

Iseparated the Infrared transmitter and the receiver and made a larger distancebetween them.

In a normal position the sensor won't be able to detect the glasson top of the table, because the glass won't reflect the Infrared light.

In thisway, I can position the transmitter and the receiver at an angle so that thelight can be reflected to the receiver on the other side.

So, I am removing thetransmitter and soldering it back on the sensor, but this time with 4centimeters long wires.

I used single core wires from an Ethernet cable, because they can be easily bent and stay in that position.

On the other side ofthe sensor I need to solder the black and the red wire to the Ground and 5V pin, and a longer gray wire to the Output pin that will connectsensor to the Arduino board.

These are pin headers that I need to solder ontothe longer wire ends, so they can be easily inserted into the Arduino board.

Toinsulate them I'm using a shrink tube and a lighter.

I repeated this step 45times.

Here you can see all the LEDs and the sensors ready to be attached ontothe MDF board.

The LEDs are the first to be attached onto the board.

I insertedthem into the holes that I previously drilled, peeled off the tape cover on theback and stuck them onto the board.

Then, I connected them by soldering the greenwire in the middle of each LED or the data OUT pad of the previous led to thedata IN pad of the next LED.

Once I'm done with the LEDs I'll do the same withthe proximity sensors.

This time I'll hot glue them next to the LEDs.

Here I needto pay attention to the length of the gray wires.

All of them will be insertedinto the Arduino board, which will be positioned in the middle of the back sideof the board.

So, the cables that are further from the Arduino boardare longer, and as they're coming closer to it, they become shorter.

Yyou can findthe exact dimensions that I used on the website article.

The Infrared transmitterand the receiver need to be placed facing up, so I'mmaking some adjustments here.

Now, I will turn the MDF board to the back andconnect all the wires.

I'll start with hot gluing copper wires along with thelength of the board.

They will be used as power lines for the LEDs and theproximity sensors.

On the first line I'll solder all the red wires and on theother line all black wires.

Before soldering, I need to remove theinsulation off of the copper wires with a sandpaper, otherwise I won't be ableto solder them.

It took me a long time until Ifinished soldiering all the wires.

At the end, I connected all the positive and allthe negative lines.

Also, on these lines I soldered two more wires which I'll laterconnect to the power supply.

I added 330 ohms resistor between thefirst LED and the Arduino to reduce the noise on that line.

All the wires areready, so I carefully insert them into the Arduino board in order.

Here I'm alsoinserting the Bluetooth module.

This is the complete circuit schematic where youcan see how I connected everything together.

For more details on how to usethe Arduino in combination with this addressable LEDs and the Bluetoothdevice you can check Dejan Nedelkovski YouTube channel and his website HowToMechatronics.


He made a tutorial on how everything works, including thesource code of the program and the custom-built Android application.

I'llput a link to his video and article in the description below.

Dejan makes awesome videos in the area of Mechatronics, providing complete explanation, circuitschematics and source codes.

Before mounting the power supply, I made acontinuity test on the circuit using a multimeter.

The multimeter didn't beepwhich meant my connections were all good.

now that I'm done with it, I can mount the 5V power supply on the bottom of the table.

It needs to beraised up just a little to get better air flow.

Therefore, I glued two pieces ofMDF and placed the power supply above them.

Then, I pulled the switch in and themain power cord into the appropriate holes, and connected them to the powersupply.

4 meters of the cord is enough for my space, so I cut it to size andwired aplug on its end.

After that, I brought the MDF panel and connected thelast two wires into the power supply.

At this point, we're ready to program theArduino.

The code is fairly simple, it just reads the proximity sensor and ifan object is detected it lights up the particular LED.

For the color andbrightness control we use the custom-built Android application.

Thedata coming from the smartphone is received via the ArduinoBluetooth module.

As I mentioned earlier, you can find detailed explanation on howthis code works on Dejan's article.

Once I uploaded the code I placed the panelinside the table.

I noticed here that the power indication LED of the proximitysensors would interfere with the main LED light, so I covered them with anelectrical tape.

Making the grid is very easy, I just need to lock all the partstogether, and as you can see they fit snugly.

Finally I can put the matte glasson the top of the table, turn the switch on and check if everything worksproperly.

One of the LEDs doesn't turn on when I place a glass on top of it, so Iremoved the glass and adjusted the transmitter.

It needs to be positioned ata right angle to be able to reflect the light to the receiver.

Now I can say thatI'm finally done with this project.

This interactive coffee table turned outperfect.

I like every part of it, including the design, the color change andthe brightness adjustment.

It gives another dimension to my living room.

Thanks for watching.

I hope you enjoyed this amazing DIY project.

If you likethis video give me a thumbs up, leave a comment down below and subscribe to mychannel.


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