Dot² - an Interactive Coffee Table





Introduction: Dot² - an Interactive Coffee Table

About: your best teacher is your last mistake !! - Dr. APJ Abdul Kalam

During my internship, I built an interactive Table on which you can run animations, some awesome LED Effects and yeah, Play old school games !!

I got inspiration to create this coffee table from crt4041's Music Visualiser Table

The table is controlled via a Bluetooth app developed using MIT App Inventor.

Let's Start building...!!

Step 1: What All Is Required ?

Hardware Stuff

  • Wooden Ply-Board (0.5" thick)
    • 4x - 8" by 28"
    • 1x - 28" by 28"
  • Foam-Board (around 10-11 sq. ft.)
  • Acrylic - Milky White - 28" by 28" 3mm
  • 4x Aluminium L-strip 29" Long
  • Self Tapping Screws (M4 will work)
  • Nails
  • Side Beading for tables
  • Solder

Electronic Stuff

  • Pixel LEDs ( or WS2811 Pixel Module) - 196 Bulbs.
  • Arduino Mega 2560
  • Bluetooth Module - HC-05/06
  • 330 ohm Resistor
  • 1x Zero PCB
  • Male Headers
  • Connecting Wire 5V 20A
  • Switching Power Supply

Tools Used

  • Circular Saw
  • Jig-Saw
  • Drilling Machine with 12mm Drill Bit
  • Screw-Driver
  • Hot Glue Gun
  • Soldering Iron
  • Dremel Rotary Tool (for finishing of grid)
  • Disc Sander
  • Precision Knife
  • Fevi-Bond (or SuperGlue)
  • Hammer

Step 2: Preparing Base for LEDs

Now Pick-up a 28" by 28" Ply-Board and make a uniform grid with each cell side measuring 2 inches.

Mark centre of each cell and START DRILLING...


Step 3: End the Drilling Madness...

After drilling all the way to 196 holes, now it's time to fix LEDs.

NOTE: Fix LEDs in the manner shown in above pictures else play around with software and code.

Now, Hot Glue LEDs onto Base Board.

Step 4: Software... Let's Make It Alive

There are two different softwares available to use it with


2. Custom Code with bluetooth added to hardware so that you can run 8-bit games on the table.

Step 5: Making Circuit for Pairing It With Mobile for Playing Games

To play games I designed a circuit involving Bluetooth module and Arduino Mega. This uses the app on phone to connect with table and use your mobile as controller for the table.

I've used PIN 6 as SIGNAL PIN to LED Strip. You can change as per your convenience but be sure you change that in Arduino code too !!

Then this setup was fixed on underside of table and electronics part is done.

Step 6: Coding Arduino

Use following attached files to download code for Arduino Mega 2560.

Note : Code will not work on Arduino Uno/Nano/Pro Mini/Micro as they all have 32B Flash but the required is more then 32 KB. is code involving Games and some animations for table control using mobile over bluetooth is for using table always being connected to a PC running GLEDIATOR Software

NOTE: If you want to use GLEDIATOR Software there is no boundation to use Arduino Mega 2560.

UPDATE : I have included libraries in below zip file names

Step 7: Time for a Test-Run

Test Run with couple of different Patterns using GLEDIATOR SOFTWARE and Arduino Code provided by GLEDIATOR.

Step 8: App for Controlling the Table

You can Download app from Google Play. In case, you want to alter the app you can always do that at MIT APP Inventor by importing the below attached .aia file.

Connect to your table and start playing...!!

Step 9: Cutting the GRID

I used 4mm White Foam Board for making the grid.

I marked 2 in. by 28 in. rectangles and using a table saw, I made 26 of them (13 for horizontal layout and 13 for vertical layout). Then using a jig-saw I made 4 mm wide equally spaced indents so that foam-board strips could be interlocked with each other forming a grid.

Step 10: Preparing the Outer Shell to Encase the Table Inside It

using 4x 8" by 28" 8mm Wood planks I prepared the boundary with support leaving 3" from the top inside the box to support the board mounted with LEDs. as shown in pictures and nailed them all together after applying sufficient amount of wood glue so they could bound more strongly.

Then slowly lowered down the grid inside the Box lit up to see everything still worked fine. Then to see if diffusion was good I placed Milky White Acrylic Sheet on top and everything worked as planned :D

For temporarily fixing the acrylic on top of table I used Aluminium L-Brackets to hold the Acrylic sheet in place

Step 11: Giving Table Final Look and a Base to Stand On.

A big thanks to Canvas of Dreams for helping me do this awesome wood work for the table. Do check out his channel guys !!

Side Beading for tables were sliced half and pasted and nailed onto the table's outer shell as shown in pictures. Then after they were dried 4 base legs were nailed to the table's base and a coat of PU Stain was applied to give it a final finish.

After everything was done a thin 2mm glass was laid on top of acrylic to prevent it from scratches and Coffee stains.

Step 12: Taa Daa It's Ready !!

Arduino Contest 2016

First Prize in the
Arduino Contest 2016

Remix Contest 2016

Runner Up in the
Remix Contest 2016



  • Casting Contest

    Casting Contest
  • Planter Challenge

    Planter Challenge
  • Make it Move Contest

    Make it Move Contest

We have a be nice policy.
Please be positive and constructive.




Hi there, I have uploaded the software but I am having a problem. The text is scrolling from right to left and back to front. Meaning that everything is inverted. Can you please point me in the right direction? Any kind of help would be greatly appreciated. Thanks

Could you give some examples of what exactly i can make it do? Like, can i play an old "pac-man" game, maybe leave messages for someone, make a phone call/text, watch videos from somewhere? I'm sorry, just not at all familiar with what some of the things it would be able to do. I'm so on the fence about making it! If it was possible to get it to do some things I'm really interested in, I'd Def build as it looks pretty nice even if it didn't have technology built in! Oh, one last thing, can you upgrade to anything in the future? Thanks, and really nice instructable too!!

2 replies

ypu can play animations, use it as VU Meter, play games such as snake, tetris, pong, bricks or even use it as a dice if playing board games. yes you can add more 8 bit games in future

Has there been any update about adding games or new features (specifically sensing where things laying on top of the table are)?

I was thinking of reducing the number of LEDs from 196 to 144 (getting rid of the outermost square) and a couple of these

Where would I change the number of LEDs that the app thinks the table has?
And would it be possible to tap into the same power source as the LEDs for the wireless chargers?

In Step #3, to drill all the holes for the LEDs, I used a piece of PEG Board, that had the holes, at 1 inch on center.

Hey akshay
I want a pic of your glediator output page please can you send me??

I figured many things out on my own. Unfortunately, this Instructable while it looks great has some incomplete information that may get a beginner such as myself into trouble. I spent countless hours researching only to find out there were problems with both the code and construction of this build, or information was simply missing. Either way, after many trials and errors, I've made a table to call my own. I may post an instructable of my table that is a little more suited to beginners, but would still like to thank you for giving me a starting point and for sharing.

hey Baweja - any idea how to get more games and programs for the table?

There is a fatal flaw in the dimensions of this table. You reference needing four 8" x 28" and one 28" x 28" pieces of plywood, and make a box with the four pieces. Then try to fit the 28" x 28" board w lights inside the 28" hole. It does not fit in but sits on top. Your actual measurements used on your table must be different, otherwise it is impossible the board fits inside.

2 replies

hey thanks for pointing that out it was 4x 8" by 29"

One last question - you stated in the section on Arduino software that your signal pin was set to pin 6 and needed to be changed if a different pin is used. How do you change the pin in the code? Is it in the LED-Table sketch under where it says "FAST_LED_DATA_PIN"? It looks like it was set to 8 but I can change it if that's the only place I need to change. Thanks

i am not extremely confident in making circuits - do you have any better pictures of the circuit board configuration? I already bought all of the materials to make this (over $200) but i want to make sure i set up my circuit correctly and the actual connections with the arduino and the breadboard, as well as the wiring to connect the LED and power supply isn't shown in your pictures.. :( can you PLEASE render some help??


7 replies

i have given schematic above please check

is this the schematic (1st image i posted) or did you upload another one? im sorry about asking so many questions and I appreciate your responses. but to make the connections as in the diagram above, do i just use 22 awg wire and solder? and the cord that you have in this picture:

is this the LED power cord (in the second picture)? Did you have to purchase that seperately from the Power supply and LEDs? also, is the Arduino on the underside of that breadboard?

Thanks again for your help!! This table rocks

bluetooth cord.jpgSchematic.jpg

Hey, you can use 22 awg wire directly also or make circuit on proto board.

and that connecter is for WS2811 LEDs and yes Arduino goes under this proto board.

Thanks for that info. And one more electrical question - the soldering shown in your picture, is that the same pcb board with the arduino on it or did you make another circuit? Did you just solder all the male headers in place on the pcb for the LED power cables (female), the HC-05 and the Arduino?

Almost there! last question, your schematic shows the 5V and Ground on the HC-05 being connected to the same on the Arduino Mega. That is referring to the 5v and Gnd connections on the digital section of the Arduino, correct? I was thinking something like that would go in the communication section but i'm new to this and I don't see a 5v or Gnd in the communication area. Thanks!

5V and ground are in power section on left side of arduino mega above analog section