Introduction: Decorative LED Table Top
Hello! This is my first project for my Interactive Design
class where I play upon the Light Up Disco Table decoration by turning it into a prototype for an Interactive game using a Hall Sensor as the trigger. This is my first project overall dealing with electronics, and turning it into a form of decoration or art and was frustrating but inspiring to say the least in continuing with using electronics to create art and my own decorations in general. Follow along and I'll show you how to make your own 'Decorative LED Tabletop'.
Step 1: Materials List
For this proect,I used what was on hand between the class, what I had on hand, what I could recycle i.e. the wood, and everything else was bought through Amazon which I'll post links to the products:
470 Ohm resister
100 uF 16 volt capacitor
Wood (I used recycled wood varying planks and plywood)
Frosting Glass Spray Paint
Battery Pack (In my case I had a friend let me borrow his Honeycomb Charge Pack)
Rare Earth Metal Magnet
Step 2: Cutting, Soldering, and Testing Your LED Strips
First step is to cut and solder your LED lights together.
Cut a length of LED strips by the copper connections in sets of 8 until you have a total of 64 LED's to create your grid (You can vary the grid size of your strips any way you want, but I chose 64 for the impact of the LED color grid). Tape your strips onto a board to make it easier to solder your strips together, and for transit of your parts when you move them without fear of your wires breaking. Make sure that when you solder that your strips are all leading the same way by following the arrows on the strips; if your arrow is going to the right the strip below will have an arrow pointing the left, and the strip below is vice versa. Pay very close attention to this because if you don't your lines will be incorrect, and your LED's will stop at the incorrectly soldered strip.
In your roll of LED lights, they already have a connection strip that have your Power and Ground wires that turn on your LED's, but they also have an SI (Data) and Clock pin that send the code through each chip that causes the color change and speed of your lights. In the example above, I misjudged the length I would need for each wire as the wire on the outside requires a bit more length than the one on the inside, and you need a little give in order to have an evenly distributed grid for your LED's.
Cut your strips to at least 1 1/2" in length or more, and take your wire stripper and expose both ends of your wire. Twirl those ends, and pre-tin them so that it makes it easier to solder them to your LED strips. Loop them to the next strip, and use your Multimeter to check the conductivity of your Power and Ground wires between each strip to see if they make a sound. To test your SI and Clock pin soldering, you'll need to attach jumper wires to the Arduino for testing.
To test your lights, download the 'FastLED' library from GitHub to use one of their codes to test your LED lights. Pay close attention to the code to know where to stick you Clock and SI pins into the Arduino so that the code is sent through correctly. If your LED's aren't lighting up, then you may have a soldering issue. Make sure your wires are covered and attached completely to the copper ends. If the LED's only work a certain amount of strips and then stops, it could be that strip is set in the wrong direction.
Once you get all of your LED's to light up, open up a New Sketchbook to copy and paste your code into a new file, and set the 'NUM_LEDS' to 64 so that the code knows when to stop a certain number of LED's and restart at the beginning with a new function.
Step 3: Creating Your Circuit
For your jumper wires so that you can keep track of what is
what, you're going to need to use wires that match the colors of your wires attached to your LED strips. I grabbed whatever wires were on hand at the time of testing the circuit, so the yellow wires on the board are your Data/SI pins, and the white wire connecting the sensor and the Arduino should be green. But my suggestion is you attempt this, you should stick with:
When creating your circuit to connect your magnet sensor to the Arduino, you'll need a solderless Bread Board. Unfortunately, we did not have a PCB board in our schools Fab Lab that had the right circuit connection on the board, and I did not have the technical knowhow in creating a board myself from the bread board to a PCB.
When you look at your Hall Sensor, remember which pin is which when you connect your jumpers in the board. From right to left, you're going to attach your Clock, Power, and Ground pins. You have two sets of Power and Ground on your LED strip, and one set will go to one side of your board, and the others will go to the opposite side. Your power and ground from your Sensor will connect to the board connecting the sensor to the power and ground lines while your clock will attach to your Arduino. On one connection of your ground and power, attach your 100 uF 16 volt capacitor, long leg to power short leg to ground. Attach another set of Power and Ground wires as they will connect straight to your Arduino, and power your board.
You can attach your Power connections to your board just fine, but never attach your power circuit first if it's the wire connected to an actual power outlet. This will cause a short circuit and burn your board/IC chip/Sensor with it going through a current to circulate that much electricity.
For your Data/SI pin, you're going to connect it to your board in line with your Clock pin. Take your 470 Ohm resister and place it in line with your Data pin, and connect another wire to the other end of the resistor in line with the grid, and that will go to the Arduino. The resistor and capacitors will act as a buffer between these connections so as not to overheat or short circuit your board.
I used my computer for testing the circuit but you can use a battery adapter or in my case I borrowed a Honeycomb from a friend who's studying to be an Engineer. When you attach a power source, and you've attached your wires correctly into the board, your Hall Sensor should light up as seen in the picture.
Step 4: Arduino Coding
The Hall Effect Sensor registers a polarity of your Rare Earth magnet, and you can create and 'Interrupt' by setting your 'IF and ELSE' statements to register your LED cycles. For my code, I set the 'IF" statement of the Magnet not being present, it will run through the Color Wipe Cycle. When the Magnet is present, place in your 'ELSE' statement the Rainbow cycles found in your FastLED coding. Make sure when you create this code, you set the 'NUM_LEDS' to 64 so it knows how many LED's are in your grid. Also, be aware of which pins you are using when you set up your code because both the LED and Hall Sensor codes require separate pins.
Step 5: Creating Your Box
I don't have skills in cutting wood, so I had a friend help me
make it. We used recycled wood he had from his woodshop to create the board of where the LED's would be placed, the grid to lay over the top to create pinholes for the lights to shine through, and the box itself.
For the wood board the LED's stick to, you're going to cut a board:
12 3/4" x 11 1/4" was my measurements, but you can cut whatever size fits your need
To create the grid, you're going to have to create it according to the length between each LED. The LED's are an inch apart on this grid, so create your grid according to that size, and make sure you cut your grid so that is sits flush against the walls of your box. We decided to use a small staple nail gun to attached the grid together.
The strip lengths were about 14" because we decided to cut them from the side of a piece of plank wood, the thickness of each strip being 1/4" in thickness. The LED's should be seen through each pin hole in your grid, and that each opening is an inch across from each other. On the part of your grid that touched the LED's, cut small pieces of foam to block the light between each LED and glue them to your grid.
To create your box, you need to cut a plank wood that is at 3 1/2" x 3/4" at 45 degrees angles, and the inside of the plank should measure the length of your LED board. Once assembled, place your board and grid inside of your box to check it fits inside. They should sit flush against the box, but shouldn't be tight enough that you can't push/lift them back out.
On your LED board, cut into one corner of your board a hole about 3/" x 3 3/4" inch so that you can slide in your bread board, and LED wires snug against the box and board. Also, cut off where your grid covers that hole so that your Sensor can register the magnet without any obstruction.
In the box we created a ledge about 3/4" from the top of the box for it to sit on and allow the Arduino and Battery to hide underneath the box. Also, cut a section from the ledge the same length as the whole in the board so you can slide the breadboard/circuit through.
Step 6: Painting and Putting It Together
I originally wanted the box to be black, but I didn't have
any wood oil in a dark color but our family friend that put it together had some wood stain in ebony. I tried it but it didn't come out the way I wanted it to, and at how transparent it was on the wood I knew it would take several coats to get it the right amount of black I wanted. So I decided to cover it in Acrylic gesso instead; Two coats of white, and cover the wood color no problem and it'll protect it from any sudden spill of liquid.
After your box has dried, lay the grid over the board, and take a marker to mark where you're going to stick your LED's, and peel the strips and stick them onto your board. Slide your breadboard through the hole in the board, and you can bend your sensor flush against the plexiglass so that the sensor can tell where your magnet is.
For your plexiglass, trace your box on top of it, and cut it out with a push knife using a metal ruler to keep a straight edge. Clean off any finger prints with a wipe, and let dry, ten spray on the frost on one side and let dry. Do the same to the other side, and you have a frosted glass to place on top of your board.
Check to see which side of your rare earth magnet turns off the light on your sensor for that is what sends the interrupt of your sensor with the code, and glue the other side onto a token. I chose to use a see through 3-D figure I made in my Digital Multimedia class that my teacher printed out in his liquid poly resin 3-D printer.
Step 7: Final Step
Place your board, then your grid, and lay your 'glass' into your box and there you have your own 'Decorative LED Tabletop'.
Check out my Blogspot to see how the project works in motion.
Thank you for checking out my project, and let me know if you ever attempt it in the comments section and have a wonderful day!