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There are other Instructables about building LED cubes, this one is different for several reasons:
1. It's built with a low number of off-the-shelf components and hooks up directly to the Arduino.
2. A clear, easy to reproduce circuit diagram is provided with plenty of photos.
3. A unique approach is used for the software which makes programming the cube easier and more expressive.
Parts needed:
- 1 Perfboard
- 3 NPN Transistors (2N2222, 2N3904, BC547, etc.)
- 12 Resistors (~220 ohms and ~22k ohms)
- 13 Headers (male or female)
- 27 LEDs
- Jumper wires
1. It's built with a low number of off-the-shelf components and hooks up directly to the Arduino.
2. A clear, easy to reproduce circuit diagram is provided with plenty of photos.
3. A unique approach is used for the software which makes programming the cube easier and more expressive.
Parts needed:
- 1 Perfboard
- 3 NPN Transistors (2N2222, 2N3904, BC547, etc.)
- 12 Resistors (~220 ohms and ~22k ohms)
- 13 Headers (male or female)
- 27 LEDs
- Jumper wires
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Signing UpStep 1Prepare the LEDs
This step largely follows the LED Cube 4x4x4 but we'll be building a 3x3x3 cube instead. A cube of this size is about as big as it gets without introducing additional circuitry and complexity. We'll need a total of 27 LEDs that will be grouped into three sets of nine.
Each set of nine LEDs will share a common connection amongst their cathodes (negative leads). I'll refer to each of these sets as a "level". Each of the nine LEDs on a level is connected to the corresponding LED on the other two levels through their anodes (positive leads). These will be referred to as "columns". If that didn't make sense it will become self explanatory as we build the cube.
To start we'll use a drill to create a jig out of a small piece of scrap wood. The jig will hold the LEDs in place while we solder them. I decided to space the holes around 5/8 of an inch apart (~15 mm) but the exact distance isn't critical. The hole should have a tight fit around the LED since we don't want them to move around while soldering.
Once the jig is done we're going to bend the cathode of each LED in a 90 degree angle. The cathode is identifiable in three ways: 1) It's the shorter leg, 2) It's on the flat side of a round LED, 3) it's connected to the larger piece inside the LED. Make sure you bend the cathode in the same direction for all of the LEDs.
Now we're ready to begin soldering.
Each set of nine LEDs will share a common connection amongst their cathodes (negative leads). I'll refer to each of these sets as a "level". Each of the nine LEDs on a level is connected to the corresponding LED on the other two levels through their anodes (positive leads). These will be referred to as "columns". If that didn't make sense it will become self explanatory as we build the cube.
To start we'll use a drill to create a jig out of a small piece of scrap wood. The jig will hold the LEDs in place while we solder them. I decided to space the holes around 5/8 of an inch apart (~15 mm) but the exact distance isn't critical. The hole should have a tight fit around the LED since we don't want them to move around while soldering.
Once the jig is done we're going to bend the cathode of each LED in a 90 degree angle. The cathode is identifiable in three ways: 1) It's the shorter leg, 2) It's on the flat side of a round LED, 3) it's connected to the larger piece inside the LED. Make sure you bend the cathode in the same direction for all of the LEDs.
Now we're ready to begin soldering.
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1) As suggested by the instructor, if I were to do another one of these, I would wire up the LEDs so that the cathodes are on the outside (i.e., the gnd connections that all LEDs on a single level share) and the anodes were on the inside (i.e., the + connection shared by all LEDs on a single column). I did it the opposite way, and i had to bend a lot of the leads on the columns over the LEDs below. Also, I had two rows of blue and one row of red because that's what I had on hand.
2) Definitely be careful about all of the overlapping wires connecting the resistors to the cube's columns. I didn't have electrical tape and used duct tape, which I wouldn't recommend. I'm having some problems with one particular column (#3) not lighting up, which I suspect has something to do with having several different wires overlapping it.
3) I did not have the fancy pin connectors shown in the picture, so what I did was take a bunch of rubber coated leads I had from a starter pack and pulled off one of the metal tips from the rubber gaskets on the end. I then plugged those (now female) sides of the leads onto the pins sticking up from the perf board.
4) This took me several hours to build and solder, but I was extremely happy with the sucker powering up and dancing on the first try. The sample library compiled and uploaded without error on an Arduino Uno r3 and Arduino 1.0.
Booya
Secondly, how can I expand this to be 4x4, 8x8, etc. Is your library scalable - what modifications would need to be made? I hope you answer, I loved this project...
I tried to keep a scalable library in mind while coding but its still mainly geared towards a 3x3x3. If you're comfortable making modifications I can take a closer look to give you an idea of what it might take. You'll still need either more pins or some type of shift register or driver to power more LEDs.
My power source is the arduino at 5v - I'm using the Modern Device board. Should I be contemplating an external power supply?
I am changing gears and will use shift registers... I want to build an 8x8x8 cube... I now have 3x3x3 and 4x4x4 cubes working fine using your library... Which is great.
I think it would be great to have your library handle the 8x8x8.
I just finished making an acrylic template that will allow me to build a more precise cube. The wood base lent itself to errors... I used a laser cutter for the acrylic...
Also, I was not sure if I needed to change the library or not. There were some items in the example code I though to change but I am not sure. I have java experience but I am new to arduino, so understanding code is easy but understanding the arduino is harder.
Would you be willing to send me the source for your 4x4x4 so I have something to work off of? Thanks.
Cool that you're able to use the lib with a 4x. How many mods did you have to make? Send me the code when you have a chance.
i use the latest arduino software. its the same as andray.
What version do you use Jwgillon?
See this http://arduino.cc/forum/index.php?topic=81078.0 for more information.
I've build this cube Will this code work on ARduino Uno. Getting a Bunch of Compile errors
Thanks for sharing
Danie
sorry i dont want to wast your time, just trying to figure things out.
I used female headers so I could use the jumper wire I had.
Heres a pic
I would kill to get some more code, effects for my cube but I just can't get my head to figure out how to do this...
anyway, thanks
Eric
Thanks
http://img.instructables.com/files/deriv/F01/I0OW/GUOAEGJA/F01I0OWGUOAEGJA.SQUARE.jpg
that was a try...
Thanks again for the great instructions.
yes the value would be higher then what you are using i.e 1 watt but i think that may work but i could be wrong anyway i have nearly finished my own so i will try this with a 50 Ohm POT, anyway thanks for your help.