Green Digit Technologies

Creative Commons-Licentie

LED Cube

inleiding

A ledcube is a cube constructed out of leds, and ofcourse the components needed to control the leds. I chose to make a cube of 3*3*3, 3 leds in every direction.
To drive the cube you need 1 pin of the microcontroller for each column and 1 pin for each plane. This means I need 9 pins for the column driving and 3 pins for the plane driving, making a total of 12 digital IO pins. Every microcontroller with 12 IO pins will suffice.

Video



Requirements

  • PCB, etst or veroboard
  • 27 LEDs, preferably diffused LEDs
  • 9 2k2Ω resistors
  • 9 33Ω resistors (or 3 100&Omega resistors in parallel like I did)
  • 6 10kΩ resistors
  • 18 1n4148 diodes
  • 9 BC557 (or equivalent)
  • 3 BC547 (or equivalent)
  • Some wire
  • Arduino or other microcontroller

       Every Ardiuno can be used.
       Using a atmega328 as standalone would work without a problem.


Schematic

There are many nice tutorials on how to make a ledcube. Google is your friend. Tutorial
There are many more tutorials on the Instructables website.

The control circuit consists out of 2 parts: the microcontroller, and the transistor driving.
The resistor R1 limits the current. The calculation of the resistance value is therefore important. The voltage across the diodes is between 1.2V and 1.4V. Knowing that we have a voltage drop around 0.7V (according to the datasheet) we have a voltage drop between 0.5 and 0.7V. This makes it possible to calculate the value we need for the resistor. I chose a 33Ω resistor, making the maximum current around 16mA.

The code

Ofcourse this cube is nice, but without the software it just some leds that doesn't light up.
Write some nice software along with it ;) you'll like it better that way.
Writing it yourself is much more fun then copying it from me so give it a go :D