3x3x3 LED Cube

Hello guys, I would like to show you, how to create 3x3x3 LED Cube.

It is a simple way to make a great decoration for your room. This was my first PCB project. It was a great experience, I had a great time and I have learned a lot of things about PCB design and production.

Model:

1x Binary switch
1x DC female jack 5,5mm/2,1mm
27x 5mm LED

PCB:

Arduino:

1x Atmega328P-AU

1x Quartz crystals 16MH

2x capacitor 22p 0805

1x capacitor 100n 0805

1x chipLED red 0604

1x resistor 1k 1206

1x male pinheader 2x1

RESET:

1x button

1x resistor 10k 1206

ICSP:

1x male pinheader 6x1

1x chipLED red 0604

1x resistor 1k 1206

Rows:

3x transistor BC547

3x resistor 1k 1206

1x male pinheader 3x1

Columns:

1x male pinheader 9x1

Each layer of the cube consists of 9 LEDs.

We can not connect both sides of the LED to Arduino pins. We are going to do that by bending and then soldering all 9 LEDs cathode legs. It will create the frame of the cube and all of the anodes will go straight down to the base. We will repeat this 3 times, so we will create 3 floors of the cube.

I designed the base for the PCB and LEDs in Autodesk Inventor 2020
I made holes in the main part of the base, for the DC jack connector and binary switch.
In the bottom part, I made cut out for the glass pane, so I can see my PCB inside the base.
The connection between the bottom and the main part is by 4x M3 screws, which I covered with self-adhesive anti-slip pads.

I designed my first PCB in Autodesk Eagle.
As I said before we can not connect both legs of the LED to the Arduino pins. Each column consists of 3 floors (3 anode legs of the LEDs)
All of the columns are connected to Arduino pins.
Each floor is connected to the emitter of the NPN transistor. The collector of the transistor goes to the ground. This transistor will be controlled by Arduino pins, via the base of the transistor.
This will allow us to control all of the floors by Arduino.

When we soldered all the floors together, we only have to do one step before we can put it into the base.
We have to solder 3 cables, each for one of the floors. Now we can insert LEDs to the base.
After that, we have to band all of the LEDs legs, so the construction won't fall apart
.Now we solder Arduino cables to the bent legs, which we will connect along with the floor cables to the PCB.
After that, we connect the binary switch and the DC Jack in series.
Finally, we connect it to the Arduino as supply.

Before we can program our DIY Arduino, we have to burn the bootloader with another Arduino through the ICSP.
After that, we use the second Arduino as a programmer of our DIY Arduino.
The program consists of several modes of blinking LEDs.

After downloading the program to our DIY Arduino and screwing both parts together, we can connect 5V adapter to our DC Jack and turn on the LED cube.
Thank you for reading my instructable.
I hope you have enjoyed it and find it helpful.