Jameco Electronics 8x8x8 LED Cube User manual

8x8x8 LED Cube
PART NO. 2168940
This LED Cube will light up any party. Your friends will be mesmerized by its hypnotic effect as lights dazzle and dance in brilliant
patterns. It utilizes code based off of Instructables designer, CHR, and uses an Arduino UNO to power the cube and act as a
programmer. This cube gives of a warm glow that is pleasant to the eye to entertain any person of any age. Though it might quite a
commitment to build, the effort will be worth the wait. Surprise your friends and family with this incredible art piece, as it will be sure to
turn heads. Don't skip this wonderful project because it offers invaluable opportunities for electronic construction and Arduino coding.
I'll just leave it up to this video to convince you that this will be the next project you will be building.
http://www.youtube.com/watch?feature=player_embedded&v=6mXM-oGggrM
Time Required: Several Days depending on experience
Experience Level: Advanced
Required tools and parts:
Soldering Iron
Solder
Helping Hands
Wire Cutters/Strippers
Needle Nose Pliers
Vice
Aluminum Foil
Peg Board or piece of wood
Drill
Bill of Materials:
Qty Jameco SKU Component Name
100 690620 100 ohm Resistors
1 206587 Prototyping Board
3 333973 Status Red LEDs
8 38608 20 Pin Chip Sockets
1 37373 16 Pin Chip Socket
8 46084 SN74HC574N Chip
1 45330 74HC138N Chip
9 153702 8 Pin Male Header
3 70755 8 Pin Female Header
16 178511 2222A Transistor
1 330722 1000uF Capacitor
1 93761 100uF Capacitor
1 29891 10uF Capacitor
1 690718 240 ohm Resistor
1 643831 16 Strand Ribbon Cable
9 525325 Ribbon Cable Header
1 2151486 Arduino UNO
2 139231 1" Standoffs
4 139222 3/4" Standoffs

4 40970 Screws, 4-40x3/8
4 40943 Nuts, 4-40
1 222010 USB Cable
1 2138636 AC Adapter
550 2168421 3mm Round Diffused Blue LED 5K MCD Bulb Light
10 25523 .1uF Capacitor
1 2153705 25-Foot Hook-up Wire Bundle
Step 1 - Test the LEDs
You will need 512 properly working LEDs in the lattice. They will need to be stable and bright. This step will show you how to separate
the faulty ones from the usable ones.
Lots of times there are broken LEDs, especially when they come in large packages. The damage may be noticeable but sometimes it
is not. Start by bending the shorter leg (the cathode) at a 90 degree angle. Hook it up to a power supply and run 3V across it. You can
do this with 2 AA batteries in series, but I had a power supply with alligator clips. Either way, just make sure the LEDs are working
before you begin to solder.
Step 2 - Build the Rig
Create an 8x8x8 template so you can create the layers. You will need a peg board and you will need to drill holes into the peg board
to space the LEDs 1/2" apart. I put foil over my rig to hold the LEDs in place so that they wouldn't move while I solder, otherwise they
would jiggle to much. Use the LEDs to punch holes into the foil.
Step 3 - Starting the Layer
The picture should show you how to do it, but basically have all of the LEDs in the row facing the same way. Begin with the corner
first. The corner row should be 90 degrees facing the other way. You should also align each LED so it is just barely touching the next

one. When you solder, don't hold the iron more than 2 seconds on the LED, otherwise it can be damaged. Apply minimal solder
between each LED. I would NOT recommend to cut any wires until you have a working structure.
Step 4 - Solder in Rows
Go row by row, in the same way as before. Make sure to apply minimal heat, and place the legs just close enough to each other, but
not too close.
Step 5 - Add Reinforcements
You must strengthen each layer to make them stable and durable. This is so the layer doesn't come apart when you pull it off the rig.
Cut a piece of wire longer than the length of your layer and strip off the insulation. Place the long, stripped wire into a vice and pull
hard to straighten it. You can do this with another set of pliers as well. You should feel the wire get longer and straighter as you pull.
Once it is straight enough, place it on the opposite end of the layer and solder it on the cathodes to stabilize the rear end. Do this
once more for the middle section, as now it is the weakest part of the layer. I used clips to hold the reinforcement bar in place while I
soldered. These bars should strengthen the rear and middle of the cube so it won't break.

Step 6 - 8 Identical Layers
Repeat the last three steps another seven times to complete your layers. This will take patience and time.
Step 7 - Let's Get Vertical
Now with eight different layers, we will build up!
I used triangular folds of paper to hold each layer above the other when I soldered. Make sure to place the first layer in the rig and
start from there. I would recommend to bend the leads slightly so you can have each layer directly above the other, otherwise it can
come out slightly crooked. Apply minimal heat and solder, and be careful when going into the cube with the iron. Read Step 10 before
you begin to solder.

Step 8 - Looks Like Raindrops
It should be looking good up to here.
Step 9 - Ground Lines
The final step in lattice construction.
These eight extra wires will drop down from each row to connect them to the board. So far, we have column connections but with
these lines we will be able to control individual LEDs by separating the columns and rows apart.
Do this by stripping wire as before and creating hooks at the end to secure each to its layer. Use solder to hold in place only at the
row each line is designated for. Make sure each line only touches its layer and no other. They should extend the same length as the
bottom-most legs.

Step 10 - Finishing the Lattice
It should look something like this, although mine came out slightly rectangular because I spaced the layers out more than half an inch.
Ultimately, this won't affect animations but it adds a personal effect to it.
Step 11 - Start the Controller
Now let's start on the controller. Start by placing the chip sockets next to each other but to leave enough room for resistors and
headers. I would advise to economize space but to leave yourself enough room to solder and place wires.
Allocate a common GND and VCC line that will connect to each socket. I used small 0.1uF capacitors that are placed in between
each socket for the VCC and GND line. The black wires are for the common GND line. VCC goes to pin 20 and GND goes to pin 10.
Refer to the schematic in Step 12 for the rest of the steps.

Step 12 - Circuit Schematic
Step 13 - Solder Trails
Use solder trails to minimize wiring. I used them to bus a VCC line to each chip socket.
Refer to this video if you don't know how:
http://www.youtube.com/watch?feature=player_embedded&v=kROaQZOYNIw

Step 14 - Power Terminal
This is the power portion of the controller board. It consists of a couple of capacitors and a status LED. Follow the top most diagrams
in the schematic. You may or you may not want to include a power switch... I didn't.
Step 15 - Data Lines
Connect the chip sockets to each other. You will need to connect each identical pin to the other in one bus. This is what that blue line
on the schematic means. So connect pin 1 to all the other pin 1's and do this for the rest of pins 2-8. Think of it as daisy chaining the
pins to each other.

Step 16 - Resistors and Headers
Use those 100 ohm resistors in between pins 12-19 and the 8 pin male header for each chip. These resistors should be enough,
assuming you're powering 5V from the Arduino. The male headers are used to connect to each of the eight rows of the lattice.
Step 17 - Address Selector
The address selector chip will control the clock cycles to each chip. Start by soldering the GND and VCC connections. If you use the
solder trace method to run GND/VCC lines, you want to do this before you solder any other wires in place. A 100nF ceramic filtering
capacitor is placed close to the VCC and GND pins of the 74HC138.
Then connect the address lines and the eight clock lines.
If you look carefully at the connector, you can see two pins that are not used. These will be used for a button and debug LED later.

Step 18 - Transistor Schematic
Use this schematic for the following step
Step 19 - Transistor Array
The transistor array is responsible for switching on and off GND for each layer in the LED cube.
For each layer, use two PN2222As in parallel. The collectors are connected together to GND. The emitters need to be connected
together in pairs, then connected to a male header. Introduce the pull-up resistors to reduce ghosting. The base of each transistor is
connected to it's own resistor, and they are paired up to be connected to an output pin on the Arduino. Connection to the Arduino will
come shortly.
We soldered in all the transistors and turned the thing on again, and it worked, perfectly!
1) Start by placing all 16 transistors on the PCB and soldering each of their pins.
2) Run a solder trace between the the emitters of all 16 transistors. Connect this solder trace to GND.
3) Solder in a resistor for each transistor, the solder the resistors together in pairs of two.
4) Run wire from each of the eight resistor pairs to a female header. This is where the Arduino will connect.
5) Solder together the collectors of the transistors in pairs of two and run solder trace or wire from the collector pairs to an 8 pin male
header. Place 100 ohm resistors between the header and VCC.