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8x8x8 LED Cube

My last HackerBox, #0030: Lightforms, came with an 8x8x8 LED cube kit. I started building it in May, when I assembled the PCB and made a jig for assembling the grids.

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8×8 jig

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I got busy over the summer and the thought of soldering 512 LEDs didn’t excite me. After catching up on all of my other kits, it was finally time to dive back in.

I thought I took some video of assembling the board, but I must have deleted it. So I didn’t bother with any video while assembling the grids either. The repetition would have been quite boring. I thought I’d do a gallery with captions for a change.

Assembled circuit board.
Simple circuit used to test the LEDs and compare brightness.
3D printed jigs. I ended up not using the grid one because my plywood jig fit much better.
My friend Kevin printed this awesome jig, which made bending the legs much easier.
Over 500 LEDs before and after being bent. It took over 90 minutes to test and bend them all.
One 8×8 grid all soldered in the jig.
All 8 grids completed without burning a single LED. I can’t believe I didn’t swap the leads when I bent them all.
Complete! Only had to rewire the cathode connections to the board because the instructions were actually wrong.
While assembling the 8×8 grids I settled on a pretty good system, so I recorded myself doing a couple of rows to show my method.

This is definitely my longest electronics kit in terms of hours spent and it had so much repetition. Pretty cool result. Here is someone’s demo showing what can be done with the cube.

I’ll need to upgrade the firmware so I can program the board with my own animations.

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12 Volt Light Bulb Tester

I wired a 9V in series with two AA batteries (1.5V each) to test out the truck‘s dash panel bulbs.

Turns out the bulb holder I tested first was faulty and 9V would have been enough. In fact, three of the nine bulb holders were corroded and unable to provide juice to the light bulbs. That explains why it was so hard to see the gauges at night!

To get by until new parts arrive, I was able to finesse some small pieces of wire in between the bulbs and the holders to get an electrical connection.

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Unboxing HackerBox #0030: Lightforms

Quick unboxing video for the latest HackerBox.

Official box contents from the Instructable:

  • HackerBoxes #0030 Collectable Reference Card
  • NodeMCU V3 Module with ESP8266 and 32M Flash
  • Reel of 60 WS2812B RGB LEDs 2 meters
  • 8x8x8 LED Kit with 8051-Based MCU and 512 LEDs
    • PCB
    • Reusable Plastic Parts Box
    • Two 4.7 KOhm Resistors
    • Eight 470 Ohm Resistors
    • 10 KOhm Eight Resistor Array
    • STC12C5A60S2
    • 40-Pin DIP Socket
    • Eight 74HC573 Octal Latches
    • Eight 20-Pin DIP Sockets
    • ULN2803 Transistor Array
    • 18-Pin DIP Socket
    • Two 10uF 25V Electrolytic Capacitors
    • Two 22pF Ceramics Capacitors
    • 12MHz Crystal Oscillator
    • Barrel Power Socket
    • 4-Pin Serial Header
    • Power Switch
    • Cable with USB to 5V Barrel
    • Red Hookup Wire
    • 550 LEDs
  • USB Serial Module with CH340G and Jumper Wires
  • Stranded Hookup Wire 3 meters, 22 gauge
  • Exclusive HackerBoxes Decal
  • Exclusive Dark Side LED Decal

It’s disappointing that HackerBoxes resold us a popular kit that you can get for $15-20. I’ve seen these LED cubes many times online and while they do look awesome, I never bought one because I didn’t think I’d have the patience to put one together. I guess I’ll get the chance now.

I’ll probably try to do a time-lapse of this assembly, which is going to take a long time.

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Fixing a Simple Button & LED Circuit

I found an old Christmas ornament which was supposed to light up by pressing a button. Before trashing the ornament, I tore out the circuit. While I was taking it apart and figuring out why it didn’t work, I turned on the camera and talked to myself. Probably boring for most people, but it might be interesting to see what I was thinking through the process. If you’re new to electronics (like me) it may even teach you a few things.

This is completely raw and unedited footage. Sorry about the noise in the background. I was using an electric heater because my boiler wasn’t heating up the house properly.

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Test LEDs with a Coin Cell Battery

The battery (CR2450) in my garage door sensor was getting low, so I replaced it. I’ll keep the old one in my electronics kit for LED testing, as shown in this video. Touch the longer leg (anode) of the LED to + and the shorter leg (cathode) to –. Usually + is the top of the battery where the words are. Don’t worry, you won’t hurt the LED if you connect it the wrong way.