LEGO + Arduino = Brickduino (1. the LED)

I know LEGO has the Mindstorms-set that probably is great, but wouldn’t it be even better (and cheaper) to hack your regular bricks into your own micro controller controlled LEGO? Well I think so!
I had this idea for a long time, but to many other projects stood in the way until Tristram posted this instructable: DIY-LEGO

We tried to work together on this project, but it seemed impossible to synchronize our agenda’s and get together so we both run our own projects. First I took the same route Tristran took and even build myself a MYDIYCNC to cut the bricks, but finally I decided to take an other approach.

A nice first step in this project will be a simple LED in a brick.
(Tristram also did a LEGO-LED but with his own approach)

My goals for the LEGO-LED:

• It must be 5V so is can be easily controlled by an Arduino micro controller
• It must fit in a 2×2 brick and be flush within the brick
• There must be come logic in the positive and negative poles
• There must be a easy (LEGO-like) system to connect cables
• The design must be useful for different modules in the future, like sensors and switches. (so there must be a possibility for three poles: 5V, GND and signal)
• It must be repeatable
• It must be cheap (not counting the CNC I build for it)
• It definitely must look cool

Step 1: You will need:

[box color=”#985D00″ bg=”#FFF8CB” font=”verdana” fontsize=”14 ” radius=”20 ” border=”#985D12″ float=”right” head=”Major Components in Project” headbg=”#FFEB70″ headcolor=”#985D00″]

For starters you will need a bunch of LEGO-bricks to destroy. I couldn’t destroy my LEGO, so I bought it specially for it in “Pick a Brick” on the LEGO site.

LEGO:

• 2×1 black bricks
• 2×2 black bricks
• 2×1 red plates
• 2×2 red plates

Other stuff:

• M2.5 x 5 mm bolts
• M2.5 nuts
• 0.5 mm copper plate
• small electrical wires
• 5mm LED
• The fitting resistor to light the LED on 5V
• (if you want) 6 mm plastic, aluminum of wood and 4 mm aluminum to make rigs

Tools and stuff:

• Needle nose pliers
• Wire cutter
• Small screwdriver
• Phillips head screwdriver
• Drillpress (it might also be doable with a hand drill)
• Drills: 2.5 mm, 4,5 mm, 5 mm, 5.5 mm an old 8 mm wooddrill
• A CNC is helpful, but small files might also work
• Soldering tools
• Razor blade
• Super glue
• Grinding wheel or power sander[/box]

Step 2: 1) The cables

Normally I wouldn’t start with the cables, but my bricks for the LED-module aren’t delivered yet, so the cables it will be.

The cable will be a 1×2 black brick with one of the studs made into a connector and a 1×2 red plate on the bottom with the little round stud in the middle replaced by a connector.

The hole in the Bottom plate

To make the connector, we need a 3mm x 4 mm hole though the 1×2 plate. I use my CNC for that. (you can also use a drill and file). To make it easier to repeat, I first made a jig to hold the brick out off 6 mm thick HDPE plastic. The G-Code to make the jig is included in this instructable. I used a 1.4 mm bit in the CNC.
As you can see on the pictures, the LEGO fits snugly in the jig. When I zero-out the CNC on the little hole I made in the jig, the bricks will be cut perfectly every time. (G-code included. You might need to change the .txt extension in .ngc)

 

For more detail: LEGO + Arduino = Brickduino (1. the LED)