The Light-up Sign

1. At the top of the page, type your name and click Download my 3D parts.
2. Open the _body.stl files in your printer's software. Print them in coloured PLA, lying flat on their back, no supports.
3. Print the _front.stl files in white PLA. They're thin, so light shines through.
4. Suggested settings: 0.2 mm layers, 3 outlines ("perimeters"), 15 % infill.

Tip

Print just one letter first as a test. If all goes well, start the others. And write each letter's number inside it in pencil!

1. Paint the board if you like (let it dry well).
2. Lay your letters on it, nicely lined up on a pencil line.
3. For each letter, mark in pencil where its wire hole is.
4. With a grown-up, drill a 14 mm hole on each mark.
5. Screw two battens on the back of the board: they leave room for the wires and the Arduino.

With a grown-up

The drill is always used with a grown-up. You make the marks and hold the board.

Here's the layout plan for your name. The black dot is the wire hole, the green circles are the pixels, in the order of the string.

1. Find the end of the string where the little arrows start from: that's the input. It goes to the Arduino.
2. Pass the string from the back of the board into the first letter, through its hole.
3. Glue each pixel lying down in its spot with a drop of hot glue, its head facing the middle of the letter.
4. Come back out through the same hole and carry on to the next letter.

A pixel too many?

If the letters are far apart, a pixel may end up hidden behind the board. That's fine! You'll find it again in step 5.

Everything plugs into the breadboard. The two long lines along the edge are the power roads: + (5V) and − (GND).

Golden rule

We wire everything with the power unplugged. The capacitor has a direction: the stripe on its side always goes to −. Ask a grown-up to check before plugging back in.

Wire colours

Colours change from one string to another. Read what's written on the first pixel's little circuit instead: 5V, DIN, GND.

1. In Arduino IDE, open Tools → Manage Libraries, search for FastLED and click Install.
2. Choose the Arduino Nano board, plug in the 5 V power supply, then the USB cable.
3. Upload this program: it lights the pixels one by one and writes their number in the Serial Monitor.

4. For each letter, write down the number of the first pixel that lights up inside it and how many pixels it holds.
5. Fix the table if needed: the big program updates itself.

This program was written especially for your name. The button changes the animation, and the green comments explain everything.

Switching off by itself?

Your room might be noisy. Raise CLAP_THRESHOLD (try 450, then 550) so only real claps count. If it doesn't hear your claps, lower it.

Red and green swapped?

If your rainbow has strange colours, replace RGB with GRB in the addLeds line. Every string has its own habits!

1. Check that every letter lights up before you close them.
2. Put a thin line of glue on top of the walls and lay the white front on it.
3. Glue each letter onto the board, its hole lined up with the drilled hole.
4. Stick the Arduino and the breadboard on the back of the board with double-sided tape.
5. Screw in two hooks and hang your sign on the wall!

Tip

Keep the button reachable at the side of the board so you can change the animation without taking everything down.