Color-Cycling Light

A light that steps through a list of colors, one each second, for a party floor, a shop sign or a stage. A switch turns it on and off.

Contents

• You need
• Code
• Wire it
• Check it in game
• Change it
• How it works

You need

• a Switch
• a brick with a Point Light

switch Enabled -> chip running
chip lamp -> light Color
chip lit -> light Enabled

Code

const STEP_SECONDS = 1.0 // how long each color stays on
const COLORS = [
  Color(1.0, 0.0, 0.0),
  Color(1.0, 0.5, 0.0),
  Color(1.0, 1.0, 0.0),
  Color(0.0, 1.0, 0.0),
  Color(0.0, 0.3, 1.0),
  Color(0.6, 0.0, 1.0),
]

@left in running: bool
var shown: color = Color(1.0, 0.0, 0.0)
@right out lamp = shown.Value
@right out lit = running

on Clock(interval = STEP_SECONDS, enabled = running) {
  shown = COLORS[Cycle(COLORS.length())]
}

Wire it

1. Compile the chip and paste it in-game. Place the Switch and the Point Light.
2. Open the Point Light’s settings and turn off Use Brick Color. While it is on, the light takes the brick’s color and ignores the wire.
3. Wire the Switch’s Enabled to running.
4. Wire lamp to the Point Light’s Color, and lit to its Enabled.

Check it in game

• Flip the switch on: the light comes on and changes color once a second, in the list’s order: red, orange, yellow, green, blue, purple.
• After purple it goes back to red and carries on.
• Flip the switch off: the light goes out. Flip it on again: it carries on from the color it stopped at.

Change it

• Change the speed: const STEP_SECONDS = 0.25 for a disco.
• Use your own colors: add, remove or reorder the Color(red, green, blue) lines. Each channel runs from 0.0 to 1.0. The cycle follows the length of the list, so nothing else needs to change.
• Fade from one color to the next instead of jumping: @right out lamp: color = Tween(shown.Value, 0.5). A Tween moves toward its target over 0.5 seconds (Game Enums).
• Keep the light on with the switch off, frozen on one color: wire the Point Light’s Enabled from a Switch of its own instead of lit.

How it works

The Clock runs its handler every STEP_SECONDS while running is on (Reacting to the Game). Cycle(n) is the game’s Counter gate: each pulse moves it on by one, from 0 up to n - 1 and then back to 0. Its number picks a color from COLORS, a const array: a fixed list that never changes while the game runs, read by index like any array (Lists). The handler stores the color in shown, which drives the light’s Color (Vectors and Colors).