Drawbridge

A bridge on a hinge that a button raises and lowers. A warning light shines while it moves, and presses during the move are ignored.

Contents

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

You need

• a Bearing (Servo) brick, the hinge (its component is called Servo)
• the bridge deck: a piece built on its own and attached to the servo
• a Button
• optional: a brick with a Point Light, the warning light

button Held -> chip pressed
chip angle -> mover "Target Angle"
chip warning -> light Enabled

Code

const DOWN_ANGLE = 0.0 // the servo's angle with the bridge down
const UP_ANGLE = 90.0 // the servo's angle with the bridge up
const MOVE_SECONDS = 4.0 // how long the warning light stays on after a press

@left in pressed: exec
var raised: bool = false
var moving: bool = false
@right out angle: float = if raised.Value then UP_ANGLE else DOWN_ANGLE
@right out warning = moving.Value

on pressed {
  if !moving {
    raised = !raised
    moving = true
    await Sleep(_, delay = MOVE_SECONDS)
    moving = false
  }
}

Wire it

1. Compile the chip and paste it in-game. Place the Bearing (Servo) at the end of the gap, where the bridge should pivot. Build the deck and attach it to the servo. The servo’s description in the game says how (with the placer or the manipulator).
2. Wire the Button’s Held to pressed.
3. Wire angle to the Servo’s Target Angle.
4. Optional: wire warning to the Point Light’s Enabled.

Check it in game

• Before any press, the bridge stays as you built it: flat across the gap.
• Press the button: the warning light comes on and the bridge swings up.
• Press again while the light is on: nothing happens.
• After the light goes off, press again: the bridge comes back down.
• If the bridge swings down into the gap instead of up, set UP_ANGLE = -90.0, or turn on the servo’s Reversed setting.
• If the bridge does not move at all, check that the servo’s Enabled setting is on.

Change it

• Raise it only partway: const UP_ANGLE = 45.0.
• Match the light to the bridge: time how long the bridge takes to move, and set MOVE_SECONDS to that.
• Run it from a Switch instead: wire the Switch’s Enabled to a new @left in up: bool pin and write @right out angle: float = if up then UP_ANGLE else DOWN_ANGLE. The bridge then follows the switch, and the handler and both variables can go.
• Make it a gate or a barrier arm: the same chip turns any servo between two angles.

How it works

raised remembers which way the bridge should be (Remembering Values). angle picks one of the two angles from it with if ... then ... else (Choosing a Value), and the servo turns the deck until it reaches that angle. The handler flips raised, then holds moving on for MOVE_SECONDS with await Sleep (Pure and Exec). While moving is on, the if !moving check skips the press, and warning lights the lamp. The chip never measures the bridge: the light’s time is a guess you set.