Prop Triggers
A trigger detects a visitor and fires an effect — a light, a sound, a moving prop. The trigger is what makes a haunt interactive rather than a static display. Different trigger types have different strengths depending on where and how you want to detect visitors.
PIR Motion Sensors
Passive infrared sensors detect body heat in motion. They're the most common trigger in home haunts because they're cheap ($2-5), easy to wire, and work reliably outdoors. Available as raw modules (for Arduino wiring) or built into commercial prop controllers.
Limitations: PIR sensors detect motion across their field, not at a precise point. They can false-trigger from animals, wind-blown objects, or heat sources. Adjust sensitivity down and narrow the detection cone with tape over parts of the lens to reduce false triggers.
Pressure Mats
A mat placed under a floor covering or rug that closes a circuit when stepped on. Gives precise positioning — you know exactly where the visitor is standing when the trigger fires. Commercial haunt mats are available, or DIY from two sheets of aluminum foil separated by foam with holes cut in it (stepping on it compresses the foam and the foil sheets make contact).
IR Break Beams
An infrared LED shines across the path to a receiver on the other side. When someone walks through and breaks the beam, the trigger fires. Very precise positioning — the effect fires the instant someone crosses a specific line. Available as matched sender/receiver pairs from electronics suppliers or Amazon.
Trip Wires (Electronic)
A thin wire or string across the path connected to a microswitch. When pulled, the switch closes and fires the trigger. Simple and reliable but needs to be set up where visitors won't be harmed by it. Use breakaway string that snaps easily.
Manual Triggers
Sometimes the best trigger is a person watching and pressing a button at exactly the right moment. A live operator can time scares perfectly and choose not to fire on small children. This is especially useful for pneumatic pop-ups and loud startle sounds where timing and target selection matter.
Connecting Triggers to Effects
Most triggers output a simple on/off signal. Connect this to:
- A relay module to switch power to lights, motors, or fog machines
- An Arduino for programmable sequences
- A timer/controller board for timed activation cycles
- A solenoid valve for pneumatic props