Inductive Sensors for Escape Room puzzles

"Magical" interactions in escape rooms use a variety of electronic sensors to detect and trigger effects based on the players' actions. Many escape room puzzles use magnetic or RFID sensors to determine if, or what, object has been placed in a particular spot. But it's not always possible to attach a magnet or RFID tag to every object - and certainly not to conceal it.
In this video, I'll present an alternative sensor - an inductive sensor that detects the presence of any nearby metallic object. I'll show you the wiring required to use one or more of these sensors, so that players are required to place a number of metal artefacts in particular spots in order to activate a relay and unlock a maglock.
This tutorial requires only a handful of easily-sourced electronic components and, unusually for me, no Arduino or ESP32!
00:00:00 - 00:03:12 Introduction and demonstration
00:03:13 - 00:05:22 How inductive sensors work
00:05:23 - 00:07:59 Detection range test
00:08:00 - 00:14:37 Wiring for PNP and NPN sensors
00:14:38 - 00:16:03 Wrapup
If you enjoyed this video or found it helpful, please like and subscribe to this channel. And, if you'd like to download the resources used in all the escape room projects shown on this channel (and support me to continue making more tutorials in the future!), please check out my Patreon at / playfultech
#escaperoom #tech #puzzle

[@javcis31]

Fantastic video! Coding intimates me to no end, so I appreciate you exploring a strictly-hardware approach to puzzle designing. I'm always surprised with how much you can do with fairly simple circuits!

[@ZWBenedict]

Recently discovered your videos and binged watched a bunch. Was happy to see your still uploading videos. Thanks for great content.

[@PlayfulTechnology]

Awh, thanks! Glad you find them useful. I try to upload at least one video each month - I know there are channels who do much more frequent videos than that, but they typically have an entire production team behind them, and I'm just me :)

[@gercovanstraten63]

Wonderful video and very well explained.. again 😉 We'll be trying these sensors in a candle prop puzzle to put out the candles with a metal candle douter. Thanks for another great idea!

[@shivanibhardwaj9988]

Hey I need your help for the video you made on AR app. Please respond

[@rjai88]

You mention them being wired into a relay but there isn't one in your wiring diagram. How would this work? And could you use a magnetic release catch rather than a maglock?

[@schmorb]

Does any metal trigger it, or just iron/ steel? Like if we had aluminum ingots and one steel would it ignore the aluminum?

[@PlayfulTechnology]

Yes, it will detect aluminium, but only at a closer detection range than a ferrous metal.

[@lwo7736]

I wonder why the enclosure and huge nuts don't constantly trigger it? Maybe a special material that locks the eddy currents down, maybe it's configured to be blind to the background currents and only trigger when there's a change

[@PlayfulTechnology]

That was exactly what I wondered too! I assume that it's calibrated to account for the metal casing. Either way, I think it's safe to avoid adding any further metal hardware in the vicinity.

[@reginacarrillo6465]

I feel like this is a dumb question, but im 100% new to all of this. What do you use as a power source? I learned the hard way that there is such a thing as too much power. I burned up a mechanism because it was plugged directly into the wall.

[@Ju-wy4yb]

Good question actually