Learn how to build a physical version of the NYT "Connections" Puzzle / Only Connect "Connecting Wall" using 16 MFRC522 RFID readers and an ESP32 or Arduino microcontroller.
This simple word puzzle requires you to sort cards into four groups, each containing four elements with a common connection between them.... simple, right?! The system has an easy training function to assign new groups to cards, making an infinitely replayable game - a fun project for use in a school, as an activity at an event, or at an escape room!

00:00:00 - 00:00:56 Introduction
00:00:57 - 00:01:04 Play along!
00:01:05 - 00:03:48 Solving the puzzle
00:03:49 - 00:06:51 Component Overview
00:06:52 - 00:10:31 SPI interface
00:10:32 - 00:12:00 The problem with counterfeit MFRC522 readers
00:12:01 - 00:14:52 Using multiplexers to isolate readers
00:14:53 - 00:15:40 Wiring diagram
00:15:41 - 00:16:21 Schematic and PCB design in EasyEDA
00:16:22 - 00:19:54 Writing group data to RFID cards
00:19:55 - 00:42:23 ESP32 Code listing
00:42:24 - 00:44:21 Wrapup

More details and downloads for this tutorial, and all the other #playful #technology projects on this channel, can be found on my Patreon page at   / playfultech