# RFID Relay Control

Day 74 of the 100 Days 100 IoT Projects collection. Board: Pi Pico.

An RFID card switches a relay and fan on the Pico 2 via MFRC522. Tap-to-power automation.

## How it works

An authorized RFID tap tells the Pico 2 to energize its relay, switching on whatever is wired to it — here, a fan. The MFRC522 handles card detection over SPI while the relay handles the heavy current. Tap-to-power: physical presence becomes the on switch.

## What you'll learn

- Tap-to-actuate design
- RFID plus relay integration
- Physical access control
- Presence-based switching

Full project (code, wiring diagram, Wokwi simulation): https://github.com/kritishmohapatra/100_Days_100_IoT_Projects/tree/main/RFID_Relay_Control_System

Summary by SkillShop. Code and diagrams belong to the original repo.