Electronics Projects
RFID Door Lock
Open a latch with a servo when an authorised card is scanned.
Overview
An RC522 reads each card's ID; on a match a servo opens the latch, otherwise a buzzer sounds.
Build Steps
Wire the reader
Connect the RC522 to SPI and 3.3 V — never 5 V.
Add outputs
Wire the servo, an LED with a 220 Ω resistor and the buzzer.
Store allowed IDs
Keep authorised IDs in an array and compare each scan.
Drive the latch
On a match, open the servo, wait, close. Otherwise beep.
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