Interfacing RFID RC522 Reader and 16x2 LCD Display with Raspberry Pi Pico

This project demonstrates how to interface an RC522 RFID card reader/writer serial port interface module with a Raspberry Pi Pico and a 16x2 LCD display. When an RFID card is brought close to the reader, the system instantly detects the card, reads its unique ID, and outputs the information directly onto the LCD screen.
(Rev. 17-Jun-2026)

Categories | About |     |  

Parveen,

Introduction to the RFID and Raspberry Pi Pico Project

This project demonstrates how to interface an RC522 RFID card reader/writer serial port interface module with a Raspberry Pi Pico and a 16x2 LCD display. When an RFID card is brought close to the reader, the system instantly detects the card, reads its unique ID, and outputs the information directly onto the LCD screen.

How the System Works

The system operates seamlessly through a simple workflow when powered on:

  1. Initialization: When the system is turned on, indicator lights glow to verify that all connections are correct and secure.
  2. Standby Mode: The 16x2 LCD module initially displays a "Waiting" status message, waiting for a compatible RFID token.
  3. Detection and Reading: As soon as a white RFID card or key fob is brought close to the RC522 module, it is detected instantly.
  4. Output: The display updates immediately to show a "Card Detected" message alongside the specific unique identification (ID) number of the card.

Potential Applications

Integrating RFID reading capabilities with the Raspberry Pi Pico opens up many practical use cases. Such a setup can be effectively utilized to build and control:

  1. Automated door and security locks
  2. Digital attendance tracking systems
  3. User authentication and access control units

Hardware Connections and Source Code

The schematic circuit diagram, specific module details, and physical pin-to-port connections required for this setup are provided in the video's description. Because original code implementation resources combining the Raspberry Pi Pico, RC522, and a 16x2 LCD together are sparse online, custom software has been developed to achieve this functionality. For access to the complete source code, compiled installers, or further technical details, you can contact the creator directly via the information linked in the official video.

Circuit Diagram →
============
Make these connections.
RC522 RFID Reader Writer SPI Module with Card & Tag
====================================
PIN 36 Raspberry Pico to 3.3V pin on RC522 RFID Module
PIN 38 Raspberry Pico to GND pin on RC522 RFID Module
PIN 22 Raspberry Pico to SDA pin on RC522 RFID Module
PIN 21 Raspberry Pico to MISO pin on RC522 RFID Module
PIN 25 Raspberry Pico to MOSI pin on RC522 RFID Module
PIN 24 Raspberry Pico to SCK pin on RC522 RFID Module
16x2 LCD Display Module with I2C Interface
=============================
PIN 7 Raspberry Pico to SCL pin on 16x2 LCD Display Module
PIN 6 Raspberry Pico to SDA pin on 16x2 LCD Display Module
PIN 40 [5v can be tried] Raspberry Pico to VCC pin on 16x2 LCD Display Module
PIN 38 Raspberry Pico to GND pin on 16x2 LCD Display Module

Watch the Video

Please watch the following youtube video to see how to compile and build this project

Problem with new 16x2 Display

A new 16x2 display needs to be put into working mode sometimes. If nothing is displayed, turn the knob a few times, and try 5v power instead of 3.3v.

Compiled uf2 File

Write to us for customizations and compiled uf2 file!

Write to us for ANY customizations and obtaining your OWN UF2 for interfacing to this Module

This Blog Post/Article "Interfacing RFID RC522 Reader and 16x2 LCD Display with Raspberry Pi Pico" by Parveen is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.