# RFID-Transponder

## Overview

This project is a compact and versatile PCB design featuring an RFID/NFC tag IC. It includes components for writing and managing data on the RFID tag, modern power input options, and flexible microcontroller integration.

## Key Features

### RFID/NFC Tag Functionality

- Built-in RFID coil, designed using eDesignSuite by ST-Engineering.
- Integrated with the ST25DV04KC RFID/NFC Tag IC, offering:
  - 16 KB EEPROM for data storage.
  - Communication via the I2C bus.
- Data can be written to the tag using external devices, such as smartphones with RFID capabilities.

### Data Storage Support

- Includes a Micro SD card slot for additional data storage.
- Utilizes a 74LVC125 IC for safe voltage level shifting between the 5V logic of the microcontroller and the 3.3V logic of the Micro SD card.

### Power Input

- Powered via a USB-C port delivering 5V.
- Configured with 1 kΩ resistors on the CC pins to ensure USB-C standard compliance.

### Flexible Microcontroller Integration

- Designed around the AtmegaXX08 series of microcontrollers, specifically the Atmega3208.
- Compatible with other ICs in the same series and package.

### Connectivity

- Provides connectors for UPDI and UART for programming and debugging.
- Optional GPIO breakout for additional interfacing needs.

## Applications

- Use as an RFID/NFC tag in systems requiring dynamic, writable RFID data storage.
- Embedded designs requiring compact, integrated EEPROM and I2C functionality.
- Systems needing programmable and customizable tag IC solutions.

## Schematic