ST25TB RFID Reader

A Rust firmware for reading and writing ST25TB RFID chips (commonly used in printer cartridges) using the LilyGO T-Embed CC1101 device.

Photos

   

Menu Screen                         Chip Data View

Features

• Read ST25TB chips - Full chip dump (up to 256 blocks)
• Write ST25TB chips - Write modified data back to chip
• Serial Dump - Export chip data via serial monitor
• Serial Load - Import chip data by pasting hex dump
• TFT Display UI - Menu navigation with rotary encoder
• Audio Feedback - Beep on successful operations

Hardware

Required

• LilyGO T-Embed CC1101 (ESP32-S3)
• PN532 NFC Module (connected via I2C)

Pin Configuration

Function	GPIO
PN532 SDA	GPIO8
PN532 SCL	GPIO18
PN532 IRQ	GPIO17
PN532 RST	GPIO45
Display CS	GPIO41
Display DC	GPIO16
Display BL	GPIO21
Encoder A	GPIO4
Encoder B	GPIO5
Encoder BTN	GPIO0
Back Button	GPIO6
Power Enable	GPIO15

Building

Prerequisites

1. Install Rust and ESP toolchain:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
cargo install espup
espup install

2. Source the environment:

source ~/export-esp.sh

Build Commands

Using just (recommended):

# Install just
cargo install just

# Build
just build

# Flash and monitor
just flash

# Monitor only
just monitor

Or manually:

# Build
cargo build --release

# Flash
cargo espflash flash --port /dev/cu.usbmodem1201 --release

# Monitor
espflash monitor --port /dev/cu.usbmodem1201 --non-interactive

Releases

Pre-built binaries are available in Releases:

File	Description
rfid-reader.bin	App binary for Launcher bootloader
rfid-reader-full.bin	Full firmware with bootloader (flash at 0x0)

Using Launcher: Copy rfid-reader.bin to SD card, select from Launcher menu SD. Firmware app and reboot.

Standalone flash:

esptool.py write_flash 0x0 rfid-reader-full.bin

Usage

Menu Navigation

• Rotate encoder - Navigate menu / scroll data
• Press encoder - Select / toggle edit mode
• Back button - Go back / cancel

Reading a Chip

1. Select "Read Chip" from menu
2. Place ST25TB chip on PN532 antenna
3. Wait for beep (success) or error message

Writing a Chip

1. First read or load chip data
2. Select "Write Chip" from menu
3. Place same chip on antenna
4. Wait for verification

Serial Dump/Load

Export dump:

1. Select "Dump Serial"
2. Copy output from serial monitor

Import dump:

1. Select "Load Serial"
2. Paste data in format:

B000: 0F FF FF FF
B001: 9F FF FF FF
...
END

3. Type END and press Enter

Supported Chips

• ST25TB04K (512 bytes)
• ST25TB512
• ST25TB02K
• SRI512 / SRIX4K (ISO14443-B)

Project Structure

src/
├── main.rs           # Application entry & UI logic
├── board.rs          # Pin definitions
├── drivers/
│   ├── pn532.rs      # PN532 NFC driver (I2C)
│   └── audio.rs      # I2S audio (beep)
├── protocol/
│   └── st25tb.rs     # ST25TB read/write protocol
└── ui/
    ├── display.rs    # TFT display rendering
    └── editor.rs     # Chip data editor

Technical Details

• MCU: ESP32-S3 (Dual-core LX7, 240MHz)
• Framework: esp-hal (bare metal, no_std)
• Display: ST7789V 170x320 TFT
• NFC: PN532 via I2C at 100kHz
• Protocol: ISO14443-B

Known Issues

1. "Observer Effect" - Device may only work reliably with serial monitor connected (USB power initialization quirk)
2. PN532 Wakeup - First SAM config may fail; firmware retries automatically

License

MIT License - see LICENSE file.

Contributing

Contributions welcome! Please open an issue or PR.

Acknowledgments

• esp-hal - ESP32 Hardware Abstraction Layer
• LilyGO - Hardware documentation
• PN532 Datasheet
• ST25TB Datasheet