NAVI-Embed

Dual-mode NFC firmware for LilyGO T-Embed CC1101 and T-Embed CC1101 Plus (ESP32-S3 + PN532 + ST7789).

It toggles on-the-fly between:

1. USB HID Keyboard: Standalone badge reader. Reads ISO14443A / MIFARE / NTAG cards and types the hexadecimal UID followed by Enter. Single-shot capture prevents duplicate keystrokes while the tag remains on the antenna.
2. libnfc Serial Bridge (pn532_uart over USB CDC): Transparent serial bridge for PC security auditing tools (nfc-list, mfoc, mfcuk, nfc-mfclassic) on Linux, Kali Linux, and VirtualBox VMs (/dev/ttyACM0 at 115200 baud). Uses single-shot atomic I2C reads to prevent byte-shift checksum errors.

Features a Copland OS inspired interface on the 320x170 ST7789 IPS display with real-time RX/TX frame counters.

---

Controls

Input	Action
Rotary Dial (CW)	Switch to LIBNFC BRIDGE mode
Rotary Dial (CCW)	Switch to HID KEYBOARD mode
Center Knob Click (<400ms)	Toggle operating mode
User Button Click (<400ms)	Toggle operating mode
Knob / Button Hold (>3s)	Deep Sleep power down

---

Installation

Option 1: MicroSD via bmorcelli / Launcher (Recommended)

1. Copy NAVI-Embed.bin to your MicroSD card.
2. Boot into bmorcelli / Launcher.
3. Select NAVI-Embed.bin and launch.

Option 2: Direct Flash via USB (Offset 0x0)

Windows (PowerShell):

python -m esptool --chip esp32s3 -p COMx -b 921600 write_flash 0x0 NAVI-Embed.bin

Linux / macOS:

esptool.py --chip esp32s3 -p /dev/ttyACM0 -b 921600 write_flash 0x0 NAVI-Embed.bin

---

Kali Linux / libnfc Setup

1. Forward the USB device (303a:1001) to the VM.
2. Disable ModemManager to prevent serial port lockouts:

   sudo systemctl stop ModemManager
   sudo systemctl disable ModemManager

3. Configure /etc/nfc/libnfc.conf:

   device.name = "LilyGO T-Embed PN532"
   device.connstring = "pn532_uart:/dev/ttyACM0"
   allow_autoscan = false
   allow_intrusive_scan = false

4. Switch T-Embed to MODE:[LIBNFC BRIDGE] and run:

   sudo nfc-list
   sudo mfoc -O dump.mfd

---

Hardware Pinout Reference

Function	Pin	Notes
PN532 I2C SDA / SCL	GPIO 18 / GPIO 8	100 kHz bus, Address 0x24
PN532 IRQ / Reset	GPIO 1 / GPIO 3	Active LOW IRQ
ST7789 MOSI / SCLK	GPIO 9 / GPIO 11	40 MHz SPI
ST7789 CS / DC / BL	GPIO 41 / GPIO 16 / GPIO 21	Backlight active HIGH
Encoder A / B / Key	GPIO 4 / GPIO 5 / GPIO 0	Pull-up enabled
User Button	GPIO 6	Pull-up enabled
Power Enable	GPIO 15 / GPIO 46	VDD enable (Standard & Plus)

---

Build from Source

git clone https://github.com/your-username/NAVI-Embed.git
cd NAVI-Embed
pio run

Generate the unified binary:

python -m esptool --chip esp32s3 merge_bin -o bin/NAVI-Embed.bin --flash_mode qio --flash_size 16MB 0x0 .pio/build/lilygo-t-embed-cc1101/bootloader.bin 0x8000 .pio/build/lilygo-t-embed-cc1101/partitions.bin 0x10000 .pio/build/lilygo-t-embed-cc1101/firmware.bin

---

License

MIT License.