LILYGO T-TWR Rev2.1

Overview

The LILYGO T-TWR Rev2.1 is an advanced development board tailored for amateur radio and APRS (Automatic Packet Reporting System) applications. It combines the ESP32-S3-WROOM-1-N16R8 (16MB flash, 8MB PSRAM) with a SA868 VHF/UHF wireless transceiver, enabling full two-way radio communication. A L76K multi-constellation GNSS module adds GPS, BDS (BeiDou), and GLONASS positioning with a built-in LNA and SAW filter for improved reception.

A 1.3-inch SH1106 OLED display (128×64 pixels) connected via I2C provides a compact UI for displaying frequency, GPS coordinates, and system status. Four buttons (PPT, Boot, PWR, Reset), a WS2812 RGB LED, and TF card slot complete the hardware. The AXP2102 power management unit supports operation from USB, 21700 cells, or 18650 cells via a spring connector.

Note that community firmware OpenRTX supports version 2.0 but not Rev2.1 as of the product listing. Compatible alternative projects include SoftRF Ham Edition, ESP32APRS, and ArcticTracker.

Firmware Compatibility

Compatible with Arduino IDE and ESP-IDF for custom firmware development. Community firmware options include SoftRF Ham Edition (APRS tracking), ESP32APRS (APRS node), and ArcticTracker. The GitHub repository at https://github.com/Xinyuan-LilyGO/T-TWR provides source code and documentation.

Flashing Guide

1. Install the ESP32 board package in Arduino IDE or set up ESP-IDF.
2. Connect via USB-C cable.
3. Hold BOOT and press RESET to enter download mode if needed.
4. Select ESP32-S3-WROOM-1 with 16MB flash and 8MB OPI PSRAM.
5. Flash the desired firmware (Arduino sketch, ESP-IDF binary, or community firmware binary).