LILYGO T3 S3 LR1121

Overview

The LILYGO T3 S3 LR1121 is a LoRa development board built around the ESP32S3FH4R2 and the Semtech LR1121 multi-band transceiver. The LR1121 is notable for supporting both sub-GHz frequencies (830–940MHz) and 2.4GHz in a single chip, making this board one of the most flexible LoRa platforms for multi-region deployments without hardware changes.

The board includes a 0.96-inch SSD1306 OLED display (128×64 pixels) via I2C for local status display, a microSD card slot for data logging, and a LiPo battery connector with charging support for portable operation. Physical dimensions are 66×36mm with BOOT and Reset buttons for easy firmware management.

An optional MVSRE expansion board variant ($32.76) extends the hardware capabilities. The board is rated 4.5/5 stars by customers for its multi-band flexibility and compact design.

Firmware Compatibility

Compatible with Arduino IDE and ESP-IDF. The GitHub repository at https://github.com/Xinyuan-LilyGO/LilyGo-LoRa-Series provides examples for LR1121 operation across different frequency bands, point-to-point LoRa, and LoRaWAN connectivity.

Flashing Guide

1. Install the ESP32 board package in Arduino IDE 2.x.
2. Connect via USB-C cable.
3. Hold BOOT and press RESET to enter download mode if needed.
4. Select ESP32-S3 Dev Module with 4MB flash and 2MB PSRAM.
5. Use the LilyGo-LoRa-Series examples for LR1121 initialization and frequency configuration.