LILYGO T-Echo

Overview

The LILYGO T-Echo is a distinctive development board that uses the Nordic nRF52840 instead of the typical ESP32, making it one of the few LILYGO boards without WiFi. The nRF52840 offers Bluetooth 5.0, USB, and NFC in an ARM Cortex-M4 package with excellent low-power characteristics — sleep current is just 0.25mA, making it ideal for battery-powered tracking devices that need to run for weeks or months.

The SX1262 LoRa transceiver enables long-range mesh networking through Meshtastic or point-to-point communication through SoftRF. The L76K multi-constellation GNSS module provides GPS, BDS, and GLONASS positioning. An e-ink display shows location, message, or status information without consuming power when the display is static. An optional BME280 variant adds temperature, humidity, and pressure sensing.

The board ships in multiple frequency variants (433, 868, 915MHz, and 920–923MHz for Japan certification) and multiple colors (White, Black, Grey, Brown). Regional warehouse options are available for the US, Germany/Europe, and Canada. The Adafruit nRF52 bootloader is pre-installed, enabling straightforward Arduino-compatible programming.

Firmware Compatibility

The T-Echo is one of the officially supported Meshtastic devices. It is also compatible with SoftRF for aviation and GPS tracking applications. For custom development, the Adafruit nRF52 Arduino core is the easiest path; the nRF5-SDK is available for advanced features including NFC. Required libraries are available in the GitHub repository at https://github.com/Xinyuan-LilyGO/T-Echo.

Flashing Guide

1. For Meshtastic: use the Meshtastic web flasher at flasher.meshtastic.org — select T-Echo and flash via USB-C.
2. For Arduino: install the Adafruit nRF52 board package in Arduino IDE, select "Adafruit Feather nRF52840" or the T-Echo specific board definition.
3. The board ships with the Adafruit nRF52 bootloader; double-press RESET to enter bootloader mode (LED will breathe).
4. Drag and drop a .uf2 firmware file onto the USB mass storage device that appears, or use Arduino IDE to upload.