LILYGO T-Echo Card: solar-powered LoRa board with nRF52840 for off-grid comms

LILYGO has unveiled a compact development board, the T-Echo Card, aimed at building devices for off-grid communication and navigation beyond cellular coverage. The newcomer pairs a Nordic Semiconductor nRF52840 wireless microcontroller with a Semtech SX1262 LoRa transceiver, while its slim enclosure is weatherproof and fitted with a solar panel to recharge the built-in 800 mAh battery.

The board supports a broad set of protocols: Bluetooth 5, NFC, Bluetooth Mesh, ANT, and 802.15.4 (Zigbee/Thread), along with LoRaWAN and GNSS via the L76K module. This makes the T-Echo Card suitable for exchanging text and voice messages, sharing location coordinates, tracking people or assets, and serving as a compact mesh network node.

At its core sits a 32-bit Arm Cortex-M4F microcontroller clocked at 64 MHz, with 1 MB of flash memory and 256 KB of RAM. Additional external SPI flash storage of 32 Mbit (model ZD25WQ32CEIGR) is also provided. Long-range connectivity is handled by the SX1262 transceiver with support for global LoRa frequency bands.

Other features include a tiny 0.42-inch OLED display for status information, a magnetic USB interface for charging and connectivity, a 9-axis motion sensor, a digital microphone, a speaker, and a multicolor LED for notifications. This combination makes the board suitable for wearables, trackers, and field communication kits powered by solar energy.