LILYGO Launches Eight-Channel ESP32-Powered T-Relay Board, with Unusual Not-a-USB Port

Offering eight optoisolated relay outputs and access to otherwise-unused pins, this compact board could prove handy for home automation.

Embedded electronics specialist LILYGO has launched its first eight-channel relay board, driven by an Espressif ESP32-WROVER-E module — and requiring, unusually, a specific dongle for programming.

Designed as a follow-up to the company's earlier four-channel T-Relay, and brought to our attention by CNX Software, the new T-Relay-8 offers double the outputs — each of which supports up to 250V AC at 10A or 28V DC at 10A switching voltage, with individual per-channel blue LEDs for status reporting. The on-board ESP32-WROVER-E offers a dual-core processor, 8MB of pseudo-static RAM (PSRAM), and 4MB of flash, along with 802.11b/g/n Wi-Fi and Bluetooth 4.2 Low Energy (BLE) wireless connectivity.

LILYGO has given some thought to the layout of the rectangular board: All relays, accessed via screw terminals, are found at one side of the board opposite a 12-24V DC power input, with full optoisolation to the microcontroller. The module's spare pins, meanwhile, are brought out to an unpopulated header, allowing for additional expansion in the future.

There's an interesting twist in the board's design, however. What appears to be a USB Type-C port to the bottom-right, near the power input, is actually a repurposed mechanical socket which hosts the board's TTL serial port. Connecting a USB cable, then, does nothing; instead, the board is programmed using LILYGO's custom T-U2T USB to TTL dongle — a compact device which sits between a real USB Type-C cable and the mechanical-only serial port on the company's boards.

LILYGO has not yet listed the board for sale on its Tindie store, but has begun shipping it via AliExpress for $25.98 board-only or $32.98 with bundled T-U2T dongle.

Additional information, including instructions on programming the board via the Arduino IDE or PlatformIO, are available on LILYGO's GitHub repository.

Gareth Halfacree
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire:
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