LilyGo T-Relay-8 is an ESP32 WiFi & BLE board equipped with eight 5V relays supporting up to 250V AC or 28V DC, as well as a 16-pin GPIO header for expansion.
The board offers a more compact solution than the usual two-board setups with an ESP32 board and a separate 8-relay “Arduino” module, and also integrates optocouplers for added security.
LilyGo T-Relay-8 Specifications:
- Wireless Module – ESP32-WROVER-E Module with ESP32 Dual-Core CPU with 2.4GHz WiFi 4 and Bluetooth 4.2 Connectivity, 4MB Flash, 8MB PSRAM
- Relay – 8x HRS4H-S-DC5V 5V relay up to 250VAC/10A or 28VDC/10A with octocoupler isolation, blue LEDs for status
- Expansion – 16 pin header (unpopulated) with GPIO, 3.3V and GND
- USB – 1x USB Type-C for programming via optional T-U2T dongle via CH9102 USB to TTL chip
- Miscellaneous – Reset Button, Red User LED
- Power – 12V to 24V via 2 pin terminal block
- Dimensions – 17 x 8.5 x 1.8 cm (the length is 17.5 cm if the PCB antenna of the ESP32 module is taken into account)
The board can be programmed with the Arduino or PlatformIO IDE, and LilyGo provides instructions and sample code to control relays via the Blynk IoT platform or a web server, as well as a simpler example of flasher type turning relays on and off in sequence. Note that like many LilyGo boards, T-Relay-8 does not come with a built-in USB-TTL chip, and instead users would need to connect the CH9102 chip-based T-U2T dongle to program the ESP32 . module.
LilyGo T-Relay-8 ESP32 board can be purchased with two unsoldered GPIO headers for $22.38 including shipping, or $27.98 if you don’t already have the required T-U2T dongle. If you can do with an ESP32 board with only 4 relays instead of 8, the T-Relay is sold for $10.37 more shipping.
Jean-Luc started CNX Software in 2010 on a part-time basis, before stepping down as Director of Software Engineering and starting writing daily news and reviews full-time later in 2011.