LilyGO T-Relay 4-Channel Relay Module is a versatile and powerful ESP32-based relay board designed for IoT, smart home automation, and industrial control. With 4 relays, optocoupler isolation, and 16 expansion GPIOs, this relay module supports a wide range of communication protocols including UART, SPI, I2C, CAN, I2S, and SDIO. It offers seamless wireless control via Wi-Fi 802.11 b/g/n and Bluetooth V4.2 BR/EDR & BLE, making it ideal for both industrial and hobbyist projects, including LoRa mesh networks and ESP32 automation systems.

Specifications

HRS4H-S-DC5V Relay: 4 Blue LEDs Relay Work Indicator
K1 Relay: GPIO21
K2 Relay: GPIO19
K3 Relay: GPIO18
K4 Relay: GPIO05

Support T-U2T Upload Tool:
Computer USB Type-C data cable Connect to T-U2T USB to TTL downloader for programming. Fast, reliable, and compatible with all T-Relay ESP32 modules. USB cable also powers the board directly.

Technology Support [Github]

If you need technical support please check the link to find more details.

T-Relay GitHub Repository

Important Notes

• This product does not include a programmed download chip.
• To upload programs, a T-U2T Auto Downloader is required.
• If you dont have the T-U2T, you will need to purchase it separately.
• If you already own a T-U2T, it is compatible with all T-Relay series products.

Applications

• Smart Control: Ideal for smart home projects, industrial automation, and remote relay switching using ESP32 and Wi-Fi/Bluetooth connectivity.
• Relay Control: Perfect for controlling high-power devices with low-power microcontrollers like ESP32, using GPIO and optocoupler isolation for safety.
• IoT Applications: Use in Wi-Fi and Bluetooth-based IoT systems, including LoRa mesh networks, MQTT integration, and Node-RED dashboards.

Size

T-Relay W5500 Shield

More Details

Pin Diagram

Includes:

T-Relay

• 1 x Relay Module (ESP32-based)
• 2 x Pin Headers

T-Relay T-U2T Kit

• 1 x Relay Module
• 2 x Pin Headers
• 1 x T-U2T USB to TTL Downloader

T-Relay W5500 Shield