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
| MCU | ESP32 |
| FLASH | 4MB |
| PS RAM | 8MB |
| Bus Interfaces | UART, SPI, I2C, CAN, I2S, SDIO |
| Wireless | Wi-Fi 802.11 b/g/n |
| Bluetooth | BLE V4.2 |
| Onboard Functions | 4 Groups of relays |
| Optocoupler Isolation | 16 Expansion GPIO |
HRS4H-S-DC5V Relay: 4 Blue LEDs Relay Work Indicator
①K1 Relay: GPIO21
②K2 Relay: GPIO19
③K3 Relay: GPIO18
④K4 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.
Important Notes
- This product does not include a programmed download chip.
- To upload programs, a T-U2T Auto Downloader is required.
- If you don’t 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