# LILYGO T-Relay S3

> ESP32-S3 board with 6 onboard relays, 16MB flash, 8MB PSRAM, WiFi, and BLE for ESPHome smart home automation, controlling lights, appliances, and HVAC systems.

## Quick Facts

- **Brand:** LILYGO
- **Board Type:** dev-board
- **Price:** ~$23.99
- **Product Readiness:** developer
- **CPU:** Xtensa LX7 dual-core @ 240MHz, FPU, AI instructions
- **CPU Architecture:** Xtensa LX7
- **CPU Cores:** 2
- **RAM:** 512KB SRAM
- **PSRAM:** 8MB
- **Flash:** 16MB
- **USB:** USB-C
- **Power:** 5V
- **Operating Voltage:** 3.3V
- **Antenna:** Built-in PCB antenna

## Connectivity

- **Wifi:** 802.11 b/g/n
- **Bluetooth:** BLE 5.0

## Open Source

- **Firmware:** Yes
- **Schematics:** Yes
- **PCB Layout:** No

## Certifications

CE, FCC

## Compatible Firmware

arduino, esp-idf, esphome, tasmota

## Use Cases

- smart-switch
- home-automation
- industrial-automation

## Components

- **ESP32-S3-WROOM-1U** (mcu): Xtensa LX7 dual-core at 240MHz with 16MB flash, 8MB PSRAM, WiFi 802.11 b/g/n, and BLE 5.0. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32-s3-wroom-1_wroom-1u_datasheet_en.pdf&ref=openhardware.directory&product=lilygo-t-relay-s3&source=md-export)
- **relay** (relay): Six electromechanical relays for switching AC/DC loads up to 10A, each independently controlled by a GPIO pin. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FXinyuan-LilyGO%2FT-Relay-S3&ref=openhardware.directory&product=lilygo-t-relay-s3&source=md-export)

## Protocols

- **I2C**: SDA: GPIO8, SCL: GPIO9
- **UART**: TX: GPIO43, RX: GPIO44

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| GPIO8 | I2C SDA | I2C | digital-input, digital-output |
| GPIO9 | I2C SCL | I2C | digital-input, digital-output |

## Description

## Overview

The LILYGO T-Relay S3 brings the ESP32-S3's processing power to relay-based home automation, featuring 6 independent relay channels on a single board. With 16MB flash and 8MB PSRAM, it runs ESPHome or Tasmota for immediate Home Assistant integration, turning it into a six-zone smart switch controller.

The 6 relays can independently control AC or DC loads such as lighting circuits, appliances, motorized blinds, irrigation valves, or HVAC zones. The ESP32-S3's WiFi enables OTA firmware updates and MQTT communication, while BLE 5.0 allows local control from smartphones without a hub.

An expansion variant (T-Relay Chain) allows chaining multiple boards together for higher channel counts, and a W5500 Ethernet shield is available for wired network connectivity in environments where WiFi reliability is critical. ESPHome configuration is straightforward, making this board accessible to Home Assistant users without embedded programming experience.

## Where to Buy

- [LILYGO Official](https://openhardware.directory/r?to=https%3A%2F%2Flilygo.cc%2Fproducts%2Ft-relay-s3&ref=openhardware.directory&product=lilygo-t-relay-s3&source=md-export) — $23.99

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Flilygo.cc%2Fproducts%2Ft-relay-s3&ref=openhardware.directory&product=lilygo-t-relay-s3&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FXinyuan-LilyGO%2FT-Relay-S3&ref=openhardware.directory&product=lilygo-t-relay-s3&source=md-export)

## Tags

`esp32-s3`, `relay`, `esphome`, `tasmota`, `home-automation`, `smart-switch`, `lilygo`

## Images

![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/1e4bee84fae0.jpg)
![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/1bbbd2d7f209.jpg)
![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/13a3a3ef2156.jpg)
![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/39bd19bbd2e5.jpg)
![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/9105ab893a4c.jpg)
![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/e46df382d8c5.jpg)
![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/76d6e3f99a47.jpg)
![LILYGO T-Relay S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-relay-s3/aa15f39401df.png)

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