# LILYGO T-Relay 5V 8-Channel

> ESP32-WROVER-E development board with 8 optocoupler-isolated 5V relay channels (HRS4H-S-DC5V), Wi-Fi, BLE 4.2, 8MB PSRAM, and support for DC 12–24V power input for industrial automation.

## Quick Facts

- **Brand:** LILYGO
- **Board Type:** ESP32
- **Price:** ~$15.99
- **Product Readiness:** developer
- **CPU:** ESP32-WROVER-E
- **CPU Architecture:** Xtensa LX6 dual-core
- **PSRAM:** 8MB
- **Flash:** 4MB
- **Power:** 12-24V DC
- **Operating Voltage:** 3.3V

## Connectivity

- **Wifi:** 802.11 b/g/n
- **Bluetooth:** BLE 4.2

## Open Source

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

## Compatible Firmware

arduino, esp-idf, platformio, esphome

## Use Cases

- home-automation
- industrial-automation
- smart-building
- smart-switch
- hvac-control

## Components

- **ESP32-WROVER-E** (mcu): ESP32 module with 4MB Flash, 8MB PSRAM, integrated Wi-Fi b/g/n and BLE 4.2 — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32_datasheet_en.pdf&ref=openhardware.directory&product=lilygo-t-relay-5v-8-channel&source=md-export)
- **HRS4H-S-DC5V** (relay): 8-channel 5V coil relay with optocoupler isolation; switches AC 250V/DC 28V; LED indicator per channel — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.datasheetcafe.com%2Fhrs4h-datasheet-relay%2F&ref=openhardware.directory&product=lilygo-t-relay-5v-8-channel&source=md-export)

## Protocols

- **UART**
- **SPI**
- **I2C**
- **CAN**
- **I2S**

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| IO33 | — | — | — |
| IO32 | — | — | — |
| IO13 | — | — | — |
| IO12 | — | — | — |
| IO21 | — | — | — |
| IO19 | — | — | — |
| IO18 | — | — | — |
| IO05 | — | — | — |

## Available Software

- **[Arduino IDE](https://openhardware.directory/r?to=https%3A%2F%2Fwww.arduino.cc%2F&ref=openhardware.directory&product=lilygo-t-relay-5v-8-channel&source=md-export)**
- **[ESPHome](https://openhardware.directory/r?to=https%3A%2F%2Fesphome.io%2F&ref=openhardware.directory&product=lilygo-t-relay-5v-8-channel&source=md-export)**

## Description

## Overview

The LILYGO T-Relay 5V 8-Channel is an ESP32-based relay control board featuring eight optocoupler-isolated HRS4H-S-DC5V relays, each with an individual LED indicator. The ESP32-WROVER-E module provides Wi-Fi and Bluetooth connectivity alongside 8MB PSRAM for data-intensive tasks. Each relay channel is independently addressable via GPIO and can switch AC loads up to 250V or DC loads up to 28V. The board accepts DC 12–24V power input, making it suitable for direct integration into industrial control cabinets and smart home automation panels without additional voltage conversion.

## Where to Buy

- [LILYGO Official](https://openhardware.directory/r?to=https%3A%2F%2Flilygo.cc%2Fproducts%2Ft-relay-5v-8-channel-relay&ref=openhardware.directory&product=lilygo-t-relay-5v-8-channel&source=md-export) — $15.99

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Flilygo.cc%2Fproducts%2Ft-relay-5v-8-channel-relay&ref=openhardware.directory&product=lilygo-t-relay-5v-8-channel&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FXinyuan-LilyGO%2FLilyGo-T-Relay&ref=openhardware.directory&product=lilygo-t-relay-5v-8-channel&source=md-export)

## Tags

`esp32`, `relay`, `automation`, `industrial`, `8-channel`, `optocoupler`

## Images

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