T-Relay S3 Quick Start

Required Libraries

Library	Version	Source
(No external libraries required)	—	—

---

Arduino

PlatformIO (Recommended)

1. Install VS Code and the PlatformIO IDE extension
2. Clone the repository:

   git clone https://github.com/Xinyuan-LilyGO/T-Relay-S3.git

3. Open platformio.ini and select the target example
4. Click ✓ to build, connect via USB-C, click → to upload

---

Arduino IDE

Board Settings

Setting	Value
Board	ESP32S3 Dev Module
Upload Speed	921600
USB CDC On Boot	Enable
CPU Frequency	240 MHz (WiFi)
Flash Size	16 MB (128Mb)
Partition Scheme	16M Flash (3MB APP/9.9MB FATFS)
PSRAM	OPI PSRAM

---

Peripheral Examples

Basic Relay Control

#define RELAY1  21
#define RELAY2  47
#define RELAY3  48
#define RELAY4   3
#define RELAY5  14
#define RELAY6  13
#define RELAY7  12
#define RELAY8  11

void setup() {
    for (int pin : {RELAY1, RELAY2, RELAY3, RELAY4,
                    RELAY5, RELAY6, RELAY7, RELAY8}) {
        pinMode(pin, OUTPUT);
        digitalWrite(pin, LOW);
    }
}

void loop() {
    digitalWrite(RELAY1, HIGH);
    delay(500);
    digitalWrite(RELAY1, LOW);
    delay(500);
}

---

FAQ

Q: Upload keeps failing?
A: Hold BOOT, press and release RST, then release BOOT to enter download mode.

Q: What is the difference from T-Relay?
A: T-Relay S3 uses ESP32-S3 (faster, more GPIO), supports 8 relay channels (vs 4 on the original), and has USB-C.