T-Watch S3 Plus Quick Start

Dependencies

Library	Version	Source
TTGO_TWatch_Library	latest (branch: t-watch-s3)	GitHub
RadioLib	latest	GitHub
XPowersLib	latest	GitHub

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Arduino

PlatformIO (Recommended)

1. Install VS Code and the PlatformIO IDE extension
2. Clone the repository (branch t-watch-s3):

   git clone -b t-watch-s3 https://github.com/Xinyuan-LilyGO/TTGO_TWatch_Library.git

3. Open platformio.ini, uncomment the T-Watch-S3-Plus environment
4. Click ✓ to compile, connect USB-C, click → to upload

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Arduino IDE

Board Settings

Setting	Value
Board	ESP32S3 Dev Module
Upload Speed	921600
USB Mode	UART0/Hardware CDC
USB CDC On Boot	Enabled
CPU Frequency	240 MHz (WiFi)
Flash Mode	QIO 80 MHz
Flash Size	16MB (128Mb)
Partition Scheme	16M Flash (3MB APP/9.9MB FATFS)
PSRAM	OPI PSRAM

Steps

1. Install Arduino IDE and add ESP32 board support: https://espressif.github.io/arduino-esp32/package_esp32_index.json
2. Clone the repository (branch t-watch-s3) and open an example
3. In config.h ensure LILYGO_WATCH_2024_PLUS or the appropriate macro is defined
4. Apply the board settings above and click Upload

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LVGL

T-Watch S3 Plus uses LVGL v8 via the TTGO_TWatch_Library. Call watch->lvgl_begin() to initialize display, flush callback, and touch input automatically.

Hello World

#include "LilyGoWatch.h"

TTGOClass *watch;

void setup() {
    watch = TTGOClass::getWatch();
    watch->begin();
    watch->openBL();
    watch->lvgl_begin();

    lv_obj_t *label = lv_label_create(lv_scr_act());
    lv_label_set_text(label, "T-Watch S3 Plus");
    lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
}

void loop() {
    lv_task_handler();
    delay(5);
}

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Peripheral Examples

Display (ST7789 — TTGO_TWatch_Library)

#include "LilyGoWatch.h"

TTGOClass *watch;

void setup() {
    watch = TTGOClass::getWatch();
    watch->begin();
    watch->openBL();
    watch->tft->fillScreen(TFT_BLACK);
    watch->tft->setTextColor(TFT_WHITE, TFT_BLACK);
    watch->tft->setTextSize(2);
    watch->tft->setCursor(20, 100);
    watch->tft->print("T-Watch S3 Plus");
}

void loop() {}

GPS (MIA-M10Q — TinyGPSPlus)

#include <TinyGPSPlus.h>
#include <HardwareSerial.h>

// Check TTGO_TWatch_Library config for GPS UART pins
#define GPS_RX  10
#define GPS_TX  11

TinyGPSPlus gps;
HardwareSerial GPSSerial(1);

void setup() {
    Serial.begin(115200);
    GPSSerial.begin(38400, SERIAL_8N1, GPS_RX, GPS_TX);
}

void loop() {
    while (GPSSerial.available()) gps.encode(GPSSerial.read());
    if (gps.location.isUpdated()) {
        Serial.printf("Lat: %.6f  Lon: %.6f\n", gps.location.lat(), gps.location.lng());
    }
}

LoRa (SX1262 — RadioLib)

#include <RadioLib.h>

#define LORA_CS    36
#define LORA_IRQ   45
#define LORA_RST   42
#define LORA_BUSY  46

SX1262 radio = new Module(LORA_CS, LORA_IRQ, LORA_RST, LORA_BUSY);

void setup() {
    Serial.begin(115200);
    int state = radio.begin(915.0, 125.0, 9, 7, RADIOLIB_SX126X_SYNC_WORD_PRIVATE, 22);
    if (state != RADIOLIB_ERR_NONE) Serial.printf("LoRa init failed: %d\n", state);
}

void loop() {
    radio.transmit("Hello T-Watch S3 Plus");
    delay(2000);
}

PMU (AXP2101 — XPowersLib)

#include "LilyGoWatch.h"

TTGOClass *watch;

void setup() {
    watch = TTGOClass::getWatch();
    watch->begin();
    Serial.printf("Battery: %u mV\n", watch->power->getBattVoltage());
    Serial.printf("Charging: %s\n", watch->power->isCharging() ? "Yes" : "No");
}

void loop() {}

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FAQ

Q: What is new compared to T-Watch S3? A: T-Watch S3 Plus adds GPS (MIA-M10Q) and larger battery capacity.

Q: Cannot upload? A: Hold BOOT, press RST once, release BOOT, then retry uploading.