T-Mini E-Paper S3 Quick Start

Required Libraries

Copy the lib/ folder from the repository into your Arduino libraries directory, or install individually:

Library	Source
GxEPD2 (e-paper)	GitHub
RadioLib (SX1262 LoRa)	GitHub
PCF8563 (RTC)	GitHub
AceButton	GitHub
Adafruit NeoPixel	GitHub

---

Arduino

Arduino IDE

1. Install ESP32 Board Support

1. Open Arduino IDE → File → Preferences
2. Add to "Additional boards manager URLs":

   https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

3. Go to Tools → Board → Boards Manager, search esp32, install esp32 by Espressif Systems

2. Install Libraries

Copy all folders from the project lib/ directory into your Arduino libraries folder (e.g. C:\Users\YourName\Documents\Arduino\libraries).

3. Board Settings

Setting	Value
Board	ESP32S3 Dev Module
Port	Your COM port
USB CDC On Boot	Enabled
USB Mode	Hardware CDC and JTAG
USB Firmware MSC On Boot	Disabled
USB DFU On Boot	Disabled
CPU Frequency	240 MHz (WiFi)
Flash Mode	QIO 80 MHz
Flash Size	4 MB (32Mb)
Partition Scheme	Default 4MB with spiffs (1.5MB APP/1.5MB SPIFFS)
PSRAM	QSPI PSRAM
Upload Speed	921600

Note: Set USB CDC On Boot to Disabled when running on battery to avoid boot issues.

4. Upload

Connect via USB-C, open the example sketch, click Upload.
If upload fails, hold BOOT and press RST, release RST first, then start upload.

---

PlatformIO

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

   git clone https://github.com/Xinyuan-LilyGO/LilyGO-Mini-Epaper-S3.git

3. Open platformio.ini, uncomment the desired example environment
4. Click ✓ to build, connect the board, click → to upload

---

Examples

Example	Description
EPD_Display	E-paper display demo
LoRa_Send	LoRa transmit example
LoRa_Receive	LoRa receive example
RTC_Clock	PCF8563 real-time clock
Deep_Sleep	Deep sleep + wake-up
SD_Card	TF card read/write
Factory_Test	Full hardware test

---

This board uses a GxEPD2 e-paper panel. LVGL is not recommended here — use the board's GxEPD2 examples for display handling and partial refresh timing.

Notes:

• Run the EPD_Display and factory examples in the LilyGO-Mini-Epaper-S3 repo to exercise display, LoRa, RTC and SD features.
• Call a full refresh on first boot: display.display(false).
• For simple UIs on small e-paper, implement minimal draw/update routines with GxEPD2 instead of a full LVGL port.

Peripheral Examples

E-Paper Hello World (GxEPD2)

#include <GxEPD2_BW.h>
#include <Fonts/FreeMonoBold9pt7b.h>

// SPI pins — refer to pin_config.h for actual values
#define EPD_CS    10
#define EPD_DC     9
#define EPD_RST    8
#define EPD_BUSY   7

// 1.02-inch 128×80 e-paper
GxEPD2_BW<GxEPD2_102, GxEPD2_102::HEIGHT> display(
    GxEPD2_102(EPD_CS, EPD_DC, EPD_RST, EPD_BUSY));

void setup() {
    display.init(115200);
    display.setRotation(1);
    display.setFont(&FreeMonoBold9pt7b);
    display.setTextColor(GxEPD_BLACK);

    display.setFullWindow();
    display.firstPage();
    do {
        display.fillScreen(GxEPD_WHITE);
        display.setCursor(5, 30);
        display.print("T-Mini E-Paper");
        display.setCursor(5, 55);
        display.print("Hello World!");
    } while (display.nextPage());
}

void loop() {}

Partial Update (Low Power Refresh)

// Partial update only refreshes changed area — much faster and less flicker
display.setPartialWindow(0, 0, 128, 40);
display.firstPage();
do {
    display.fillScreen(GxEPD_WHITE);
    display.setCursor(5, 25);
    display.printf("Count: %d", count++);
} while (display.nextPage());

LoRa Send (SX1262)

#include <RadioLib.h>

// SPI and control pins — refer to pin_config.h
#define LORA_CS    SS
#define LORA_DIO1  33
#define LORA_RST   32
#define LORA_BUSY  34

SX1262 radio = new Module(LORA_CS, LORA_DIO1, LORA_RST, LORA_BUSY);

void setup() {
    Serial.begin(115200);
    int state = radio.begin(915.0);  // 868.0 for EU, 433.0 for Asia
    if (state == RADIOLIB_ERR_NONE) {
        Serial.println("LoRa initialized");
    }
}

void loop() {
    int state = radio.transmit("Hello from T-Mini E-Paper S3!");
    if (state == RADIOLIB_ERR_NONE) {
        Serial.println("Packet sent");
    }
    delay(5000);
}

LoRa Receive (SX1262)

#include <RadioLib.h>

SX1262 radio = new Module(LORA_CS, LORA_DIO1, LORA_RST, LORA_BUSY);

void setup() {
    Serial.begin(115200);
    radio.begin(915.0);
    radio.startReceive();
}

void loop() {
    String str;
    int state = radio.readData(str);
    if (state == RADIOLIB_ERR_NONE) {
        Serial.print("Received: ");
        Serial.println(str);
        Serial.print("RSSI: ");
        Serial.println(radio.getRSSI());
        radio.startReceive();
    }
    delay(10);
}

RTC — Set and Read Time (PCF8563)

#include <PCF8563.h>

PCF8563 rtc;

void setup() {
    Serial.begin(115200);
    Wire.begin();
    rtc.init();

    // Set time: 2026-01-01 12:00:00
    rtc.stopClock();
    rtc.setYear(26);
    rtc.setMonth(1);
    rtc.setDay(1);
    rtc.setHour(12);
    rtc.setMinut(0);
    rtc.setSecond(0);
    rtc.startClock();
}

void loop() {
    Time now = rtc.getTime();
    Serial.printf("20%02d-%02d-%02d %02d:%02d:%02d\n",
        now.year, now.month, now.day,
        now.hour, now.minute, now.second);
    delay(1000);
}

Deep Sleep + Wake by Timer

#include <esp_sleep.h>

#define SLEEP_SECONDS 60

void setup() {
    Serial.begin(115200);
    Serial.println("Woke up — running task...");

    // ... update e-paper display, send LoRa packet, etc. ...

    Serial.printf("Sleeping for %d seconds\n", SLEEP_SECONDS);
    esp_sleep_enable_timer_wakeup((uint64_t)SLEEP_SECONDS * 1000000ULL);
    esp_deep_sleep_start();
}

void loop() {}

---

FAQ

Q: Upload keeps failing — what should I do?
A: Hold BOOT and press RST once, release RST while still holding BOOT, then start the upload.

Q: No serial output from USB?
A: Set USB CDC On Boot to Enabled in Arduino IDE Tools.

Q: The e-paper display shows ghosting after many updates.
A: Perform a full refresh periodically (every ~10 partial updates) using display.setFullWindow() to clear ghosting.

Q: Which LoRa frequency should I use?
A: Use 915 MHz for North America, 868 MHz for Europe, 433 MHz for Asia. Match the frequency of your receiver.

Q: How do I check the hardware is working?
A: Flash the factory firmware test to verify all peripherals.