T-Echo Card Quick Start

Required Libraries

Library	Version	Source
RadioLib	Latest	GitHub
Adafruit_EPD	Latest	GitHub

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Arduino

PlatformIO (Recommended)

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

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

3. Open platformio.ini and select the T-Echo-Card environment
4. Click ✓ to build, click → to upload

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Arduino IDE

Board Settings

Setting	Value
Board	Adafruit Feather nRF52840 Express
Upload Speed	115200

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Peripheral Examples

E-Paper Display (Adafruit_EPD)

#include <Adafruit_EPD.h>
#include <SPI.h>

#define EPD_CS     33
#define EPD_DC     10
#define EPD_RESET  2
#define EPD_BUSY   3

Adafruit_IL0373 epd(212, 104, EPD_DC, EPD_RESET, EPD_CS, -1, EPD_BUSY);

void setup() {
    epd.begin();
    epd.clearBuffer();
    epd.setCursor(10, 10);
    epd.setTextColor(EPD_BLACK);
    epd.setTextSize(2);
    epd.print("T-Echo Card");
    epd.display();
}

void loop() {}

LoRa (SX1262 — RadioLib)

#include <RadioLib.h>

#define LORA_CS    24
#define LORA_IRQ   25
#define LORA_RST   26
#define LORA_BUSY  17

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() {
    int state = radio.transmit("Hello T-Echo Card");
    Serial.printf("TX state: %d\n", state);
    delay(2000);
}

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FAQ

Q: Upload keeps failing?
A: Double-tap the reset button to enter bootloader mode (LED blinks slowly).

Q: What form factor is T-Echo Card?
A: T-Echo Card is a credit-card-sized form factor board with integrated LoRa, nRF52840, and e-paper display for ultra-compact wearable and carry-along applications.