T-Connect Quick Start

Required Libraries

Library	Version	Source
RadioLib	Latest	GitHub
TFT_eSPI	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:

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

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

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Arduino IDE

1. Install ESP32 Board Support

1. Open Arduino IDE → File → Preferences
2. Add to "Additional Board 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. Board Settings

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

3. Upload

Connect via USB-C, open an example, and click Upload.

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Peripheral Examples

RS485 Communication

// RS485 channel 1: TX=4, RX=5
HardwareSerial rs485(1);

void setup() {
  Serial.begin(115200);
  rs485.begin(9600, SERIAL_8N1, 5, 4); // RX, TX
}

void loop() {
  rs485.print("Hello RS485\r\n");
  delay(1000);
  while (rs485.available()) {
    Serial.write(rs485.read());
  }
}

CAN Bus (TWAI)

#include <driver/twai.h>

// CAN TX=4, RX=5 (shared with RS485 channel 1 — configure only one at a time)
void setup() {
  Serial.begin(115200);
  twai_general_config_t g_config = TWAI_GENERAL_CONFIG_DEFAULT(GPIO_NUM_4, GPIO_NUM_5, TWAI_MODE_NORMAL);
  twai_timing_config_t  t_config = TWAI_TIMING_CONFIG_500KBITS();
  twai_filter_config_t  f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();
  twai_driver_install(&g_config, &t_config, &f_config);
  twai_start();
  Serial.println("CAN ready");
}

void loop() {
  twai_message_t msg;
  msg.identifier = 0x123;
  msg.data_length_code = 4;
  msg.data[0] = 0xDE; msg.data[1] = 0xAD;
  msg.data[2] = 0xBE; msg.data[3] = 0xEF;
  twai_transmit(&msg, pdMS_TO_TICKS(1000));
  delay(1000);
}

Relay Control

// Relay control pin — check utilities.h for your board revision
#define RELAY_PIN  15

void setup() {
  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW); // relay off
}

void loop() {
  digitalWrite(RELAY_PIN, HIGH); // relay on
  delay(2000);
  digitalWrite(RELAY_PIN, LOW);  // relay off
  delay(2000);
}

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FAQ

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