T-Encoder Pro Quick Start

Required Libraries

Library	Version	Source
TFT_eSPI	Latest	GitHub
LVGL	8.x	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-Encoder-Pro.git

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

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Arduino IDE

Board Settings

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

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LVGL

T-Encoder Pro uses a round GC9A01 TFT (240×240). LVGL 8.x works via TFT_eSPI.

#include <lvgl.h>
#include <TFT_eSPI.h>

static lv_disp_draw_buf_t draw_buf;
static lv_color_t buf[240 * 10];
TFT_eSPI tft;

void my_disp_flush(lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p) {
  uint32_t w = area->x2 - area->x1 + 1;
  uint32_t h = area->y2 - area->y1 + 1;
  tft.startWrite();
  tft.setAddrWindow(area->x1, area->y1, w, h);
  tft.pushColors((uint16_t *)&color_p->full, w * h, true);
  tft.endWrite();
  lv_disp_flush_ready(disp);
}

void setup() {
  tft.begin();
  tft.setRotation(0);
  lv_init();
  lv_disp_draw_buf_init(&draw_buf, buf, NULL, 240 * 10);

  static lv_disp_drv_t disp_drv;
  lv_disp_drv_init(&disp_drv);
  disp_drv.hor_res = 240;
  disp_drv.ver_res = 240;
  disp_drv.flush_cb = my_disp_flush;
  disp_drv.draw_buf = &draw_buf;
  lv_disp_drv_register(&disp_drv);

  lv_obj_t *label = lv_label_create(lv_scr_act());
  lv_label_set_text(label, "T-Encoder Pro");
  lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
}

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

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Peripheral Examples

Round Display (GC9A01)

#include <TFT_eSPI.h>

TFT_eSPI tft;

void setup() {
  tft.begin();
  tft.setRotation(0);
  tft.fillScreen(TFT_BLACK);
  tft.setTextColor(TFT_WHITE, TFT_BLACK);
  tft.setTextSize(2);
  tft.drawString("Encoder Pro", 55, 110);
}

void loop() {}

Rotary Encoder

// Encoder A/B/Button pins — check utilities.h for your build
#define ENC_A    0
#define ENC_B    2
#define ENC_BTN  1

volatile int encoderPos = 0;

void IRAM_ATTR onEncoderA() {
  if (digitalRead(ENC_A) == digitalRead(ENC_B)) encoderPos++;
  else encoderPos--;
}

void setup() {
  Serial.begin(115200);
  pinMode(ENC_A, INPUT_PULLUP);
  pinMode(ENC_B, INPUT_PULLUP);
  pinMode(ENC_BTN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(ENC_A), onEncoderA, CHANGE);
}

void loop() {
  Serial.print("Position: ");
  Serial.println(encoderPos);
  if (digitalRead(ENC_BTN) == LOW) {
    Serial.println("Button pressed");
    delay(200);
  }
  delay(100);
}

PMU (via XPowersLib)

#include <XPowersLib.h>

XPowersPMU pmu;

void setup() {
  Serial.begin(115200);
  Wire.begin();
  if (!pmu.begin(Wire, AXP2101_SLAVE_ADDRESS)) {
    Serial.println("PMU init failed");
    return;
  }
  Serial.print("Battery voltage: ");
  Serial.print(pmu.getBattVoltage());
  Serial.println(" mV");
}

void loop() {
  delay(1000);
}

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FAQ

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

Q: What display does T-Encoder Pro use?
A: T-Encoder Pro uses a round GC9A01 TFT display (240 × 240) similar to T-Encoder, but adds extra peripherals like a PMU and additional encoder steps.