T-Embed Si4732 Quick Start

Required Libraries

Library	Version	Source
TFT_eSPI	Latest	GitHub
SI4735	Latest	GitHub
FastLED	Latest	GitHub
LVGL	8.x	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-Embed-Si4732.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-Embed Si4732 uses a 1.9-inch ST7789V TFT (320×170). LVGL 8.x is pre-configured via TFT_eSPI in the official repository.

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

static lv_disp_draw_buf_t draw_buf;
static lv_color_t buf[320 * 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(1);
  lv_init();
  lv_disp_draw_buf_init(&draw_buf, buf, NULL, 320 * 10);

  static lv_disp_drv_t disp_drv;
  lv_disp_drv_init(&disp_drv);
  disp_drv.hor_res = 320;
  disp_drv.ver_res = 170;
  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-Embed Si4732");
  lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
}

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

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Peripheral Examples

Display (ST7789V)

#include <TFT_eSPI.h>

TFT_eSPI tft;

void setup() {
  tft.begin();
  tft.setRotation(1);
  tft.fillScreen(TFT_BLACK);
  tft.setTextColor(TFT_GREEN, TFT_BLACK);
  tft.setTextSize(2);
  tft.drawString("T-Embed Si4732", 30, 75);
}

void loop() {}

Si4732 AM/FM Radio

#include <SI4735.h>

SI4735 radio;

void setup() {
  Serial.begin(115200);
  Wire.begin();
  radio.setup(RESET_PIN, -1, CURRENT_MODE, SI473X_ANALOG_AUDIO, XOSCEN_CRYSTAL);
  radio.setFM(8400, 10800, 10390, 10);  // FM 87–108 MHz, start 103.9 MHz
  Serial.println("Si4732 FM ready");
}

void loop() {
  // Read current station info
  radio.getCurrentReceivedSignalQuality();
  uint8_t rssi = radio.getCurrentRSSI();
  Serial.print("RSSI: "); Serial.println(rssi);
  delay(1000);
}

RGB LED Strip (WS2812)

#include <FastLED.h>

#define LED_PIN  38
#define NUM_LEDS 8

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<WS2812B, LED_PIN, GRB>(leds, NUM_LEDS);
  FastLED.setBrightness(50);
}

void loop() {
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::Green;
  }
  FastLED.show();
  delay(500);
  FastLED.clear();
  FastLED.show();
  delay(500);
}

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LVGL

T-Embed Si4732 uses a 1.9-inch ST7789V TFT (320×170). LVGL 8.x works via TFT_eSPI in the official repository.

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

static lv_disp_draw_buf_t draw_buf;
static lv_color_t buf[320 * 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(1);
  lv_init();
  lv_disp_draw_buf_init(&draw_buf, buf, NULL, 320 * 10);

  static lv_disp_drv_t disp_drv;
  lv_disp_drv_init(&disp_drv);
  disp_drv.hor_res = 320;
  disp_drv.ver_res = 170;
  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-Embed Si4732");
  lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
}

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

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Peripheral Examples

Display (ST7789V)

#include <TFT_eSPI.h>

TFT_eSPI tft;

void setup() {
  tft.begin();
  tft.setRotation(1);
  tft.fillScreen(TFT_BLACK);
  tft.setTextColor(TFT_WHITE, TFT_BLACK);
  tft.setTextSize(2);
  tft.drawString("T-Embed Si4732", 40, 75);
}

void loop() {}

Si4732 DSP Radio (SI4735 library)

#include <SI4735.h>

SI4735 si4735;

void setup() {
  Serial.begin(115200);
  Wire.begin();
  // Reset pin varies by board — check utilities.h
  si4735.setup(RESET_PIN, FM_BAND_TYPE);
  si4735.setFM(8400, 10800, 10390, 10); // 88–108 MHz, start at 103.9 MHz, step 100 kHz
  Serial.println("Si4732 FM ready");
}

void loop() {
  si4735.getCurrentReceivedSignalQuality();
  Serial.print("RSSI: ");
  Serial.print(si4735.getCurrentRSSI());
  Serial.println(" dBuV");
  delay(1000);
}

RGB LED Strip (APA102)

#include <FastLED.h>

#define LED_CLK  14
#define LED_DATA 13
#define NUM_LEDS 8

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<APA102, LED_DATA, LED_CLK, BGR>(leds, NUM_LEDS);
  FastLED.setBrightness(50);
}

void loop() {
  for (int i = 0; i < NUM_LEDS; i++) leds[i] = CRGB::Green;
  FastLED.show();
  delay(500);
  FastLED.clear();
  FastLED.show();
  delay(500);
}

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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 bands does Si4732 support?
A: Si4732 supports AM (520–1710 kHz), FM (64–108 MHz), and shortwave/SSB bands, making it suitable for a wide range of radio receiver projects.