LilyGo T-Embed

An ESP32-S3 development board designed for embedded applications, offering various interfaces and expansion options.

USB-C Native USB
LilyGo T-Embed board
95.4 × 36.4 mm
ESP32-S3
MCU
240MHz
clock
16MB
flash
512KB
SRAM
7· 2 ADC
GPIO
BLE 5.0+ WiFi
radio
On this page

Pinout

11 pins
View:
LilyGo T-Embed pinout diagram
PinGPIOLabelsStatusCapabilitiesNotes
144IO44U0RXDRXstrappingi2c · uartGrove IIC/UART connector data line (U0RXD); use as I2C or UART RX
243IO43U0TXDTXstrappingi2c · uartGrove IIC/UART connector data line (U0TXD); use as I2C or UART TX
3-3V3power-3.3V output on the Grove IIC/UART connector
4-GNDground-Ground on the Grove IIC/UART connector
516SDAIO16safeadc · i2c2x4 IDC GPIO header, secondary (bit-banged) I2C SDA
617SCLIO17safeadc · i2c2x4 IDC GPIO header, secondary (bit-banged) I2C SCL
740IO40strappingspi2x4 IDC GPIO header; shared with onboard microSD (SPI SCK)
838IO38safespi2x4 IDC GPIO header; shared with onboard microSD (SPI MISO)
941IO41strappingspi2x4 IDC GPIO header; shared with onboard microSD (SPI MOSI)
10-3V3power-3.3V output on the 2x4 IDC GPIO header
11-GNDground-Ground on the 2x4 IDC GPIO header

Start with these

3 pins with no boot or system involvement
SDAIO16SCLIO17IO38

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

sampled at boot or shared with debug/serial
PinLabelWhat to knowRole
IO44U0RXD (GPIO44)Used for bootloader input (download mode via serial). If repurposed, you cannot use the default UART0 download mode for programming the chip.Other
IO43U0TXD (GPIO43)Used for bootloader output and UART console logs. If repurposed, you will lose the default serial output (and programming via UART0).Other
IO40MTDO (GPIO40)Default JTAG TDO output for debugging. Using it as GPIO will interfere with JTAG debugging functionality.Other
IO41MTDI (GPIO41)Default JTAG TDI input for debugging. Should be reserved for JTAG or left unused if JTAG is to remain available.Other
These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.
Pinout notes Across 11 pins, the LilyGo T-Embed exposes 7 GPIO plus 3V3 and GND for power. Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO16 and SCL on…

Across 11 pins, the LilyGo T-Embed exposes 7 GPIO plus 3V3 and GND for power.

Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO16 and SCL on GPIO17, while TX/RX on GPIO43 and GPIO44 cover serial logging and flashing.

Beyond plain digital I/O you get 2 ADC-capable pins for sensors and battery monitoring.

4 of the exposed pins carry boot-time or system duties on the ESP32-S3 (IO44, IO43, IO40 and 1 more) - check the guidance above before wiring anything to them. SDA, SCL and IO38 are free of any such role - the safest first picks.

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Native USB - shows up as a port right away, no driver needed. Not detected? Hold BOOT while plugging in.
2
Match & flash
Set the Tools options shown, then click Upload.
3
Verify it runs
GPIO16 toggles - wire an LED and resistor to it, or change the pin to your board's own LED.
Set these in Tools · leave everything else at default
Arduino IDE 2.x - Tools Copy
Board: "ESP32S3 Dev Module"
USB CDC On Boot: "Enabled"
Flash Size: "16MB (128Mb)"
Flash Mode: "DIO"
PSRAM: "OPI PSRAM"
Partition Scheme: "16M Flash (3MB APP/9.9MB FATFS)" (default)
Upload Speed: "921600"
▸ every other Tools option - leave at default
Board: ESP32S3 Dev Module
USB CDC On Boot: Enabled
Flash Size: 16MB (128Mb)
Flash Mode: DIO
PSRAM: OPI PSRAM
Partition Scheme: 16M Flash (3MB APP/9.9MB FATFS)
Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32S3 Dev Module
blink.ino Copy
// toggle GPIO16 - wire an LED and resistor to it
void setup() {
  pinMode(16, OUTPUT);
}
void loop() {
  digitalWrite(16, HIGH); delay(500);
  digitalWrite(16, LOW);  delay(500);
}
board to selectesp32-s3-devkitc-1⧉ copy
platformio.ini Copy
[env:lilygo_t_embed]
platform = espressif32
board = esp32-s3-devkitc-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_opi
build_flags = -DBOARD_HAS_PSRAM
Find it: PlatformIO Home ▸ Boards, search esp32-s3-devkitc-1 - or type it after board =.
board to selectesp32-s3-devkitc-1⧉ copy
device.yaml Copy
esp32:
  board: esp32-s3-devkitc-1
  variant: esp32s3
  framework:
    type: esp-idf
psram:
  mode: octal
  speed: 80MHz

# blink - GPIO16
output:
  - platform: gpio
    pin: 16
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
Find it: search ESPHome's board list for esp32-s3-devkitc-1 (same ids as PlatformIO).
esptool doesn't pick board settings - a prebuilt .bin already has them baked in. This is just the raw flash command.
terminal Copy
esptool.py --chip esp32s3 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x0 firmware.bin
--port = your /dev/tty* (macOS/Linux) or COMx (Windows).
Build details: sketch space 3145728 B · data 327680 B · DIO

Specifications

ESP32-S3 · 95.4 × 36.4 mm · vs other ESP32 chips →
Compute
MCU
ESP32-S3
Clock
240 MHz
SRAM · Flash
512 KB · 16MB · 8MB (OPI) PSRAM
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
5.0 LE
Antenna
PCB
I/O
GPIO · ADC
7 · 2
UART · I²C · SPI
3 · 2 · 2
PWM
8 channels
Power
USB
USB-C
Serial
Native (CDC)
Boot address
0x0
Display
Screen
LCD · 1.9" · 170x320
Driver
ST7789
Touch
No
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · QIO
Sketch · Data
3 MB · 320 KB
36.4 mm95.4 mm
95.4 × 36.4 mm
The LilyGo T-Embed uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with QIO boot mode. The maximum sketch size is 3 MB with 320 KB available for data.

About this board

Inside sits the ESP32-S3 - a dual-core Xtensa with vector extensions suited to AI workloads.

The $28.56 price tag is typical for an ESP32-S3 board.

Only 7 GPIO are broken out, where most ESP32-S3 boards manage about 22 - worth checking the pinout covers what you need.

Around the module: 8MB (OPI) PSRAM, an LCD 1.9" 170x320 display, a microSD slot, a microphone (Dual MEMS), a speaker (1W 8Ω), an amplifier (MAX98357A), an addressable RGB LED, a rotary encoder, battery charging via JST 1.25mm and Reset/Boot buttons.

It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S3 boards.


The LilyGo T-Embed is an ESP32-S3-based development board designed for versatile embedded applications. With an integrated 1.9-inch IPS LCD (non-touch) and a rotary encoder, it is perfect for UI-based projects.

Featuring WiFi 802.11 b/g/n and Bluetooth 5 (LE), the T-Embed allows seamless wireless connectivity for IoT and automation applications.

Equipped with 8MB PSRAM and 16MB Flash, it is capable of handling complex processing tasks efficiently.

Where to buy

prices are typical street prices
LilyGo T-Embed
LilyGo T-Embed
$28.56per unit, typical

Resources

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