T-Watch 2021 get it now

Overview

LILYGO T-Watch 2021 is an open-source ESP32-based smart watch development platform. Powered by the ESP32 dual-core Xtensa LX6 @ 240 MHz with Wi-Fi and Bluetooth 4.2, it features a 1.54-inch ST7789V TFT touchscreen (240 × 240) with capacitive touch, an AXP202 PMU for battery management, a BMA423 accelerometer for step counting and gesture detection, an S76G GNSS module for GPS positioning, and a built-in microphone. The 380 mAh LiPo battery and USB-C charging make it a complete wearable development solution. Compatible with PlatformIO, Arduino, and the open-source TTGO_TWatch_Library.

Quick Start

Example Support

Example	PlatformIO/Arduino	ESP-IDF	Description
TTGO_TWatch_Library	✓		Watch UI, GPS, BLE, accelerometer examples

PlatformIO

1. Install Visual Studio Code and Python
2. Search for and install the PlatformIO IDE extension in VS Code
3. Open the TTGO_TWatch_Library project folder
4. Open platformio.ini, select the LILYGO_WATCH_2021 environment
5. Click ✓ to compile, connect via USB-C, click → to upload

Arduino

1. Install Arduino IDE
2. Install Arduino ESP32
3. Copy the TTGO_TWatch_Library folder to your Arduino libraries folder
4. In Tools → Board, configure:

Arduino IDE Setting	Value
Board	ESP32 Dev Module
CPU Frequency	240 MHz (WiFi)
Flash Size	4MB (32Mb)
Partition Scheme	Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
PSRAM	Enabled
Upload Speed	921600

5. Click Upload

Development Platforms

1. Arduino IDE
2. PlatformIO

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Key Features

• ESP32 dual-core Xtensa LX6 @ 240 MHz, Wi-Fi + Bluetooth 4.2
• 1.54-inch ST7789V TFT touchscreen (240 × 240) with FT6236 capacitive touch
• AXP202 PMU for power management and battery monitoring
• BMA423 3-axis accelerometer with step counter and gesture detection
• S76G GNSS module (GPS/GLONASS/BeiDou)
• Built-in PDM microphone
• 380 mAh LiPo battery with USB-C charging
• Vibration motor for haptic feedback
• 4 MB Flash, 8 MB PSRAM

Specifications

Parameter	Value
SOC	ESP32, Dual-core Xtensa LX6 @ 240 MHz
Flash	4 MB
PSRAM	8 MB
Wireless	Wi-Fi 802.11 b/g/n, Bluetooth 4.2
Display	1.54-inch ST7789V TFT, 240 × 240
Touch	FT6236 capacitive touch
PMU	AXP202
IMU	BMA423 (accelerometer + step counter)
GNSS	S76G (GPS/GLONASS/BeiDou)
Microphone	PDM MEMS microphone
Vibration	Vibration motor
Battery	380 mAh LiPo
USB	USB-C

Pin Diagram

Display (ST7789V)

Signal	GPIO
MOSI	19
SCLK	18
CS	5
DC	27
BL	12
RST	— (hardware)

I2C Bus (AXP202, BMA423, FT6236)

Signal	GPIO
SDA	21
SCL	22

GNSS (S76G, UART)

Signal	GPIO
TX	34
RX	33
PPS	37

Dimensions

Schematic

• T-Watch 2021 GitHub Repository (hardware)

Datasheet

• ESP32 Datasheet
• AXP202 Datasheet
• BMA423 Datasheet

Software Libraries

• TTGO_TWatch_Library GitHub Repository

Dependent Libraries

• TFT_eSPI
• XPowersLib
• LVGL

FAQ

• Q. How do I configure the watch in Arduino? A. In your sketch, include LilyGoWatch.h and define LILYGO_WATCH_2021 before the include. This configures pin assignments for the 2021 model automatically.

• Q. The touchscreen is not responding. What should I check? A. Confirm I2C address for FT6236 is 0x38. Check that SDA = GPIO21 and SCL = GPIO22. Ensure AXP202 powers the display backlight before touch initialization.

• Q. Can I replace the watch strap? A. Yes. The T-Watch uses a standard 20 mm watch strap. Any 20 mm quick-release strap is compatible.

Changelog

Version	Date	Notes
T-Watch 2020	—	Original design
T-Watch 2021	—	Revised with S76G GNSS, BMA423, improved PMU