LILYGO’s T-Watch Ultra is an ESP32-S3-based smartwatch development platform that appears to be an upgrade over the previous T-Watch-S3 Plus (1.3-inch display and a 940mAh battery), with a larger 2.01-inch AMOLED touch display, a higher-capacity 1,100mAh battery, and an IP65 waterproof and dustproof rating.
The device integrates a u-blox MIA-M10Q GNSS module for positioning, a SX1262 LoRa transceiver for long-range communication, and a Bosch BHI260AP smart sensor for motion-based AI applications. Additionally, it features an RTC chip, NFC, a built-in microphone, a haptic driver, a microSD card slot, and a USB Type-C port for programming and charging. The watch targets applications such as Meshtastic nodes, GPS tracking, wearable IoT interfaces, edge AI sensing, and custom smartwatch firmware development.
LILYGO T-Watch Ultra specifications:
SoC – Espressif ESP32-S3R8
CPU – Dual-core Tensilica LX7 microcontroller up to 240 MHz with vector instructions for AI acceleration
Memory – 512KB SRAM, 8MB PSRAM
Wireless – WiFi 4 and Bluetooth 5.0 LE + Mesh connectivity
Storage
16MB QSPI flash
MicroSD card slot
Display – 2.01-inch AMOLED display with 410 x 502 resolution, 16.7M colors, and capacitive touch (CST9217)
Audio – Built-in microphone, MAX98357A I2S Class-D amplifier
Wireless Connectivity
2.4 GHz WiFi 4 (802.11 b/g/n) and Bluetooth 5.0 LE (from ESP32-S3 itself)
GNSS – u-blox MIA-M10Q module
LoRa – Semtech SX1262 LoRa transceiver (868MHz, 915MHz, or 920MHz options available)
NFC – STMicroelectronics ST25R3916
USB – USB Type-C port for charging and programming
Sensors – Bosch BHI260AP AI smart sensor (IMU)
Misc
PCF85063A RTC (Real-Time Clock)
DRV2605 haptic driver motor (ERM and LRA)
Hardware Reset and Boot buttons
Power
1,100mAh (4.07 Wh) battery
AXP2101 highly integrated Power Management Unit (PMU)
Dimensions – 63.5 x 49 x 22 mm
Ingress Protection – IP65 (waterproof and dustproof)
ESP32-S3-powered IP65-rated LILYGO T-Watch Ultra Smartwatch pinout diagram
In terms of software support, the smartwatch works with the Arduino IDE, PlatformIO, the ESP-IDF framework, and MicroPython. LILYGO provides the LilyGoLib library on GitHub with example projects (including factory test code) and drivers for peripherals such as the AMOLED display, LoRa radio, GNSS, NFC, and sensors. The company clarifies that to program the board with Arduino IDE, you will need the Arduino-ESP32 core version 3.3.0-alpha1 or newer, and board settings must be configured for the correct radio variant (e.g., SX1262). Since PlatformIO does not yet fully support the newer ESP32 Arduino core, developers need to use the separate LilyGoLib-PlatformIO repository as a workaround.
The documentation on GitHub clearly states that if the USB device keeps connecting and disconnecting, which can occur after installing third-party firmware such as Meshtastic, you may need to manually put the device into download mode before uploading new firmware.
Meshtastic (beta) firmware on T-Watch Ultra
Previously, we have written about various other ESP32-based watch development platforms, including NASA Artemis Watch 2.0 (NASA-inspired wearable kit for education), Waveshare ESP32-S3 2.06-inch AMOLED touch, and watch-like penetration testing tools, like the Deauther Watch X and Deauther Watch V4S IR, but it’s harder to find a watch devkit with built-in LoRa connectivity.
The LILYGO T-Watch Ultra is available on AliExpress for around $95, with different LoRa bands including 433 MHz, 868 MHz, 915 MHz, 920 MHz, and 2.4 GHz (SX1280). It can also be purchased from the official LILYGO store for $78.32 with standard and express shipping options available, and we suspect it might eventually show up on the company’s Amazon store. Note that at the time of writing, only the 868 MHz, 915 MHz, and 920 MHz options are available on AliExpress or the LILYGO store.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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