# LILYGO T-Watch S3 > Open-source ESP32-S3 smartwatch with LoRa, 1.3" 240×240 IPS touchscreen, haptic feedback, accelerometer, speaker, microphone, IR transmitter, and 1500mAh battery. Supports Meshtastic, ESPHome, Arduino, and MicroPython. ## Quick Facts - **Brand:** LILYGO - **Board Type:** smartwatch - **Price:** ~$42.98 - **Product Readiness:** consumer - **CPU:** Xtensa LX7 dual-core @ 240MHz, vector AI, hardware crypto - **CPU Architecture:** Xtensa LX7 - **CPU Cores:** 2 - **RAM:** 512KB SRAM - **PSRAM:** 8MB QSPI - **Flash:** 16MB - **USB:** Micro-USB - **Power:** 5V + LiPo - **Operating Voltage:** 3.3V - **Battery:** 1500mAh - **Charging Port:** Micro-USB - **Antenna:** U.FL/IPEX (LoRa) + PCB built-in (WiFi) - **Display:** 1.3" IPS LCD 240×240 ## Connectivity - **Wifi:** 802.11 b/g/n - **Bluetooth:** BLE 5.0 - **Lora:** SX1262 433/868/915MHz ## Open Source - **Status:** partially-open - **Firmware:** Yes - **Schematics:** Yes - **PCB Layout:** No ## Compatible Firmware arduino, micropython, esphome, meshtastic, platformio ## Use Cases - smart-watch - fitness-tracker - lora-mesh-networking - off-grid-communication - voice-assistant - remote-control ## Components - **ESP32-S3FN16R8** (mcu): Espressif ESP32-S3FN16R8 dual-core Xtensa LX7 @ 240MHz with 16MB flash, 8MB PSRAM, WiFi 802.11 b/g/n, BLE 5.0, USB OTG, vector AI instructions, and hardware crypto (AES-XTS, RSA, SHA). — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fen%2Fproducts%2Fsocs%2Fesp32-s3&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **SX1262** (radio): Semtech SX1262 LoRa transceiver supporting 150–960MHz (433/868/915MHz variants) with +22 dBm output power, -148 dBm sensitivity, and ultra-low 4.2mA receive current. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.semtech.com%2Fproducts%2Fwireless-rf%2Flora-connect%2Fsx1262&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **AXP2101** (power-management): X-Powers AXP2101 highly integrated PMIC managing LiPo battery charging (up to 1024mA programmable), multiple DC-DC converters, and LDO rails powering the ESP32-S3, display, LoRa, haptic driver, and RTC backup. — [Datasheet](https://openhardware.directory/r?to=http%3A%2F%2Fwww.x-powers.com%2Fen.php%2FInfo%2Fproduct_detail%2Farticle_id%2F95&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **BMA423** (accelerometer): Bosch BMA423 3-axis accelerometer with hardware step counting, activity recognition (walk/run/still), wrist-tilt detection, tap detection for display wake, and I2C interface at ultra-low power. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.mouser.com%2Fdatasheet%2F2%2F783%2FBSCH_S_A0010021471_1-2525113.pdf&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **DRV2605** (haptic): Texas Instruments DRV2605 I2C haptic driver supporting both ERM and LRA vibration motors with 100+ licensed Immersion TouchSense effects and smart-loop auto-resonance tracking. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.ti.com%2Fproduct%2FDRV2605&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **SPM1423HM4H-B** (microphone): Knowles SPM1423HM4H-B PDM MEMS microphone with high SNR, low current consumption, and digital PDM output for voice capture, audio recording, and voice assistant applications. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fmedia.digikey.com%2Fpdf%2FData%2520Sheets%2FKnowles%2520Acoustics%2520PDFs%2FSPM1423HM4H-B.pdf&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **MAX98357A** (audio-amplifier): Analog Devices MAX98357A I2S Class-D mono amplifier delivering 3.2W into 4Ω with no external MCLK required, enabling audio output directly from the ESP32-S3's I2S peripheral. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.analog.com%2Fen%2Fproducts%2Fmax98357a.html&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **ST7789V3** (display-driver): Sitronix ST7789V3 TFT LCD controller driving the 1.3-inch 240×240 IPS panel via SPI at 262K colors, 450 cd/m² brightness, and 800:1 contrast ratio. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.newhavendisplay.com%2Fappnotes%2Fdatasheets%2FLCDs%2FST7789V3.pdf&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **FT6336U** (touch-controller): FocalTech FT6336U single-channel capacitive touch controller with I2C interface, swipe and tap gesture recognition, and interrupt-driven wake — connected on a dedicated I2C bus (Wire1). — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fbuydisplay.com%2Fdownload%2Fic%2FFT6236-FT6336-FT6436L-FT6436_Datasheet.pdf&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **PCF8563** (rtc): NXP PCF8563 nano-power I2C real-time clock with integrated 32.768 kHz crystal, alarm function, and battery backup via AXP2101 VBACKUP rail for accurate timekeeping across power cycles. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.nxp.com%2Fproducts%2FPCF8563&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - **IR12-21C** (ir-transmitter): Everlight IR12-21C 940nm surface-mount infrared LED transmitter driven by GPIO2 for sending IR remote control signals to TVs, air conditioners, and other IR-controlled home appliances. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.everlight-led.cn%2Fzh%2Fdatasheet-download%2Fitem%2Fir12-21c-tr8-datasheet&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) ## Protocols - **I2C** (Wire0): SDA: GPIO10, SCL: GPIO11 - **I2C** (Wire1 (Touch)): SDA: GPIO39, SCL: GPIO40 - **SPI** (LoRa): SCK: GPIO3, MISO: GPIO4, MOSI: GPIO1, CS: GPIO5 - **SPI** (Display): SCK: GPIO18, MOSI: GPIO13, CS: GPIO12, DC: GPIO38 - **I2S** (Speaker): BCLK: GPIO48, WCLK: GPIO15, DOUT: GPIO46 - **PDM** (Microphone): SCK: GPIO44, DATA: GPIO47 ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | GPIO1 | LoRa MOSI | SPI | digital-input, digital-output | | GPIO2 | IR Transmitter | RMT | digital-output, pwm | | GPIO3 | LoRa SCK | SPI | digital-input, digital-output | | GPIO4 | LoRa MISO | SPI | digital-input, digital-output | | GPIO5 | LoRa CS | SPI | digital-input, digital-output | | GPIO7 | LoRa BUSY | SPI | digital-input | | GPIO8 | LoRa RESET | SPI | digital-output | | GPIO9 | LoRa IRQ | SPI | digital-input | | GPIO10 | I2C SDA | I2C | digital-input, digital-output | | GPIO11 | I2C SCL | I2C | digital-output | | GPIO12 | Display CS | SPI | digital-output | | GPIO13 | Display MOSI | SPI | digital-output | | GPIO14 | BMA423 INT | I2C | digital-input | | GPIO15 | I2S WCLK (Speaker) | I2S | digital-output | | GPIO16 | Touch INT | I2C | digital-input | | GPIO17 | RTC INT | I2C | digital-input | | GPIO18 | Display SCK | SPI | digital-output | | GPIO21 | AXP2101 INT | I2C | digital-input | | GPIO38 | Display DC | SPI | digital-output | | GPIO39 | Touch SDA (Wire1) | I2C | digital-input, digital-output | | GPIO40 | Touch SCL (Wire1) | I2C | digital-output | | GPIO44 | PDM SCK (Microphone) | PDM | digital-output | | GPIO45 | Display Backlight | PWM | digital-output, pwm | | GPIO46 | I2S DOUT (Speaker) | I2S | digital-output | | GPIO47 | PDM DATA (Microphone) | PDM | digital-input | | GPIO48 | I2S BCLK (Speaker) | I2S | digital-output | ## Description ## Overview The LILYGO T-Watch S3 is an open-source programmable smartwatch built around the ESP32-S3 dual-core Xtensa LX7 processor running at 240MHz. It combines a 1.3-inch 240×240 IPS touchscreen, LoRa radio (SX1262), WiFi 802.11 b/g/n, and Bluetooth 5.0 LE into a wearable form factor — giving makers and developers full control over their smartwatch firmware with 16MB flash and 8MB PSRAM to work with. The hardware is unusually rich for a watch-format device: a BMA423 3-axis accelerometer with hardware step counting and wrist-tilt detection, a DRV2605 haptic driver for 100+ programmable vibration effects, an AXP2101 power management IC for fine-grained battery control, a PDM MEMS microphone, a MAX98357A 3.2W Class-D audio amplifier, a PCF8563 real-time clock, and an infrared LED transmitter for controlling home appliances — all powered by a 1500mAh LiPo battery with Micro-USB charging. The T-Watch S3 is officially supported by Meshtastic for off-grid LoRa mesh communication, and has active community support for ESPHome (including voice assistant integration), MicroPython, and Arduino IDE. Both the firmware source and circuit schematics are publicly available on GitHub, making it a strong platform for custom smartwatch OS development, fitness tracking applications, home automation wearables, and long-range IoT field devices. The device is available in multiple LoRa frequency variants — 433MHz, 868MHz, and 915MHz (SX1262) — plus a 2.4GHz LoRa variant (SX1280), and alternative radio options including CC1101, LR1121, and SI4432. ## Where to Buy - [LILYGO Official](https://openhardware.directory/r?to=https%3A%2F%2Flilygo.cc%2Fproducts%2Ft-watch-s3&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) — $42.98 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Flilygo.cc%2Fproducts%2Ft-watch-s3&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FXinyuan-LilyGO%2FLilyGoLib&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fwiki.lilygo.cc&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) - [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FXinyuan-LilyGO%2FLilyGoLib%2Fblob%2Fmaster%2Fschematic%2FT_WATCH-S3%252025-03-24.pdf&ref=openhardware.directory&product=lilygo-t-watch-s3&source=md-export) ## Tags `esp32-s3`, `smartwatch`, `lora`, `meshtastic`, `esphome`, `wearable`, `iot`, `lilygo` ## Images ![LILYGO T-Watch S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-watch-s3/ec2f9962b98d.jpg) ![LILYGO T-Watch S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-watch-s3/4dbcead8f2d7.jpg) ![LILYGO T-Watch S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-watch-s3/a0f7ad4b7b04.jpg) ![LILYGO T-Watch S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-watch-s3/4800883ac316.png) ![LILYGO T-Watch S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-watch-s3/a1abd8d34b5b.jpg) ![LILYGO T-Watch S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-watch-s3/77c07c9b090d.jpg) ![LILYGO T-Watch S3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/lilygo-t-watch-s3/aa15f39401df.png) > **Battery Powered:** Li-Po --- [View full device page](https://openhardware.directory/devices/lilygo-t-watch-s3)