Seon Rozenblum's TinyWATCH S3 Is an Espressif ESP32-S3-Powered DIY Smartwatch Platform
Released as open hardware with an open source firmware, the TinyWATCH S3 is hardware-complete but a firmware work-in-progress.
Seon Rozenblum, also known as the "Unexpected Maker," has launched a smartwatch kit powered by the Espressif ESP32-S3 microcontroller and featuring a 240×280 color touchscreen display: the TinyWATCH S3.
"TinyWATCH S3 [is] an open source hackable smart watch," Rozenblum explains of his creation. "Its main purpose is as hackable smart watch/wearable hardware product to be used for firmware development — either the official open source firmware lead by me, or your own firmware if you want to go down that path… or to be used just a dev board for code hacking and general projects."
The heart of the smartwatch, brought to our attention by CNX Software, is a custom board designed by Rozenblum and playing host to an Espressif ESP32-S3 system-on-chip, offering two 32-bit Tensilica Xtensa LX7 cores running at up to 240MHz, an ultra-low-power RISC-V coprocessor core, single-band Wi-Fi 4, and Bluetooth 5 Low Energy (BLE) with Bluetooth Mesh support. There's 512kB of on-board static RAM (SRAM), which Rozenblum has expanded with 2MB of pseudo-static RAM (PSRAM) accessible over a quad-SPI bus, and 8MB of quad-SPI flash storage.
The board sits behind an ST7789-based 240×280 color display with a capacitive touch layer, while also driving a range of peripherals: a real-time clock, as you might expect from a watch, a six-axis inertial measurement unit (IMU), separate magnetometer, MEMS microphone, magnetic buzzer, haptic vibration motor, and a battery fuel gauge, plus buttons for power, reset, and user control.
While the hardware is in its second revision, Rozenblum admits the firmware is still very much a work-in-progress. "Though TinyWATCH can be worn as a watch," he warns, "even as your daily driver (battery required), its firmware is early alpha, and not close to a 'consumer watch' level that you might expect if you were to buy a 'finished product.'"
For those who aren't put off by such warnings, the TinyWATCH S3 is now available to order on the Unexpected Maker Shop for $59; no battery nor watch strap is included, though a 3D-printed case is supplied. Hardware design files and firmware source code files are spread across four repositories on GitHub, under the CERN Open Hardware License v1.2 and the GNU General Public License 3.0 respectively.