Wemos has announced the launch of the LOLIN S3 Mini, pin-compatible with the popular LOLIN D1 Mini but based on the Espressif ESP32-S3 — giving it accelerated vector processing for on-device tinyML workloads.
The new development board, brought to our attention by CNX Software, is the latest entry in Wemos' LOLIN Mini range, following the LOLIN C3 Mini — a device launched last year as a pin-compatible alternative to the popular LOLIN D1 Mini, based on a RISC-V processor core. Late last year the company also launched the LOLIN C3 Pico, a more compact take on the design — but this new board is a return to the Mini form factor.
The LOLIN S3 Mini is built around the Espressif ESP32-S3FH4R2 chip, which is a step back in time compared to the ESP32-C3 variant the company launched last year. The part dates from before Espressif announced its intention to move completely over to the free and open-source RISC-V architecture for all its future chips, and instead offers two Tensilica Xtensa LX7 processor cores running at up to 240MHz and with vector instruction extensions for accelerated machine learning processing.
Elsewhere in the chip is 512kB of static RAM (PSRAM), with an additional 2MB of pseudo-static RAM (PSRAM) on the board alongside 4MB of quad-SPI flash storage. There's a radio with 2.4GHz Wi-Fi 4 and Bluetooth 5.0 Low Energy (BLE) connectivity with Bluetooth Mesh support, too, linked to a PCB antenna opposite the board's USB Type-C data and power connector.
The board brings out the ESP32-S3's general-purpose input/output (GPIO) pins to two 16-pin headers — keeping it pin-compatible with other LOLIN Mini models, but making breadboard use awkward — with 27 general-purpose pins, analog input and output capabilities, and I2C, SPI, UART, and USB On-The-Go (OTG) buses. There's also a single user-addressable RGB LED on the board, alongside an input button.
More information on the LOLIN S3 Mini is available on the Wemos wiki, while variants shipping with MicroPython pre-loaded — and support for the Arduino IDE and ESP-IDF, should you choose — are now available to order from the Wemos AliExpress store at $5.