Lolin S3 Mini – Tiny $5 ESP32-S3 board follows Wemos D1 Mini form factor

LOLIN S3 Mini is a tiny ESP32-S3 WiFi and Bluetooth IoT development board that follows the Wemos D1 Mini form factor and supports its equally tiny stackable shields to add relays, displays, sensors, and so on.

Wemos/LOLIN introduced their first ESP32-S3 board last year with the LOLIN S3 board with plenty of I/Os and an affordable $7 price tag.  But I prefer the company’s Mini form factor because of its size and the ability to select add-on boards to easily add a range of features to your projects. So I’m pleased to find out the company has now launched the LOLIN S3 Mini following the ESP32-C3 powered LOLIN C3 Mini board unveiled in March 2022.


LOLIN S3 Mini specifications:

  • WiSoC – Espressif Systems ESP32-S3FH4R2
    • CPU – dual-core Tensilica LX7 @ up to 240 MHz with vector instructions for AI acceleration
    • Memory – 512KB RAM, 2MB PSRAM
    • Storage – 4MB QSPI flash
    • Connectivity – 2.4 GHz WiFi 4 and Bluetooth 5.0 LE with support for long-range, up to 2Mbps data rate, mesh networking
  • Antenna- PCB antenna
  • USB – USB Type-C port for power and programming
  • Expansions – 2x 16-pin headers with up to 27x GPIOs, ADC, DAC, I2C, SPI, UART, USB OTG, etc…
  • Misc – 1x RGB LED (IO47), Reset button, user-programmable button (IO0)
  • Power Supply – 5V via USB Type-C port
  • Dimensions – 34.3 x 25.4mm
  • Weight – 3 grams
LOLIN S3 Mini pinout diagram
LOLIN S3 Mini pinout diagram

The board comes pre-installed with MicroPython, but can also be programmed with Arduino and the ESP-IDF. You’ll find tutorials to get started with either MicroPython or Arduino in the Wiki along with the PDF schematics and dimensions file.

The sensor shields available for Wemos D1 Mini and compatible boards, like the S3 Mini featured in this post, could make it especially interesting for TinyML applications. Note the shiels/add-on boards only use the 8-pin headers on each side of the boards, and not the other two inner rows which could be used for another purpose.

Wemos D1 Mini stackable shields
Wemos D1 Mini with DHT22 temperature sensor and relay shields (for reference only since it could get pretty hot between the relay and ESP board)

LOLIN is selling the S3 Mini board for $5 plus shipping, and the D1 Mini shields range from 60 cents (button shield) to $6.90 (SGP30 TVOC air quality shield).

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Marius Motea
1 year ago

First version of LOLIN C3 Mini was with issues.. but they still sell the boards. I buy two, both did not work and got overheated, then notice github issues with lot of complaints, some claiming that removing one capacitor mai fix the issue, but for me and others this did not work. Hope these boards are working fine. One think i notice is that LOLIN fix was to replace the antenna with a ceramic one. This has a PCB antenna so be carefully.

1 year ago

I borrowed a driver circuit from (see my comment)and designed a hat for this board with three 5v output pins. They could drive LED strips, I guess.

Christopher de Vidal

BTW you can’t breadboard this configuration. Should be obvious to most but wasn’t obvious to me as a newbie.

1 year ago

In fact you can if you only set one row per side (the outer one), and the pinout makes this perfectly functional, just with limited I/O. I remember seeing a photo where the inner connectors were soldered towards the top so that they could be connected with Dupont wire.

Khadas VIM4 SBC