LOLIN S3 mini

Board
by LOLIN (WEMOS)lolin-s3-mini≈ cheap (under ~$15)
Verify my boardCompareEdit on GitHub
Flash this board — 2 firmware options · Known good
LOLIN S3 mini pinout
Pinout

Specifications

Radiosinherited from ESP32-S3

Wi-Fi
Wi-Fi 4 · 2.4 GHz
Bluetooth LE
BLE 5
Bluetooth Classic
no
802.15.4
no

USB

Native USB
yes
Bridge chip
none — SoC native USB

Board

Form factor
lolin-mini
Dimensions
34.3 × 25.4 mm

Display & extras

Extras
rgb-led
Built onLOLIN S3 mini BoardESP32-S3 SoC

Thumb-sized bare-S3 board: ESP32-S3FH4R2 (4 MB flash, 2 MB PSRAM), native USB OTG, onboard RGB LED on IO47, 27 IO.

Firmware for this board

Known good

  • WLEDKnown goodhomeweb flasher
    Flash WLEDweb flasherknown-good

    Known good esp-atlas asserts this board↔firmware link at the shown trust tier — it does not guarantee your specific unit or the current firmware version. Flashing can erase keys/config and can brick the device. At your own risk.

Unverified

  • NerdMiner v2Unverifieddisplay
    Flash NerdMiner v2guided

    Unverified esp-atlas asserts this board↔firmware link at the shown trust tier — it does not guarantee your specific unit or the current firmware version. Flashing can erase keys/config and can brick the device. At your own risk.

Notes

  • Based on ESP32-S3FH4R2; 4 MB flash, 2 MB PSRAM
  • 27x digital I/O pins
  • Onboard addressable RGB LED on IO47
  • Native ESP32-S3 USB OTG; physical connector shape not stated on the official page (omitted)
  • Weight: 3 g
  • io.gpio_exposed=27 QUOTED: vendor page states "27x IO" (Features) and "Digital I/O Pins | 27" (Technical specs table); no enumerated GPIO pin-list/table is published in the spec table, so power_out is omitted
  • io.gpio_free=23 DERIVED: the vendor's own labeled pinout diagram (s3_mini_v1.0.0 silkscreen photo) enumerates exactly 27 header GPIO pads (1-18, 21, 33-38, 43, 44) -- matching the "27x IO" spec exactly; GPIO47 (the onboard RGB LED) is not among them, confirming it is off-header and needs no separate subtraction. Of esp32-s3's soc.reserved_pins, strapping GPIO3 is exposed (1 pin; 0/45/46 are not on the header); usb_flash_tied 35/36/37 are exposed (3 pins; 19/20 are not, consumed internally by native USB) -- so 27 - 1 - 3 = 23
  • usb_serial derived from usb.bridge (native) + soc usb.type otg-full-speed + serial-jtag

Verify my board

Reads the connected chip over USB and checks it against what esp-atlas cites for LOLIN S3 mini — over Web Serial, no backend, nothing leaves your browser.

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Serial monitor

Not connected.