Wemos D1 mini
ESP8266 ESP8266. Small ESP8266 board with 4 MB of flash and a CH340 USB chip. Wi-Fi only, no Bluetooth.
2 projects
Specifications
Figures for Wemos / LOLIN D1 mini (v4, USB-C).
- Chip
- ESP8266EX
- Processor
- 1 core, Tensilica L106, 160 MHz
- RAM
- about 50 KB free with Wi-Fi
- Flash
- 4 MB
- Wi-Fi
- Wi-Fi 4, 2.4 GHz
- USB
- USB-C
- Logic level
- 3.3 V
- Size
- 25.4 × 34.3 mm
Sources
Checked against these documents on October 15, 2026.
Common problems
The board does not start after wiring D3, D4 or D8
These pins set the boot mode. At power on GPIO15 (D8) must be low, GPIO2 (D4) and GPIO0 (D3) high. Move the wire to another pin.
A 5 V sensor on a GPIO pin
The logic is 3.3 V, the datasheet limit for an input is 3.6 V. Use a level shifter for 5 V signals.
It does not wake up from deep sleep
Connect D0 (GPIO16) to RST: the timer wakes the chip through this wire.
Projects for this board
Tasmota for ESP8266
Local smart home firmware for ESP8266 boards: sensors, relays, rules and a web page, with MQTT and no cloud.No solderingAbout 15 min2 boardsJust the boardCan be built in an eveningWLED
Web page and phone control for WS2812B LED strips on an ESP8266: effects, palettes, presets and timers.SolderingAbout 30 min2 boardsBesides the board: WS2812B LED strip and 1 moreCan be built in an eveningGuides
Have a project for Wemos D1 mini? Publish it, and it shows up on this page.