Wemos D1 Mini (ESP8266)

Wemos D1 Mini (ESP8266)

The Wemos D1 Mini is the de facto standard board for Tasmota and ESPHome-based home automation projects. Its compact size, low cost (~$3), breadboard-friendly layout, and extensive shield ecosystem make it the most widely used ESP8266 board in the DIY smart home community.

Key Features

• ESP8266EX SoC running at 80/160MHz with WiFi 802.11 b/g/n
• 4MB flash (enough for Tasmota with all features)
• 11 digital I/O pins, 1 analog input (A0, 3.3V max)
• Micro-USB for power and programming (CH340G USB-serial)
• 3.3V and 5V power pins for sensors
• Deep sleep support via D0-RST jumper

Shield Ecosystem

One of the D1 Mini's greatest strengths is its stackable shield system:

• Relay Shield — 5V 1A relay for switching mains loads
• DHT Shield — DHT11/DHT22 temperature and humidity
• OLED Shield — 0.66" SSD1306 64x48 I2C display
• WS2812B RGB Shield — addressable LED ring
• Motor Shield — dual DC motor or single stepper
• Battery Shield — LiPo charging and boost converter
• ProtoBoard Shield — custom circuit prototyping
• SD Card Shield — microSD via SPI
• Buzzer Shield — piezo buzzer
• Button Shield — momentary tactile switch

Tasmota Compatibility

The D1 Mini is one of the best-supported boards in Tasmota:

• Works with all standard Tasmota binaries (tasmota.bin, tasmota-sensors.bin, tasmota-display.bin, tasmota-ir.bin)
• Module type: Generic (18) with full GPIO mapping
• Flash via USB with Tasmotizer, esptool.py, or ESP Flasher
• All 11 GPIOs freely assignable to Tasmota functions

Common Tasmota Projects

• Temperature/humidity monitoring (DHT22, BME280, DS18B20)
• Motion sensor nodes (AM312, HC-SR501 PIR)
• Air quality sensors (PMS5003, MH-Z19B CO2)
• Smart LED controllers (WS2812B, PWM dimming)
• IR remote control hubs (IR TX/RX)
• Power monitoring (PZEM-004T)
• Motorized blinds controller
• MQTT sensor bridges

Pin Mapping

Pin	GPIO	Function	Notes
D0	GPIO16	Wake	No PWM/I2C, connect to RST for deep sleep
D1	GPIO5	SCL	Default I2C clock
D2	GPIO4	SDA	Default I2C data
D3	GPIO0	FLASH	Pull-up, boot mode select
D4	GPIO2	LED	Built-in LED (inverted), pull-up
D5	GPIO14	SCLK	SPI clock
D6	GPIO12	MISO	SPI data in
D7	GPIO13	MOSI	SPI data out
D8	GPIO15	CS	SPI chip select, pull-down
A0	ADC0	Analog	0–3.3V input
TX	GPIO1	TX	Serial transmit
RX	GPIO3	RX	Serial receive