# Wemos D1 Mini (ESP8266)

> Compact ESP8266-based WiFi development board with 4MB flash, 11 digital I/O pins, micro-USB, and a rich shield ecosystem. The most popular board for Tasmota and ESPHome DIY home automation projects.

## Quick Facts

- **Brand:** Wemos
- **Board Type:** dev-board
- **Price:** ~$3.5
- **Product Readiness:** developer
- **CPU:** ESP8266EX
- **CPU Architecture:** Xtensa LX106
- **CPU Cores:** 1
- **RAM:** 80KB SRAM
- **Flash:** 4MB
- **USB:** Micro-USB
- **Power:** Micro-USB 5V
- **Operating Voltage:** 3.3V
- **Antenna:** built-in PCB antenna

## Connectivity

- **Wifi:** 802.11 b/g/n
- **Bluetooth:** none

## Open Source

- **Firmware:** No
- **Schematics:** Yes
- **PCB Layout:** No

## Compatible Firmware

tasmota, esphome, arduino, micropython, NodeMCU

## Use Cases

- home-automation
- iot-sensor-node
- mqtt-bridge
- smart-lighting
- environmental-monitoring
- prototyping

## Components

- **ESP8266EX** (Microcontroller): Single-core Xtensa LX106 microcontroller with integrated WiFi 802.11 b/g/n, 80/160MHz clock, 80KB SRAM — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2F0a-esp8266ex_datasheet_en.pdf&ref=openhardware.directory&product=wemos-d1-mini-esp8266&source=md-export)
- **CH340G** (USB-Serial): USB to serial UART interface chip for programming and debugging via micro-USB connection — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.wch-ic.com%2Fdownloads%2FCH340DS1_PDF.html&ref=openhardware.directory&product=wemos-d1-mini-esp8266&source=md-export)

## Protocols

- **WiFi 802.11 b/g/n**
- **I2C**
- **SPI**
- **UART**
- **1-Wire**

## Description

# 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 |

## Where to Buy

- [Buy for $3.5](https://openhardware.directory/r?to=https%3A%2F%2Fwww.aliexpress.com%2Fitem%2F32529101036.html&ref=openhardware.directory&product=wemos-d1-mini-esp8266&source=md-export)

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.wemos.cc%2Fen%2Flatest%2Fd1%2Fd1_mini.html&ref=openhardware.directory&product=wemos-d1-mini-esp8266&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Ftasmota.github.io%2Fdocs%2FPeripherals%2F&ref=openhardware.directory&product=wemos-d1-mini-esp8266&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fwemos%2FD1_mini_Examples&ref=openhardware.directory&product=wemos-d1-mini-esp8266&source=md-export)

## Tags

`esp8266`, `wifi`, `tasmota`, `esphome`, `home-automation`, `iot`, `development-board`, `arduino`, `micropython`, `mqtt`

## Images

![Wemos D1 Mini (ESP8266)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/wemos-d1-mini-esp8266/35e8f871af8d.png)

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