WeMos D1 CH340 WiFi Arduino UNO R3-Compatible Development Board ESP8266 ESP-12F

$9.89

WeMos D1 R2 ESP8266 WiFi Board. 3.3V LOGIC -- do NOT apply 5V to any GPIO pin or it will be destroyed. Use a level shifter for 5V devices. WiFi is 2.4GHz ONLY.

Arduino UNO R3 form factor with built-in 802.11 b/g/n WiFi. Program with Arduino IDE using ESP8266 board package. CH340 USB-to-serial chip.

Key Specs:
• MCU: ESP8266 (80MHz, 4MB flash)
• GPIO: 11 digital + 1 analog (A0, 3.2V max)
• WiFi: 802.11 b/g/n, 2.4GHz
• Power: Micro USB 5V, DC jack 9-24V, or 5V pin
• USB Chip: CH340
• Size: 69x54mm (2.7x2.1in)

Safe pins for general use: D1, D2, D5, D6, D7. Pins D3, D4, D8 have boot restrictions. USB data cable required (not included -- charge-only cables won\'t work).

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Electronics for IoT, Prototyping & DIY

WeMos D1 R2 ESP8266 WiFi Board. 3.3V LOGIC -- do NOT apply 5V to any GPIO pin or it will be destroyed. Use a level shifter for 5V devices. WiFi is 2.4GHz ONLY.

Arduino UNO R3 form factor with built-in 802.11 b/g/n WiFi. Program with Arduino IDE using ESP8266 board package. CH340 USB-to-serial chip.

Safe pins for general use: D1, D2, D5, D6, D7. Pins D3, D4, D8 have boot restrictions. USB data cable required (not included -- charge-only cables won\'t work).

Ships from USA. Fast free US shipping, hassle-free returns, responsive support.

WeMos D1 R2 WiFi Development Board – ESP8266 ESP-12F – Arduino UNO R3 Form Factor – CH340 USB

The WeMos D1 R2 is a WiFi-enabled development board based on the ESP8266 ESP-12F module, built in the familiar Arduino UNO R3 form factor. It features built-in 802.11 b/g/n WiFi (2.4 GHz), 11 digital GPIO pins, 1 analog input, CH340 USB-to-serial programming, and flexible power options -- making it ideal for IoT projects, home automation, web servers, and wireless sensor networks.

⚠️ Important: This is a 3.3V logic level board. All GPIO pins operate at 3.3V. Applying 5V to any GPIO pin will permanently damage the ESP8266 chip. If connecting 5V sensors or modules, you must use a level shifter. The analog input (A0) has a maximum input voltage of 3.2V.⚡ Key Features

Built-In WiFi: ESP8266 ESP-12F module with 802.11 b/g/n WiFi (2.4 GHz)
Arduino UNO R3 Form Factor: Same board layout and header spacing -- compatible with many UNO shields (with voltage considerations)
Arduino IDE Compatible: Program using the familiar Arduino IDE with the ESP8266 board package
11 Digital GPIO Pins: All support interrupt, PWM, I²C, and one-wire (except D0)
1 Analog Input: 10-bit ADC on pin A0 (3.2V max input)
CH340 USB-to-Serial: Reliable USB programming and serial communication via Micro USB
Flexible Power Options: Power via Micro USB (5V), DC barrel jack (9–24V), or 5V pin
On-Board Voltage Regulation: 5V switching power supply (1A) plus 3.3V LDO
80 MHz Processor: ESP8266 running at 80 MHz with 4MB flash memory

📐 SpecificationsMicrocontrollerESP8266 (Tensilica L106 32-bit)WiFi ModuleESP-12F (802.11 b/g/n, 2.4 GHz)Clock Speed80 MHz (configurable to 160 MHz)Flash Memory4 MBSRAM64 KB instruction / 96 KB dataDigital I/O Pins11 (GPIO with interrupt/PWM/I²C/one-wire, except D0)Analog Input Pins1 (A0, 10-bit ADC, 3.2V max)Operating Voltage (Logic)3.3VUSB Power Input5V via Micro USBDC Jack Power Input9V – 24V DCOn-Board Regulator5V switching (1A) + 3.3V LDOUSB-to-Serial ChipCH340Upload Speed115200 baud (default)Board DimensionsApprox. 69 × 54 mm (2.7 x 2.1 inches) L × W📌 Pinout Quick ReferenceBoard PinESP8266 GPIOFunctionNotesD0GPIO16Digital I/ONo interrupt/PWM/I²C. Deep sleep wake.D1GPIO5Digital I/O, SCL✅ Safe for general useD2GPIO4Digital I/O, SDA✅ Safe for general useD3GPIO0Digital I/O⚠️ Must be HIGH at bootD4GPIO2Digital I/O, LED⚠️ Must be HIGH at boot. On-board LED.D5GPIO14Digital I/O, SCLK✅ Safe for general useD6GPIO12Digital I/O, MISO✅ Safe for general useD7GPIO13Digital I/O, MOSI✅ Safe for general useD8GPIO15Digital I/O, CS⚠️ Must be LOW at bootTXGPIO1UART TXUsed during uploadRXGPIO3UART RXUsed during uploadA0ADC0Analog Input10-bit ADC. Max 3.2V input.📦 What\'s in the Box

1× WeMos D1 R2 ESP8266 WiFi Development Board

USB cable is not included. A Micro USB data cable is required for programming and power (charge-only cables will not work).

🛒 What You\'ll Need

Micro USB Data Cable -- for programming and power (must be a data cable, not charge-only)
Arduino IDE -- free download from arduino.cc, with the ESP8266 board package installed
CH340 USB Driver -- usually included with Windows 10/11, macOS, and Linux; manual install if needed

🔌 Compatible With

Arduino IDE (with ESP8266 board package)
NodeMCU / Lua Arduino UNO shields (check 3.3V compatibility first)
Standard solderless breadboards (via header pins)

🎯 Typical Applications

IoT devices and smart home automation
WiFi-connected web servers and dashboards
Wireless sensor nodes (temperature, humidity, motion)
MQTT clients for Home Assistant, Node-RED, and other platforms
Remote data logging and monitoring
WiFi-controlled relays, LEDs, and actuators
Weather stations and environmental monitors
Prototyping and learning WiFi-enabled embedded systems

🚀 Quick Setup

Install the CH340 USB driver if your computer doesn\'t recognize the board when plugged in
Open the Arduino IDE, go to File > Preferences, and add the ESP8266 board manager to Tools > Board > Boards Manager, search for esp8266, and install the package
Select Tools > Board > \"LOLIN (WEMOS) D1 R2 & mini\"
Connect the board via Micro USB, select the correct COM port, and upload the Blink example

💡 Tip: The built-in LED on the WeMos D1 R2 is active LOW -- writing LOW turns it ON, and writing HIGH turns it OFF. This is the opposite of most Arduino boards. If your Blink sketch seems inverted, that\'s normal! Also, the ESP8266 only supports 2.4 GHz WiFi -- it cannot connect to 5 GHz networks.⚠️ Important Notes

3.3V Logic Level: All GPIO pins are 3.3V -- applying 5V to any pin will permanently damage the ESP8266 chip. Use a level shifter for 5V devices.
Analog Input Limit: Maximum input voltage on A0 is 3.2V -- exceeding this can damage the ADC
DC Jack Voltage: The DC barrel jack accepts 9V–24V -- do not exceed 24V
Boot Pin Restrictions: D3 (GPIO0), D4 (GPIO2), and D8 (GPIO15) have specific state requirements during boot -- connecting peripherals that pull these pins to the wrong state will prevent the board from starting
WiFi is 2.4 GHz Only: The ESP8266 does not support 5 GHz WiFi networks
Not 100% Arduino UNO Compatible: Despite the UNO form factor, pin mapping, voltage levels, and peripherals differ from a genuine Arduino UNO -- code and shields may need modifications
GPIO Current Limit: Each pin can source/sink approximately 12 mA (20 mA absolute max) -- use a transistor or MOSFET for higher-current loads

🏪 About Envistia Mall

Envistia Mall is a US-based electronics retailer specializing in development boards, sensors, modules, and components for makers, engineers, and educators. We ship from the United States with fast handling times. Product documentation and technical support are available at our dedicated support site.

📦 Fast Free US Shipping | 🔄 Hassle-Free Returns | 📧 Responsive Customer Support

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WeMos D1 CH340 WiFi Arduino UNO R3-Compatible Development Board ESP8266 ESP-12F

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