The NodeMCU ESP8266 (CP2102) is a WiFi-enabled development board that combines Arduino-like programming with built-in wireless connectivity. Based on the ESP-12E module, it’s ideal for IoT projects needing WiFi without complex wiring.
Core Specifications
Microcontroller: ESP-12E (ESP8266EX)
CPU: 32-bit Tensilica L106
Operating Voltage: 3.3V
Clock Speed: 80MHz (160MHz overclockable)
Flash Memory: 4MB
SRAM: 64KB + 32KB (cache)
Wireless: 802.11 b/g/n WiFi (2.4GHz)
I/O & Connectivity
Digital I/O Pins: 11 (GPIOs)
PWM Support: All digital pins (software)
Interrupts: All pins support interrupts
Analog Input: 1x 10-bit ADC (max 3.3V)
Communication:
UART: 1x hardware + 1x software
I2C & SPI: Software-configurable
Special Pins:
GPIO16: Deep sleep wakeup
USB & Power
USB-to-Serial: CP2102 chip (stable drivers)
Input Voltage: 5V via Micro-USB or Vin (4.5–10V)
Operating Current: ~70mA (WiFi active)
Deep Sleep Current: ~20μA
Physical Details
Dimensions: 49mm × 25mm
Weight: ~7g
Headers: Female (breadboard-friendly)
Key Advantages
✔ Integrated USB (CP2102): No external FTDI needed
✔ Lua & Arduino IDE Support: Flexible programming
✔ 4MB Flash: Stores large scripts/OTA updates
✔ Breadboard-Ready: Female headers for easy prototyping
Performance & Memory
80MHz CPU (faster than 8-bit Arduinos)
4MB Flash for firmware/web pages (vs. Uno’s 32KB)
64KB SRAM for network operations
Connectivity & Expansion
Stable CP2102 USB-Serial: Reliable uploads
Multiplexed GPIOs: (Check pinout – some restrict boot modes)
ADC Pin: Read sensors/battery voltage (0–3.3V range)
Power Efficiency
Deep Sleep (20μA): Ideal for battery projects
Onboard 3.3V Regulator: Powers sensors directly
Applications
WiFi Sensors (MQTT/HTTP to cloud)
Smart Plugs/Lights (Tasmota/ESPHome)
IoT Prototyping (Replace Uno + WiFi shield)
Why Choose NodeMCU?
Beginner-Friendly: Pre-soldered headers & USB
Community Support: Extensive Lua/Arduino libraries
Balanced Size: Easier to prototype than Wemos
Note: GPIO0/2/15 have boot mode restrictions – check pinout!
Package Includes: 1 x ESP8266 NodeMCU CP2102 Board