Let's explore NodeMCU ESP8266 Pin Description. ESP8266 is an 32-bit wifi enabled microcontroller chip. There are total 30 Physical Pins in which 13-Digital GPIO Port Pins and 1-Analog Pin (A0). Also there are 7-Power Pins in which three 3.3V Pins and Four GND Pins. Also we'll explore pinout of ESP8266 including it's UART, I2C, SPI and other protocol related pins on microcontroller.