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2.2 Hardware description of Node MCU

The NodeMCU ESP8266 development board comes with the ESP-12E module containing the ESP8266 chip having Tensilica Xtensa 32-bit LX106 RISC microprocessor. NodeMCU has 128 KB RAM and 4MB of Flash memory to store data and programs. NodeMCU can be powered using a Micro USB jack and VIN(external supply).

PIN CONFIGURATION:

Pin Category

Name

Description

Power

Micro-USB, 3.3V, GND, Vin

Micro-USB: NodeMCU can be powered through the USB port

3.3V: 3.3V is used to supply the components which require 3.3V like bluetooth etc.

GND: Ground pins

Vin: External Power Supply

Control Pins

EN, RST

The pin and the button resets the microcontroller.Reset button deso not delete the code it starts the code from the beginning.

Analog Pin

A0

Used to measure analog voltage in the range of 0-3.3V and connect analog sensors.

GPIO Pins

GPIO1 to GPIO16

NodeMCU has 16 general purpose input-output pins on its board

UART PinsTXD0, RXD0, TXD2, RXD2NodeMCU has two UART interfaces, UART0 (RXD0 & TXD0) and UART1 (RXD1 & TXD1). UART1 is used to upload the firmware/program.