What is ESP8266 NodeMCU & Specs

What is NodeMCU?

What is ESP8266 NodeMCU? How is it different from Arduino Board? – NodeMCU is a 32-bit microcontroller module with 4MB Flash and built-in WiFi that can be programmed using the Arduino IDE.

This NodeMCU is based on the ESP8266-12E wifi module based on the ESP8266EX microcontroller. ESP8266-12 is a module made by the company Espressif.

Before we look at the NodeMCU, let’s take a look at the pinout of the ESP8266-12E which is the base module of the NodeMCU V3.

What is ESP8266 NodeMCU & Specs
ESP8266-12E PinOut (this image property randomnerdtutorials.com)

If we look at the ESP8266-12E module above, it’s just a microcontroller module without USB to TTL, reset button, regulator, and filter.

So to be able to program this module, we have to add an extra circuit in order to use it.

To make it easier to operate and program this module, a module was made with an additional circuit, like the USB to TTL, reset button, regulator, and filter. And this module is called NodeMCU and shows this:

What is ESP8266 NodeMCU?

Because it has a built-in Bluetooth feature, NodeMCU is suitable for use with IOT projects such as Smart homes (automation), Wireless Industrial controllers, IP cameras, Sensor networks, Wi-Fi Network Electronic Devices, etc.

NodeMCU ESP8266EX Specs

The specifications of the esp8266ex CHIP used on the NodeMCU V3 board are as follows:


  • CPU Tensilica L106 32-bit processor
  • Flash 4MB
  • 160 MHz speed
  • Operating Voltage 2.5 V ~ 3.6 V (3.3V recommendation)
  • The average operating current is 80 mA
  • Operating temperature from -40 ° C- 125 ° C


  • 802.11 b / g / n protocol (HT20)
  • Frequency 2400 MHz ~ 2483.5 MHz (2.4 GHz ~ 2.5 GHz)
  • TX 802.11 b: +20 dBm, 802.11 g: +17 dBm, 802.11 n: +14 dBm
  • Sensitivity RX 802.11 b: –91 dbm (11 Mbps), 802.11 g: –75 dbm (54 Mbps), 802.11 n: –72 dbm (MCS7)

Pin Description

  • GPIO0 to GPIO16
    GPIO (General Purpose Input Output), NodeMCU has a digital 17pin that can be used as input and output. Each pin can be set an internal resistor for the pull-up and pull-down states.
  • ADC0
    ESP8266 on NodeMCU V3 only has 1 pin for analog. The precision of this ADC is 10-bit.
    This pin is used for SPI communication
  • TXD0, RXD0, TXD1 and RXD1
    This NodeMCU microcontroller module has two UART communication lines, which are named UART0 and UART1. For UART speeds, it is capable of up to 4.5Mbps (115200 x 40)
  • SCL and SDA
    The ESP8266 also supports I2C communication
  • PWM
    The ESP-12E used in the MCU V3 module has 4 PWMs, including pins D2, D5, D6 and D8.

For USB to TTL Converters, there are two types of IC used, the CP2102 and CH340. On the NodeMCU board, there is a flash button, which will be used later if we want to program the microcontroller. Next, we will learn How To Install NodeMCU In Arduino Ide.

I hope this article is useful.

1 thought on “What is ESP8266 NodeMCU & Specs”

  1. Pingback: CH340 dev ttyUSB not showing Linux, but detected in terminal - CHIPPIKO

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