NodeMCU ESP8266 microcontroller overview

The NodeMCU ESP8266 is a microcontroller with an integrated Wifi module. Very easy to use, it’s lightweight and has a memory and calculation capacity superior to that of the Arduino. Ideal for your connected projects.

Microcontroller features

The NodeMCU ESP8266 microcontroller uses the Tensilica 32-bit RISC CPU Xtensa LX106 microprocessor. This processor operates at a clock frequency of 80 MHz. It has 64 kB RAM, NC kB EEPROM and 4000 kB Flash memory (for programming and data logging).

CPU Tensilica 32-bit RISC CPU Xtensa LX106 Voltage : 3.3V Flash : 4000 kB RAM : 64 kB EEPROM : NC kB Clock speed : 80MHz WiFi : Yes Bluetooth : No SD : No

The microcontroller has a Wifi chip that enables it to connect to the local network, create a server or set up its own network so that other devices can connect to it.

Power supply

The NodeMCU ESP8266 microcontroller operates over a voltage range of 7-12V, thanks to its on-board voltage regulator, while the microprocessor operates with a voltage of 3.3V. In normal operation, the microcontroller consumes up to 45mA (if no power is supplied) and can accept a maximum current of 40mA on each of its IO pins.

Pinout

• Analog I/O : 1 (A0)
• Digital I/O : 5 (D0, D1, D3, D4, D7)
• PWM pins: 4 (D2, D5, D6, D8)
• Communication Serial: 10 (D0, D1, D2, D3, D4, D5, D12, D13, D14, D15)
• I2C communication : 1 ((‘D1’, ‘D2’))
• SPI communication: 1 ((‘D8’, ‘D5’, ‘D6’, ‘D7’))
• I2S communication: 1 ((‘D15’, ‘D2’, ‘D3’))
• Interrupt: 6 (D1, D2, D5, D6, D7, D8)

Basic code and pin identification

const int analogPin = A0;
const int digitalInPin = D1; // broches D1, D2, D5, D6,D7
const int digitalOutPin = D2; // D1 à D7
const int pwmPin = D4; // broches D1 à D8

int analogVal = 0;
int digitalState = LOW;
int pwmVal = 250;

void setup() {
  Serial.begin(115200);

  pinMode(analogPin, INPUT); // Argument OUTPUT, INPUT
  pinMode(digitalInPin, INPUT);
  pinMode(digitalOutPin, OUTPUT);
}

void loop() {
  analogVal = analogRead(analogPin); //  return int
  digitalState = digitalRead(digitalInPin); //  return boolean
  digitalWrite(digitalOutPin, HIGH); // valeur LOW(0) ou HIGH(1)
  analogWrite(pwmPin, pwmVal);// valeur 0-1023
}

For more information on pinout usage, please visit the ESP8266 Pinout Reference page.

Summary of features

How to get started