Serial Communication between NodeMCU and Arduino

Hello

today i will show you how to Serial Communication between NodeMCU and Arduino

First you have to know about 

What is Serial Communication

Serial communication is a communication process wherein data transfer occurs by transmitting data one bit at a time in sequential order over a computer bus or a communication channel. It is the most widely used approach to transfer information between data processing equipment and peripherals. Binary One represents a logic HIGH or 5 Volts, and zero represents a logic LOW or 0 Volts, used for communicating between the Arduino board and a computer or other devices. All Arduino boards have at least one serial port which is also known as a UART or USART. It communicates on digital pins 0 (RX) and 1 (TX) as well as with the computer via USB. Serial communication on pins TX/RX uses TTL logic levels (5V or 3.3V depending on the board).To establish serial communication between two devices, the devices should be connected as shown below.

 Serial Communication

Arduino to Nodemcu Connection

ARDUINO PART:

In Arduino, we shall consider pin 5 as Rx and pin 6 as Tx. To use the GPIO pins for serial communication SoftwareSerial library can be used. Here we have created a serial port named s with pin 5 as RX and pin 6 as TX.

// Arduino code
#include <SoftwareSerial.h>
SoftwareSerial s (5,6);
 
void setup () {
s.begin (9600);
}
 
void loop () {
int data = 50;
if (s.available ()> 0)
{
  s.write (data);
}
}

NODEMCU PART:

In NodeMCU we shall make pin 5 as Tx and pin 6 as Rx. So data sent by Arduino will be received by the NodeMCU and vice versa. So we can establish a successful Serial Communication between NodeMCU and Arduino.

#include <SoftwareSerial.h>

SoftwareSerial s (D6, D5);

int data;

void setup () {

s.begin (9600);

Serial.begin (9600);

}

 

void loop () {

   s.write ("s");

   if (s.available ()> 0)

   {

     data = s.read ();

     Serial.println (data);

   } 

}