Published May 18, 2019 © LGPL

ESP8266 to ESP8266 Direct Communication

This tutorial will help you to replace other transceiver modules for any other project that includes wireless communication.

IntermediateFull instructions provided1 hour57,415

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board

SparkFun Pushbutton switch 12mm

3 mm LED: Red

Resistor 1k ohm

Software apps and online services

Arduino IDE

Story

Working Video

This tutorial will help you to replace other transceiver modules for your any other project that includes wireless communication. We will use ESP8266-based boards, one in WiFi-STA mode and the other in WiFi-AP mode. NodeMCU V3 is my choice for this project, you may use any other ESP8266 board. To verify data transfer, I'm using buttons as input at one side and LEDs as output at other side, you can transmit any sensor data using this method.

Circuit

Server:

Its a very basic circuit, you need to attach 4 input buttons with one NodeMCU, use 1k resistor to pull-up pins D0, D1, D2 and D3, by pressing button, respective pin should be pull-down.

Client:

Attach 4 LEDs at D0, D1, D2 and D3 pins, respectively.

Check attached fritzing diagram.

Programming

Download attach sketches for server and client and upload in your nodeMCU/wemos or any other ESP8266 based board, LEDs are at client side and Buttons are at server side. I'm sending data in Json format, so you guys need to attach Json library in your Arduino IDE, this library will also help you to deal with multiple parameters in your other projects.

Your Attention Require

Hope this tutorial will help you in some way, kindly subscribe our youtube channel for more video tutorials.

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https://www.youtube.com/channel/UCCkp1sp1LCuMyQ9PP...

Code

//hammadiqbal12@gmail.com

#include <ESP8266WiFi.h>


#define btn0 16
#define btn1 5
#define btn2 4
#define btn3 0


const char *ssid = "ssid";
const char *password = "password";


int sensorValue0 = 0;       //sensor value, I'm usingg 0/1 button state
int sensorValue1 = 0;        
int sensorValue2 = 0;        
int sensorValue3 = 0;       

void setup() {
  Serial.begin(115200);
  delay(10);

  pinMode(btn0, INPUT);
  pinMode(btn1, INPUT);
  pinMode(btn2, INPUT);
  pinMode(btn3, INPUT);


  // set the ESP8266 to be a WiFi-client
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }

}

void loop() {
if(digitalRead(btn0) == LOW) sensorValue0 = 1;
if(digitalRead(btn1) == LOW) sensorValue1 = 1;
if(digitalRead(btn2) == LOW) sensorValue2 = 1;
if(digitalRead(btn3) == LOW) sensorValue3 = 1;

if(digitalRead(btn0) == HIGH) sensorValue0 = 0;
if(digitalRead(btn1) == HIGH) sensorValue1 = 0;
if(digitalRead(btn2) == HIGH) sensorValue2 = 0;
if(digitalRead(btn3) == HIGH) sensorValue3 = 0;


  // Use WiFiClient class to create TCP connections
  WiFiClient client;
  const char * host = "192.168.4.1";            //default IP address
  const int httpPort = 80;

  if (!client.connect(host, httpPort)) {
    Serial.println("connection failed");
    return;
  }

  // We now create a URI for the request. Something like /data/?sensor_reading=123
  String url = "/data/";
  url += "?sensor_reading=";
  url +=  "{\"sensor0_reading\":\"sensor0_value\",\"sensor1_reading\":\"sensor1_value\",\"sensor2_reading\":\"sensor2_value\",\"sensor3_reading\":\"sensor3_value\"}";

  url.replace("sensor0_value", String(sensorValue0));
  url.replace("sensor1_value", String(sensorValue1));
  url.replace("sensor2_value", String(sensorValue2));
  url.replace("sensor3_value", String(sensorValue3));


  // This will send the request to the server
  client.print(String("GET ") + url + " HTTP/1.1\r\n" +
               "Host: " + host + "\r\n" +
               "Connection: close\r\n\r\n");
  unsigned long timeout = millis();
  while (client.available() == 0) {
    if (millis() - timeout > 5000) {
      Serial.println(">>> Client Timeout !");
      client.stop();
      return;
    }
  }
}

//hammadiqbal12@gmail.com


#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <ArduinoJson.h>



#define led0 16               //D0
#define led1 5                //D1
#define led2 4                //D2
#define led3 0                //D3

DynamicJsonBuffer jsonBuffer;

const char *ssid      = "ssid";
const char *password  = "password";

int sensorValue0 = 0;        
int sensorValue1 = 0;        
int sensorValue2 = 0;        
int sensorValue3 = 0;        
String sensor_values;

ESP8266WebServer server(80);

void handleSentVar() {

  if (server.hasArg("sensor_reading"))
  {
    sensor_values = server.arg("sensor_reading");
    Serial.println(sensor_values);
  }
  JsonObject& root = jsonBuffer.parseObject(sensor_values);
//  if (!root.success()) {
//    Serial.println("parseObject() failed");
//    return;
//  }
//  if (root.success())
//  {
    sensorValue0          = root["sensor0_reading"].as<int>();
    sensorValue1          = root["sensor1_reading"].as<int>();
    sensorValue2          = root["sensor2_reading"].as<int>();
    sensorValue3          = root["sensor3_reading"].as<int>();

//  }

  Serial.println(sensorValue0);
  Serial.println(sensorValue1);
  Serial.println(sensorValue2);
  Serial.println(sensorValue3);

  toggle_leds();

  server.send(200, "text/html", "Data received");
}


void setup() {
  Serial.begin(9600);
  WiFi.softAP(ssid, password);
  IPAddress myIP = WiFi.softAPIP();

  pinMode(led0, OUTPUT);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  
  //toggle_leds();                 //turn off all leds as all the sensor values are zero
  
  server.on("/data/", HTTP_GET, handleSentVar); // when the server receives a request with /data/ in the string then run the handleSentVar function
  server.begin();
}

void loop() {
  server.handleClient();
}

void toggle_leds()
{
  if (sensorValue0 == 0)  digitalWrite(led0, LOW);
  if (sensorValue1 == 0)  digitalWrite(led1, LOW);
  if (sensorValue2 == 0)  digitalWrite(led2, LOW);
  if (sensorValue3 == 0)  digitalWrite(led3, LOW);

  if (sensorValue0 == 1)  digitalWrite(led0, HIGH);
  if (sensorValue1 == 1)  digitalWrite(led1, HIGH);
  if (sensorValue2 == 1)  digitalWrite(led2, HIGH);
  if (sensorValue3 == 1)  digitalWrite(led3, HIGH);
}

Credits

Hammad Iqbal

6 projects • 41 followers

I'm an Electrical Engineer and here I'm to share my knowledge about Embedded system.

ESP8266 to ESP8266 Direct Communication

Things used in this project

Hardware components

Software apps and online services

Story

Circuit

Programming

Your Attention Require

Schematics

Circuit Diagram

Code

Server

Client

Json Library

Credits

Hammad Iqbal

Comments

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ESP8266 to ESP8266 Direct Communication

ESP8266 to ESP8266 Direct Communication

Things used in this project

Hardware components

Software apps and online services

Story

Circuit

Programming

Your Attention Require

Schematics

Circuit Diagram

Code

Server

Client

Json Library

Credits

Hammad Iqbal

Comments

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