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Pankaj Rai
Published © MIT

Controlling Relay with IR Sensor Using NodeMCU

Relay can be controlled if any object comes in front of IR sensor via NodeMCU. Extension of this project can be done using an IR remote.

BeginnerFull instructions provided1 hour3,605
Controlling Relay with IR Sensor Using NodeMCU

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board
NodeMCU ESP8266 Breakout Board
×1
IR Transceiver (Generic)
×1
High-Power Relay Shield for Particle Photon I²C 1-Channel SPDT 10-Amp
ControlEverything.com High-Power Relay Shield for Particle Photon I²C 1-Channel SPDT 10-Amp
×1
5 mm LED: Red
5 mm LED: Red
×1
Jumper wires (generic)
Jumper wires (generic)
×1

Software apps and online services

Arduino IDE
Arduino IDE
thingsai.io

Story

Read more

Schematics

schematics for relay control using IR SENSOR using NodeMCU

whenever something comes in front of ir sensor, relay will get on or off.

Code

senseIR2.ino

Arduino
#include <SoftwareSerial.h>
SoftwareSerial mySerial(12, 13); // RX, TX

#include <ESP8266WiFi.h>          //https://github.com/esp8266/Arduino
#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include "WiFiManager.h"          //https://github.com/tzapu/WiFiManager
#include <WiFiClientSecure.h>

int count=0,i,m,j,k;
int t ;   //,t1,t2,t3;
const int ProxSensor=A0;
int LED = 13;
int relay= 16;

//////////////////////////////////////// ALL DECLARATIONS for CLOUD //////////////////////////////
const char* host = "api.thingsai.io";                                 // OR host = devapi2.thethingscloud.com
const char* post_url = "/devices/deviceData";       // OR /api/v2/thingscloud2/_table/data_ac
const char* time_server = "baas.thethingscloud.com";             //this is to convert timestamp
const int httpPort = 80;
const int httpsPort = 443;
const char*  server = "api.thingsai.io";  // Server URL

char timestamp[10];

WiFiClient client;


/////////////////////////////////////////////////////////////////////////////////////////////////////////
void configModeCallback (WiFiManager *myWiFiManager) 
{
  Serial.println("Entered config mode");             //*-*-*-*-*-*-*-*-*-*-*-*-*-*if control enters this function then net is not connected
  Serial.println(WiFi.softAPIP());                  // "WiFi.softAPIP() is for AP" , "WiFi.localIP() is for STA",
                                                                
  Serial.println(myWiFiManager->getConfigPortalSSID());             //if you used auto generated SSID, print it
}
/////////////////////////////////////// TIMESTAMP CALCULATION function///////////////////////////////////////
int GiveMeTimestamp()
{
  unsigned long timeout = millis();

  while (client.available() == 0)
  {
    if (millis() - timeout > 50000)
    {
      client.stop();
      return 0;
    }
  }

while (client.available())
      {
        String line = client.readStringUntil('\r');                    //indexOf() is a funtion to search for smthng , it returns -1 if not found
        int pos = line.indexOf("\"timestamp\"");                       //search for "\"timestamp\"" from beginning of response got and copy all data after that , it'll be your timestamp
        if (pos >= 0)                                                     
        {
          int j = 0;
          for(j=0;j<10;j++)
          {
            timestamp[j] = line[pos + 12 + j];
          }
        }
      }
}  
////////////////////////////////////////////////////////////////////////////////////////////////////////

void setup() 
{ 
  pinMode(LED, OUTPUT);          // Pin 13 has an LED connected on nodeMCU board:  
  pinMode(relay, OUTPUT);   // pin 16 has a relay connected to node mcu board, defining that pin as output
  pinMode(ProxSensor,INPUT);    //Pin 2 is connected to the output of proximity sensor
  
  Serial.begin(115200);     //(19200,SERIAL_8E1) - data size = 8 bits , parity = Even , stop bit =  1bit
  mySerial.begin(115200);
  WiFiManager wifiManager;
 
  wifiManager.setAPCallback(configModeCallback);
                                                                                                    
  if(!wifiManager.autoConnect("iPankaj","80518051"))                   //wifiManager.autoConnect("AP-NAME", "AP-PASSWORD"); (OR) wifiManager.autoConnect("AP-NAME"); only ID no password (OR) wifiManager.autoConnect(); this will generate a ID by itself
  {
    Serial.println("failed to connect and hit timeout");     //control comes here after long time of creating Access point "NodeMCU" by NodeMCU and still it has not connected
    //reset and try again, or maybe put it to deep sleep
    ESP.reset();
    delay(1000);
  } 

  //if you come here you have connected to the WiFi
  Serial.println("connected...yeey :");
 
}

void loop() 
{
  long  analogValue = analogRead(ProxSensor);
{
 
  
/////////////////////////////////////// SEND THE QUERY AND RECEIVE THE RESPONSE///////////////////////  

   if(analogValue >= 500)      //Check the sensor output
  {
    t=1;                // to indicate on server that object is detected
    digitalWrite(13, HIGH);   // set the LED on when an object is placed in front of sensor   //analog output from sensor >500
    digitalWrite(16, HIGH);   // switch on the relay
    Serial.println(analogValue);
    delay(50);
  }
  else
  {
    t=0;             // to indicate on server that object NOT detected
    digitalWrite(13, LOW);    // set the LED off when no object is placed //analog output from sensor will be <500
    digitalWrite(16, LOW);    // turn off the relay
    Serial.println(analogValue);
    delay(50);
  }


       

          

  Serial.print("connecting to ");
  Serial.println(host);                          //defined upside :- host = devapi2.thethingscloud.com or 139.59.26.117

///////////////////////////////////// TIMESTAMP CODE SNIPPET /////////////////////////
Serial.println("inside get timestamp\n");
  if (!client.connect(time_server, httpPort)) 
  {
    return;                                                        //*-*-*-*-*-*-*-*-*-*
  }

  client.println("GET /api/timestamp HTTP/1.1");                            //Whats this part doing, i didnt get
  client.println("Host: baas.thethingscloud.com");
  client.println("Cache-Control: no-cache");
  client.println("Postman-Token: ea3c18c6-09ba-d049-ccf3-369a22a284b8");
  client.println();

GiveMeTimestamp();                        //it'll call the function which will get the timestamp response from the server
Serial.println("timestamp receieved");
Serial.println(timestamp);
///////////////////////////////////////////////////////////////////////////////

  Serial.println("inside ThingsCloudPost");

 
  String PostValue = "{\"device_id\":  61121695866, \"slave_id\": 2";
         PostValue = PostValue + ",\"dts\":" +timestamp;
   PostValue = PostValue +",\"data\":{\"obst\":" + t +"}"+"}";
  
  
  Serial.println(PostValue);

/* create an instance of WiFiClientSecure */
    WiFiClientSecure client;
    
    Serial.println("Connect to server via port 443");
    if (!client.connect(server, 443)){
        Serial.println("Connection failed!");
    } else {
        Serial.println("Connected to server!");
        /* create HTTP request */

        client.println("POST /devices/deviceData HTTP/1.1");
        client.println("Host: api.thingsai.io");
        //client.println("Connection: close");
        client.println("Content-Type: application/json");
        client.println("cache-control: no-cache");
        client.println("Authorization: Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.IjVhMzBkZDFkN2QwYjNhNGQzODkwYzQ4OSI.kaY6OMj5cYlWNqC2PNTkXs9PKy6_m9tdW5AG7ajfVlY");
        client.print("Content-Length: ");
        client.println(PostValue.length());
        client.println();
        client.println(PostValue);
//////////////////////////////////POSTING the data on to the cloud is done and now get the response form cloud server//////////////////
 Serial.print("Waiting for response ");
        while (!client.available()){
            delay(50); //
            Serial.print(".");
        }  
        /* if data is available then receive and print to Terminal */
        while (client.available()) {
            char c = client.read();
            Serial.write(c);
        }

        /* if the server disconnected, stop the client */
        if (!client.connected()) {
            Serial.println();
            Serial.println("Server disconnected");
            client.stop();
        }
    }
Serial.println("//////////////////////    THE END     /////////////////////");
delay(3000);
}
}

Credits

Pankaj Rai
10 projects • 33 followers
B.Tech (Electronics and communication Engineering), Enthusiastic about IOT , Robotics and Automation technologies. (Mb. - 9872647369)

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