Introger: Blocking Intruder [IoT Door Lock and Notice Board Using NodeMCU ESP8266]

By: Daniella Stefani and Lukas Sebastian - Computer Engineering - Binusian 2022 - Bina Nusantara University

Introger: Blocking Intruder is a device that allows you to lock your door from a distance and it's equipped with an LCD so you can notify people. Introger is basically an Intovert's Charger that helps you to tell other people when you want to be alone and lock them out, but this device can be used for a lot of things, like when you're already far away from home and you realize that you haven't locked your door.

For this device, the application used is Blynk which can be downloaded from Play Store and App Store. You just have to run the Blynk application and you can lock and unlock your door and input some text to be displayed on the LCD.

Software:

• Blynk
• Arduino IDE
• NodeMCU Board Manager
• Blynk Library
• LCD I2C Library

Hardware:

• 1 x Power Supply 5V 3.3V
• 1 x Breadboard
• 1 x NodeMCU ESP8266 Module
• 1 x LCD I2C
• 1 x 74HC14N
• 1 x Relay 5V
• 1 x Jack DC Female
• 1 x Solenoid Door Lock 12V
• 2 x 12V Adaptor
• Wires/Jumper

1. Download the Blynk App on Play Store/App Store:

   • Play Store: https://play.google.com/store/apps/details?id=cc....

   • App Store: https://apps.apple.com/us/app/blynk-control-arduin...

2. Create an account and log in to your account.
3. Create a new project, insert the project name, choose the device (NodeMCU), choose the connection type (WiFi), after that the authorization token will be sent to your email.
4. Click on the plus-circle button and add 1xButton Widget and 2xText Input.
5. Click the Button widget, change the output into D4, change the mode to switch, and change the ON/OFF LABELS into LOCK (for ON) and UNLOCK (for OFF).
6. Click the first Text Input widget, change the output into V0, change the hint into "Input First Line", and change the character limit to 16.

7. Click the second Text Input widget, change the output into V1, change the hint into "Input Second Line", and change the character limit to 16.

1. Install Arduino IDE and open the application.
2. Go to File => Preferences => Additional Board Manager URLs => Paste this link (http://arduino.esp8266.com/stable/package_esp8266com_index.json)
3. Go to Tools => Board => Board Manager => Search "ESP8266" => Install "esp8266" by ESP8266 Community.
4. Go to Sketch => Include Library => Manage Libraries => Search "Blynk" => Install "Blynk" by Volodymyr Shymanskyy => Search "Liquid Crystal I2C" => Install "LiquidCrystal I2C" by Frank de Brabander.
5. Type this code on Arduino IDE:

#define BLYNK_PRINT Serial
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <LiquidCrystal_I2C.h>
#include <Wire.h>

char auth[] = "yourAuthToken";
char ssid[] = "yourWifiName";
char pass[] = "yourWifiPass";

LiquidCrystal_I2C lcd(0x27,16,2);

void setup(){
   lcd.init();
   lcd.backlight();
   Serial.begin(9600);
   Blynk.begin(auth,ssid,pass);
}

BLYNK_WRITE(V0){
   lcd.clear();
   String textIn = param.asStr();
   Serial.print(textIn + "\n");
   lcd.setCursor(0,0);
   lcd.print(textIn);
}

BLYNK_WRITE(V1){
   String textIn = param.asStr();
   Serial.print(textIn + "\n");
   lcd.setCursor(0,1);
   lcd.print(textIn);
}

void loop(){
   Blynk.run();
}

This is the Circuit Diagram of Introger: Blocking Intruder.

1. Connect 5V and GND from Power Supply to a breadboard. This will give supply to the breadboard that will be used later.
2. Power Supply and NodeMCU ESP8266 Connection: connect 3.3V and GND to 3V and G.

3. LCD I2C and Power Supply Connection: connect VCC and GND to the + and - on the breadboard (5V Power Supply).

4. LCD I2C and NodeMCU ESP8266 Connection: connect SCL and SDA to D1 and D2, respectively.
5. 74HC14N and Power Supply Connection: connect pin 14 (VCC) and 7 (GND) to 5V and GND (or + and - on the breadboard).
6. 74HC14N and NodeMCU ESP8266 Connection: connect pin 1 (1A) to pin D4.
7. Relay and Power Supply Connection: connect VCC and GND to the + and - on the breadboard (5V Power Supply).
8. Relay and 74HC14N Connection: connect IN to pin 2 (1Y).
9. Jack DC Female, Solenoid Door Lock, Relay Connection: connect + jack DC to + Solenoid Door Lock (red wire), connect - Solenoid Door Lock (black wire) to NO relay, connect C relay to - jack DC.