ESP8266 In this project, we will use NodeMCU ESP8266 to build an IoT-based smart kitchen with automation and monitoring. One of the most important rooms in a house is the kitchen. The safety factor is the main aspect that must be taken into account during the activity in the kitchen. Gas leaks, fires that are out of control, high temperatures, and a damp environment must be found quickly and fixed. Aside from this, it's important to be able to monitor and control things like the lights, fridge, oven, and other kitchen appliances from afar. The main goal of this project is to use the Internet of Things to make a prototype of an IoT-based smart kitchen. The system uses multiple sensors, relays & NodeMCU ESP8266 Board. We can monitor all the sensor data on Blynk Applications. We can also send commands to kitchen appliances from the Blynk app.

ESP8266, NodeMCU DHT11 Sensor MQ-135 Sensor HC-SR501 Sensor, Passive Infrared (PIR) Sensor OLED Display Buzzer 5V, Active Piezo Buzzer Relay 4 Channel Relay Board Jumper Wires, Male/Female Jumper Wires Breadboard, 830 Points Breadboard 1USB Cable, Micro-USB Data Cable

Use the DHT11 sensor and the Blynk app to keep an eye on the kitchen's temperature and humidity.

Using the MQ-135 Gas Sensor on the Blynk app, you can check the Air Quality Index (Gas). The 0.96-inch OLED display shows the temperature, humidity, and gas level in the kitchen. When the gas level gets too high, the alarm goes off and the exhaust fan turns on. Detects the presence or absence of a person in the Kitchen using a PIR sensor Sends Alarm Staus, Exhaust Fan Status & Person in Room Status to Blynk App The Blynk app lets users turn on and off their fridge, oven, and room lights from a distance. System Design & Circuit Diagram We will utilize the sensors like DHT11 Humidity Temperature Sensor, MQ- 135 Gas Sensor, Passive Infrared Sensor to monitor the Indoor Air Quality Parameters. Similarly, a simple 5V buzzer can work as an alarming system. A relay is connected to an automatic exhaust fan. When the gas level goes over the threshold value, the relay turns on automatically.

Since we are using a 4-channel relay, the other 3 relays can be connected to kitchen appliances like a mixer, refrigerator, oven, water heater, induction, etc. A simple 0.96-inch I2C OLED can show the temperature, humidity, and gas level in the room in real time. Wemos D1 Mini Board or NodeMCU ESP8266 Board are the brains and hearts of this project. You can use any board that is based on the ESP8266-12E. The ESP8266 chip connects to the WiFi network and makes a connection with the Blynk application.

Use the diagram below as a guide and put the circuit together on a breadboard. Connect the SDA and SCL pins of the OLED display to the Wemos D2 and D1 pins. In the same way, connect the output pins of the DHT11, MQ-135, and PIR sensors to the Wemos D4, A0, and D3 pins. For the alarm system, you can connect the 5V active Buzzer to the D0 Pin of Wemos. We can use a 4 channel Relay Module to control the appliances in our homes. So using the jumper wires, connect the 4 channel relay input pin to the D5, D6, D7 & D8 of Wemos.

Now we need to set up the Blynk application so that we can get the data from the ESP8266. The Blynk Application used here is for IoT Based Smart Kitchen using NodeMCU ESP8266. Blynk is an application that runs over Android and IOS devices to monitor any IoT based application using Smartphones. It lets you make your own graphical user interface for an Internet of Things app. Here, we'll show the temperature, humidity, and air quality of the room and be able to control the kitchen appliances. So get the Blynk app from the Google Play Store and install it. The App Store has downloads for people who use IOS. Once the app is installed, open it and sign up using your email address and password. Make a new project from the dashboard and choose NodeMCU Board & Wifi Connection. Then, drag and drop or add from the widget list three buttons, two style buttons, and three gauges. Assign the three variables and give them names like temperature, humidity, and Air Quality Index Value as per the code.

In the same way, give the button's 3 variables and the styled button's 2 variables. You will get a letter in the mail with the code. Copy this authentication code. This is what your code will need. Testing of IoT Smart Kitchen Project After uploading the code, the Wemos D1 Board tries connecting to the WiFi network using the given SSID & Password. At the same time, you can also open the Serial Monitor. The Serial Monitor will show the Humidity, Temperature, Air Quality Index, Alarm Status, Human Presence, etc. The OLED Display, on the other hand, will show the Kitchen's temperature, humidity, and gas level. Once it connects to the WiFi network, it will start sending data to the Blynk app.

The Temperature, Humidity, and Air Quality Index data will be sent to the Blynk application, which will then show them on the Gauge. It will also

show whether the alarm is ON or OFF as well as the presence of humans inside the room or not. When the gas level reaches a certain value, the relay that controls the exhaust fan turns on by itself. The value of the threshold is set to 150 PPM. You can set it to any desired value. You can use the Blynk app to send the command to turn on the fridge, oven, and lights in the kitchen.