Building a Smart Dustbin Using Arduino Nano

In this detailed blog post, we will guide you through building a smart dustbin using an Arduino Nano, ultrasonic sensors, a gas sensor, an LCD, and a servo motor. This project combines various sensors and components to create an intelligent system that opens the lid when someone approaches, detects the fullness of the bin, and monitors the gas levels indicating rotting waste. Let's dive into the components, circuit diagram, code, and step-by-step instructions to build your smart dustbin.

Components Needed

• Arduino Nano
• Ultrasonic Sensors (HC-SR04) x 2
• Gas Sensor (MQ-135)
• 20x4 LCD
• Servo Motor (SG90 or similar)
• Breadboard and Jumper Wires
• Resistors (if needed for voltage dividers or pull-ups)
• Power Supply (Battery or USB)

Circuit Diagram

Connections

1. Arduino Nano to Ultrasonic Sensors:

   • Ultrasonic Sensor 1 (for presence detection):
     • VCC to 5V
     • GND to GND
     • TRIG to D2
     • ECHO to D3
   • Ultrasonic Sensor 2 (for level detection):
     • VCC to 5V
     • GND to GND
     • TRIG to D4
     • ECHO to D5

2. Gas Sensor (MQ-135):

   • VCC to 5V
   • GND to GND
   • A0 (analog output) to A0 on Arduino

3. 20x4 LCD:

   • RS to D8
   • E to D7
   • D4 to D6
   • D5 to D5
   • D6 to D4
   • D7 to D3

4. Servo Motor:

   • VCC to 5V
   • GND to GND
   • Signal to D9

Code

Here is the code to integrate all components and display information on the LCD while controlling the servo motor based on sensor readings.

 

Detailed Explanation

Ultrasonic Sensors

• Presence Detection: One ultrasonic sensor measures the distance to detect if a person is near the bin. If someone is detected within the threshold distance (20 cm), the servo motor will open the lid.
• Level Detection: Another ultrasonic sensor measures the distance to the trash level. If the distance is below the threshold (10 cm), the bin is considered full.

Gas Sensor (MQ-135)

• The MQ-135 gas sensor detects the level of rotting waste by measuring the concentration of gases emitted. The analog value from the sensor is read and displayed on the LCD.

20x4 LCD

• The LCD displays the current status of the dustbin, including the lid status, fullness, and gas level.

Servo Motor

• The servo motor opens and closes the dustbin lid based on the presence detection sensor reading.

Arduino Nano

• The Arduino Nano processes the sensor readings and controls the servo motor and LCD display.

Assembly Instructions

1. Connect all components according to the circuit diagram provided.
2. Upload the code to your Arduino Nano using the Arduino IDE.
3. Power the system using a suitable power supply (battery or USB).
4. Test the system by approaching the dustbin and adding/removing trash to observe the behavior.

Conclusion

Building a smart dustbin using an Arduino Nano, ultrasonic sensors, a gas sensor, a 20x4 LCD, and a servo motor is a practical project that integrates various sensors and components to create an intelligent waste management system. This project not only helps in understanding sensor integration and control but also provides a functional solution for maintaining cleanliness and hygiene. By following this guide, you can create your own smart dustbin and customize it further according to your requirements.

Happy building!