Automatic Trash Bin
The Automatic Trash Bin project demonstrates how robotics can simplify everyday tasks, integrating innovative technology into real-life applications. This system utilizes a 100 RPM BDC Motor with Encoder alongside an Ultrasonic Distance Sensor Module to automate the opening and closing of a trash bin lid. By detecting the presence of a hand or a nearby object, the ultrasonic sensor sends a signal to the motor, which precisely controls the lid’s movement.
About Tools and Materials:
SMD USB Gateway (Purchase Here)
Arduino Gateway Module (Purchase Here)
Ultrasonic Distance Sensor Module (Purchase Here)
Step 1: Hardware & Software Overview
Project Key Components
The SMD acts as a bridge between the script and the modules. It is responsible for interpreting the commands sent by the script and translating them into actions that read input from the Ultrasonic Distance Sensor Module and actuate the DC motor precisely.
The 100 RPM BDC Motor with Encoder is the actuator of the system. It moves the trash bin lid up.
Ultrasonic Distance Sensor Module
The Ultrasonic Distance Sensor Module is used to detect the approaching person or the hand.
The SMD library is at the heart of the application. It communicates with the SMD using a specific communication protocol, sending commands to read the Ultrasonic Distance Sensor Module and actuate the BDC motor.
Project Key Features
Hands-free Operation
The Ultrasonic Distance Sensor Module makes it easy in terms of hygiene and automation, automatic trash bin lid project makes life easier.
Adjustable Sensitivity
The script include parameters that can be edited by the user to change the sensivity of the system, it helps to avoid unwanted activations of the BDC motor.
Step 2: Assemble
Hardware Setup
Connect the SMD to the PC or Arduino board using USB Gateway Module or Arduino Gateway Module.
Connect the 100 RPM BDC Motor with Encoder to the motor ports of the SMD and the Ultrasonic Distance Sensor Module to the SMD using an RJ-45 cable.
Make sure that the SMD is powered and all connections are correct.
Project Wiring Diagram

Step 3: Run & Test
Run the Script
Execute the script, initiating the Automatic Trash Bin application.
Approach the trash bin, and observe how the lid opens automatically when the user is in close proximity.
Enhance and Customize
Fine-tune the sensitivity parameters in the script based on the user feedback and the specific requirements of the environment.
Explore additional features, such as automatic lid closing after a specified period or incorporating status indicators.
Codes
from serial.tools.list_ports import comports
from platform import system
import time
from smd.red import *
baudrate = 115200 # Baud rate of communication
ID = 0 # ID of the SMD
distance_id = 1 # ID of the ultrasonic distance sensor module
def USB_Port():
"""
Scans and identifies a compatible USB port for the current operating system.
Returns:
str: The detected USB port or None if no suitable port is found.
"""
# Get a list of available ports
ports = list(comports())
# Known USB port names for different operating systems
usb_names = {
"Windows": ["USB Serial Port"], # Names specific to Windows
"Linux": ["/dev/ttyUSB"], # Names specific to Linux
"Darwin": [ # Names specific to macOS
"/dev/tty.usbserial",
"/dev/tty.usbmodem",
"/dev/tty.SLAB_USBtoUART",
"/dev/tty.wchusbserial",
"/dev/cu.usbserial",
]
}
# Detect the operating system
os_name = system()
print(f"Operating System: {os_name}")
if ports:
for port in ports:
# Check if the port matches any known USB names
if any(name in port.device or name in port.description for name in usb_names.get(os_name, [])):
print(f"USB device detected on port: {port.device}")
return port.device # Return the first matching port
# If no suitable port is found, print the list of available ports
print("No suitable USB device found. Available ports:")
for port in ports:
print(f"Port: {port.device}, Description: {port.description}, HWID: {port.hwid}")
else:
print("No ports detected!")
return None
try:
# Find a valid serial port
SerialPort = USB_Port()
if not SerialPort:
raise Exception("No compatible USB port found. Please check your connection.")
print(f"Using serial port: {SerialPort}")
# Initialize the SMD module
master = Master(SerialPort, baudrate) # Defines the USB gateway module
master.attach(Red(ID)) # Gives access to the SMD of specified ID
# Motor and control configuration
master.set_shaft_rpm(ID, 100) # Sets the RPM value of the motor
master.set_shaft_cpr(ID, 6533) # Sets the CPR value of the motor
master.set_operation_mode(ID, 1) # Sets the operation mode to 'Position Control'
master.set_control_parameters_position(ID, 10, 0, 50) # Sets the PID parameters, can be auto-tuned instead
master.enable_torque(ID, 1) # Enables the motor to spin if any command says so
# Main loop
while True:
# Get distance data from the ultrasonic sensor
distance = master.get_distance(ID, distance_id) # Variable to store the distance data
print(f"Distance: {distance} cm") # Printing the value to observe
if distance < 10: # If it sees a person nearby 10 cm
master.set_position(ID, 1000) # Motor lifts the trash bin lid
time.sleep(2) # Delay before putting the lid down
else:
master.set_position(ID, 0) # Motor puts the lid down
except Exception as e:
print(f"Error: {e}")
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