Action - Reaction
The LED toggle application with a button is the most used project for simple input/output project example. This project allows the user to control the RGB LED Module with the Button Module by simply toggling an LED.

About Tools and Materials:
SMD USB Gateway (Purchase Here)
Arduino Gateway Module (Purchase Here)
RGB LED 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 button module and toggle the RGB LED Module.
The RGB LED Module is designed to emit different colors, allowing users to experiment with different lighting effects.
The Button Module is the physical interface for receiving input from the user. The input can be used to trigger the script in an encoded way.
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 Button Module and toggle the LED on the RGB LED Module.
Project Key Features
A Basic Physical Interaction
The application supports a toggle functionality, allowing the user to press the button to toggle the LED. This provides a simple physical interaction with project.
Visualizing the Input
The RGB LED Module serves as a visual indicator of the current state of the Button Module. When the button is pressed, the LED turns on; when the button is not pressed, the LED turns off.
Step 2: Assemble
Getting Started
Hardware Setup
Connect the SMD to the PC or Arduino board using USB Gateway Module or Arduino Gateway Module.
Connect the RGB LED Module and the Button 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
Run the script on your computer. This will establish communication with the SMD and initiate control of the Button Module and RGB LED Module.
Toggle LED State
Press the button on the Button Module to toggle the RGB LED. Observe the visual feedback of the LED.
Codes
from serial.tools.list_ports import comports
from platform import system
from smd.red import *
baudrate = 115200 # Baud rate of communication
ID = 0 # ID of the SMD
rgb_module_id = 5 # ID of the RGB LED module
button_module_id = 5 # ID of the button 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, desc, hwid in sorted(ports):
# Check if the port matches any known USB names
if any(name in port or name in desc for name in usb_names.get(os_name, [])):
print(f"USB device detected on port: {port}")
return port # 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, desc, hwid in ports:
print(f"Port: {port}, Description: {desc}, HWID: {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
master.scan_modules(ID) # Scans and identifies the modules connected to the SMD
# Main loop
while True:
# Get the button state from the SMD
button_state = master.get_button(ID, button_module_id)
if button_state == 1:
# Set the RGB LED to red
master.set_rgb(ID, rgb_module_id, 255, 0, 0) # RGB values for red
else:
# Turn off the RGB LED
master.set_rgb(ID, rgb_module_id, 0, 0, 0) # RGB values for off
except Exception as e:
print(f"Error: {e}")
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