Hardware Setup

1. Identify the two pins of the LED:

   • The longer pin is the positive terminal (anode).
   • The shorter pin is the negative terminal (cathode).

2. Connect the negative terminal (shorter pin) to the GND pin of the Raspberry Pi.

3. Connect the positive terminal (longer pin) to a separate line on the breadboard.

4. Attach one end of a resistor to the same line as the positive LED terminal.

5. Connect the other end of the resistor to a GPIO pin on the Raspberry Pi (e.g., GPIO17).

   

Software Setup

1. Controlling the LED with Python 3 on Raspberry Pi OS

Once the hardware is set up, the LED can be controlled using Python 3. The following process enables LED control:

• Import the RPi.GPIO module for GPIO access.
• Import the time module for delays.
• Define a global constant for the LED’s GPIO pin number.
• Configure the Raspberry Pi to use BCM numbering (GPIO numbers).
• Set up the GPIO pin as an output using GPIO.setup().

2. Making the LED Blink

• Maintain the same GPIO configuration.
• Implement an infinite loop that toggles the LED on and off at set intervals.
• The LED remains ON for 1 second and OFF for 2 seconds.
• The loop runs indefinitely until manually stopped using the stop button in the Thonny IDE or CTRL+C in the terminal.

Booting the Raspberry Pi OS

Before setting up the LED, ensure your Raspberry Pi is ready with a working operating system.

1. Prepare the microSD Card

   • Download the Raspberry Pi Imager on your computer.
   • Insert a microSD card (8 GB or larger).
   • In Raspberry Pi Imager, select the desired OS (e.g., Raspberry Pi OS 32-bit), choose your microSD card, and click Write.

2. Insert the microSD Card

   • Safely eject it from your computer and insert it into the Raspberry Pi’s microSD slot.

3. Connect Peripherals

   • Attach a monitor via HDMI.
   • Connect a USB keyboard and mouse.
   • Optionally, connect Ethernet (Wi-Fi can be set up later).

4. Power On

   • Connect the Raspberry Pi to its power supply.
   • The system will boot into Raspberry Pi OS setup automatically.

5. First-Time Setup

   • Follow the on-screen prompts to set your language, keyboard layout, Wi-Fi, and software updates.

Once the OS is up and running, proceed to the hardware setup.

Python Code Implementation

import RPi.GPIO as GPIO
          import time
          
          # Define the GPIO pin number for the LED
          LED_PIN = 17
          
          # Set the GPIO mode to BCM (Broadcom pin-numbering scheme)
          GPIO.setmode(GPIO.BCM)
          
          # Set up the LED pin as an output
          GPIO.setup(LED_PIN, GPIO.OUT)
          
          try:
              while True:
                  # Turn the LED on (HIGH state)
                  GPIO.output(LED_PIN, GPIO.HIGH)
                  time.sleep(1)  # Wait for 1 second
          
                  # Turn the LED off (LOW state)
                  GPIO.output(LED_PIN, GPIO.LOW)
                  time.sleep(2)  # Wait for 2 seconds
          
          except KeyboardInterrupt:
              # Clean up GPIO settings when exiting the program
              GPIO.cleanup()