Example Code for Raspberry Pi-Digital Port LED Blink

Hardware Preparation

• Raspberry Pi 4B x1
• IO Expansion HAT for Raspberry Pi x1
• HDMI Cable x1
• Display x1
• Keyboard and Mouse x1
• Gravity: Bright LED Module x1

Software Preparation

• Install RPi.GPIO library:pip install RPi.GPIO

Wiring Diagram

• Plug a LED on the Pin27 on the expansion board.

Sample Code

import RPi.GPIO as GPIO
import time
import atexit
blinkPin=27
atexit.register(GPIO.cleanup)
GPIO.setmode(GPIO.BCM)
GPIO.setup(blinkPin,GPIO.OUT)
while True:
    GPIO.output(blinkPin,GPIO.HIGH)
    time.sleep(1)
    GPIO.output(blinkPin,GPIO.LOW)
    time.sleep(1)

Result

The LED will begin to blink on and off.

Additional Information

IO expansion board offers 28 groups (D0-D27) of digital ports that are led out via Raspberry Pi ports GPIO0~GPIO27 (BCM codes). GPIO Learning Guide.