led_blink.py
The classic first GPIO build: an LED with a 330-ohm resistor blinks once per second via gpiozero. The script imports LED, targets GPIO17 (pin 11) and toggles it in a loop. Ideal to check the power supply (format compact, Wi-Fi 2,4/5 GHz, alimentation USB-C 5 V/2,5 A) before a bigger project.
Hardware
A Raspberry Pi 3 Model A+ (compact format, BCM2837B0, 5 GHz Wi-Fi + Bluetooth, a single USB port, 5 V/700 mA power, 40-pin GPIO). One red LED, a 330-ohm resistor, dupont wires (40-pin header).
Wiring
LED anode (long leg) to GPIO17 through the resistor, cathode to any GND pin of the J8 connector.
How it works
gpiozero sets the pin as output; led.on/off drive it to 3.3 V or 0 V. KeyboardInterrupt cleans up on exit.
Running it
Copy the script to the board (scp), then run it with python3 (or bash). Raspberry Pi OS ships gpiozero; otherwise sudo apt install python3-gpiozero. Mind the 700 mA power budget for USB peripherals.
Variants
Use led.blink(0.2, 0.8) for an asymmetric pattern; chain several LEDs for a scroller. Compact board to cool; USB-C 5 V/2.5 A; a single USB port, add a hub if needed.
led_blink.py
# led_blink.py — fait clignoter une LED via gpiozero.
# Deps: sudo apt install python3-gpiozero
# Montage : LED + resistance 330 ohms sur GPIO17 (broche 11), GND sur GND.
from gpiozero import LED
from time import sleep
LED_PIN = 17 # numero GPIO, pas numero de broche
ON_TIME = 0.5
OFF_TIME = 0.5
led = LED(LED_PIN)
print(f"Clignotement GPIO{LED_PIN}, Ctrl+C pour terminer")
try:
while True:
led.on()
sleep(ON_TIME)
led.off()
sleep(OFF_TIME)
except KeyboardInterrupt:
print("Arret propre")
led.off()