clignotante.py
The first MicroPython program: the LED blinks once per second with serial console tracing. It shows Pin as output, value() and time.sleep, the basis of every embedded script on the board.
Hardware
A Raspberry Pi Pico W (RP2040 + 2.4 GHz Wi-Fi radio chip) with MicroPython installed, powered over USB. No external part (external LED + 330 Ω resistor only if the user LED is unavailable).
Wiring
External LED anode to GP15 through a 330 Ω resistor, cathode to GND. The user LED is driven by the radio chip, not a GPIO.
How it works
Pin(LED_PIN, Pin.OUT) sets the pin as output. The infinite loop alternates value(1)/value(0) with a one-second pause; print() goes to the USB serial (Thonny).
Running it
Install the « Pico W » MicroPython build (BOOTSEL + .uf2), copy the script via Thonny. Since the user LED sits behind the radio chip, output examples use an external LED.
Variants
Save as main.py for auto-start, or replace sleep(1) with sleep_ms(100) for fast blinking.
clignotante.py
# Clignotement d'une LED avec MicroPython (module machine.Pin).
# LED externe sur GP15 (la LED utilisateur est portee par la puce radio)
from machine import Pin
import time
LED_PIN = 15
led = Pin(LED_PIN, Pin.OUT) # broche en sortie numerique
print("Clignotement demarre sur GP" + str(LED_PIN))
compteur = 0
while True:
led.value(1) # LED allumee
compteur += 1
print("LED ON (cycle %d)" % compteur)
time.sleep(1) # 1 seconde
led.value(0) # LED eteinte
print("LED OFF")
time.sleep(1)
# Pour arreter : bouton Stop dans Thonny (le script tourne aussi
# tout seul s'il est enregistre sous main.py sur la carte).