Control onboard LED of Raspberry Pi Pico 2/2W using MicroPython/CircuitPython

The onboard LED on Raspberry Pi Pico and Pico 2 is connected to GPIO25. On Pico W and Pico 2 W, it's connected to the wireless chip.

Following are exercise to control the onboard LED using MicroPython/CircuitPython, tested on Pico 2 and Pico 2 W.

mpy_rp2_led.py

"""
MicroPython on Raspberry Pi Pico 2/2W
to control onboard LED
"""
import os, sys
import time
#import board
#from digitalio import DigitalInOut, Direction

sys_info_text = sys.implementation[0] + " " + os.uname()[3] +\
                "\nrun on " + os.uname()[4]
print("=======================================")
print(sys_info_text)
print("=======================================")

led = machine.Pin("LED", machine.Pin.OUT)
print("led:", led)

# Control onboard led using led.on() and led.off()
while True:
    led.on()
    time.sleep(0.5)
    led.off()
    time.sleep(0.5)
"""
# Toggle onboard led using led.toggle()
while True:
    led.toggle()
    time.sleep(0.2)
"""

"""
# Toggle led in callback using Timer
from machine import Timer
timer = Timer()

def blink(timer):
    led.toggle()
    
timer.init(freq=10, mode=Timer.PERIODIC, callback=blink)

while True:
    pass
"""

"""
# using  PWM
# Not work for 'W'
from machine import PWM

pwm = PWM(led)
print("pwm type", type(pwm))
pwm.freq(1000)

while True:
    for brightness in range(0, 10000, 500):
        pwm.duty_u16(brightness)
        print("brightness:", brightness, end="\r")
        time.sleep(0.1)
    for brightness in range(10000, 0, -500):
        pwm.duty_u16(brightness)
        print("brightness:", brightness, end="\r")
        time.sleep(0.1)
"""

cpy_rp2_led.py

"""
CircuitPython on Raspberry Pi Pico 2/2W
to control onboard LED
"""
import os, sys
import time
import board
from digitalio import DigitalInOut, Direction

sys_info_text = sys.implementation[0] + " " + os.uname()[3] +\
                "\nrun on " + os.uname()[4]
print("=======================================")
print(sys_info_text)
print("=======================================")

led = DigitalInOut(board.LED)
led.direction = Direction.OUTPUT
print("board.LED:", type(board.LED))

# Turn onboard LED ON/OFF by value
while True:
    led.value =True
    time.sleep(0.5)
    led.value = False
    time.sleep(0.5)

"""
# Toggle onboard LED
while True:
    led.value = not led.value
    time.sleep(0.25)
"""

cpy_rp2_led_pwm.py

"""
CircuitPython on Raspberry Pi Pico 2/2W
to control onboard LED using PWM
"""
import os, sys
import board
import pwmio
import time

sys_info_text = sys.implementation[0] + " " + os.uname()[3] +\
                "\nrun on " + os.uname()[4]
print("=======================================")
print(sys_info_text)
print("=======================================")
print("board.LED:", type(board.LED))
led = pwmio.PWMOut(board.LED, frequency=1000, duty_cycle=0)


# Control brightness using PWM
# not work on Raspberry Pi Pico 2 W
while True:
    for brightness in range(0, 10000, 500):
        led.duty_cycle=brightness
        print("brightness:", brightness, end="\r")
        time.sleep(0.1)
    for brightness in range(10000, 0, -500):
        led.duty_cycle=brightness
        print("brightness:", brightness, end="\r")
        time.sleep(0.1)