import utime
from machine import Pin

# Define pin for LED or any output device
led = Pin(21, Pin.OUT)  # GPIO 15 on Pico Pi W

# Set PWM parameters
frequency = 1000  # Frequency in Hz (1 kHz by default)
duty_cycle = 50   # Initial duty cycle in percentage (0 to 100)

def generate_pwm(frequency, duty_cycle, duration_ms=1000):
    # Ensure duty cycle is between 0 and 100
    if duty_cycle < 0:
        duty_cycle = 0
    elif duty_cycle > 240:
        duty_cycle = 240

    # Calculate period and times in microseconds
    period_us = int(1_000_000 / frequency)  # Period in microseconds
    high_time_us = int(period_us * (duty_cycle / 100))  # HIGH time in microseconds
    low_time_us = period_us - high_time_us  # LOW time in microseconds

    # Generate PWM for the specified duration in milliseconds
    start_time = utime.ticks_ms()
    while utime.ticks_ms() - start_time < duration_ms:
        # Set HIGH
        led.value(1)
        utime.sleep_us(high_time_us)

        # Set LOW
        led.value(0)
        utime.sleep_us(low_time_us)

# Main loop to generate PWM with changing duty cycle
while True:
    duty_cycle=int(input("Enter Duty Cycle (50-240): "))
    generate_pwm(frequency, duty_cycle, duration_ms=500)