import machine
import utime

# Configure PWM parameters
PWM_PIN = 19  # Change this to the desired PWM output pin
PWM_FREQ_HZ = 50000  # Set the desired PWM frequency in Hz
DUTY_CYCLE_PERCENT = 50  # Set the duty cycle as a percentage (0-100)

# Initialize PWM on the specified pin
pwm = machine.PWM(machine.Pin(PWM_PIN), freq=PWM_FREQ_HZ)

try:
    while True:
        # Vary the duty cycle to create a pulsating PWM signal
        for duty_cycle in range(0, 101, 5):
            pwm.duty(duty_cycle)  # Set the duty cycle
            utime.sleep(0.1)  # Delay for a short period

        # Reverse the duty cycle to go from 100% to 0%
        for duty_cycle in range(100, -1, -5):
            pwm.duty(duty_cycle)
            utime.sleep(0.1)

except KeyboardInterrupt:
    pass

# Turn off PWM and release the pin
pwm.deinit()