from machine import Pin, PWM
import time

servo = PWM(Pin(15))
servo.freq(50)

def set_angle(angle):
    # Typical Pico duty_u16 uses 0..65535; mapping depends on servo pulse widths.
    # Using a conservative mapping: 0.5ms -> 2.5% ; 2.5ms -> 12.5% at 50Hz
    min_u16 = int(0.025 * 65535)  # adjust if needed
    max_u16 = int(0.125 * 65535)
    duty = int(min_u16 + (angle / 180.0) * (max_u16 - min_u16))
    servo.duty_u16(duty)

while True:
    # sweep from 30 to 150 and back
    for angle in range(30, 181, 5):
        set_angle(angle)
        time.sleep(0.05)
    for angle in range(150, 29, -5):
        set_angle(angle)
        time.sleep(0.02)