from machine import Pin, PWM
import time

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

while True:
    for G in range (500000, 2500000, 10000)
    ServoM.duty_ns(G)
    time.sleep_ms(1)

   # for G in range (2500000, 500000, -3000)
    #ServoM.duty_ns(G)
    #time.sleep_ms(1)