from machine import Pin, PWM
from utime import sleep
led1 = machine.PWM(machine.Pin(5))
led2 = machine.PWM(machine.Pin(7))
led1.freq(100000)
led2.freq(100000)
for b in range (0,65535,50):
    led1.duty_u16(b)
    led2.duty_u16(65535-b)
    sleep(0.1)
led1.duty_u16(0)
led2.duty_u16(0)