import machine
import utime

led1 = machine.PWM(machine.Pin(1))
led2 = machine.PWM(machine.Pin(2))
led1.freq(1000)
led2.freq(1000)

for brightness in range(0,65535,50):
    led1.duty_u16(brightness)
    utime.sleep_ms(10)
    led2.duty_u16(brightness)
    utime.sleep_ms(10)

led1.duty_u16(0)
led2.duty_u16(0)