from machine import Pin, PWM
from time import sleep_ms
 

led = Pin(4)
pwm_led = PWM(led)

while 1:
    for i in range(1023, -1, -1):
        pwm_led.duty(i)
        sleep_ms(1)
    for i in range(1024):
        pwm_led.duty(i)
        sleep_ms(1)
esp:0
esp:1
esp:2
esp:3
esp:4
esp:5
esp:6
esp:7
esp:8
esp:9
esp:10
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esp:13
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esp:20
esp:21
esp:35
esp:36
esp:37
esp:38
esp:39
esp:40
esp:41
esp:42
esp:45
esp:46
esp:47
esp:48
esp:3V3.1
esp:3V3.2
esp:RST
esp:5V
esp:GND.1
esp:GND.2
esp:TX
esp:RX
esp:GND.3
esp:GND.4
led1:A
led1:C
r1:1
r1:2