必须接上pca9685模块才能将程序下载进去吗?

mian.py

import time
from machine import Pin, I2C
from servo import Servos

i2c = I2C(sda=Pin(21), scl=Pin(22))#moxing esp32
#i2c = I2C(sda=Pin('P26'), scl=Pin('P25'))#moxing stm32
servo = Servos(i2c, address=0x40, freq=50, min_us=500, max_us=2500, degrees=180)

while True:
for i in range(0, 16):
servo.position(i, 0)
time.sleep_ms(500)
for i in range(0, 16):
servo.position(i, 180)
time.sleep_ms(500)

pca9685.py

import ustruct
import time

class PCA9685:
def init(self, i2c, address=0x40):
self.i2c = i2c
self.address = address
self.reset()

def _write(self, address, value):
    self.i2c.writeto_mem(self.address, address, bytearray([value]))

def _read(self, address):
    return self.i2c.readfrom_mem(self.address, address, 1)[0]

def reset(self):
    self._write(0x00, 0x00) # Mode1

def freq(self, freq=None):
    if freq is None:
        return int(25000000.0 / 4096 / (self._read(0xfe) - 0.5))
    prescale = int(25000000.0 / 4096.0 / freq + 0.5)
    old_mode = self._read(0x00) # Mode 1
    self._write(0x00, (old_mode & 0x7F) | 0x10) # Mode 1, sleep
    self._write(0xfe, prescale) # Prescale
    self._write(0x00, old_mode) # Mode 1
    time.sleep_us(5)
    self._write(0x00, old_mode | 0xa1) # Mode 1, autoincrement on

def pwm(self, index, on=None, off=None):
    if on is None or off is None:
        data = self.i2c.readfrom_mem(self.address, 0x06 + 4 * index, 4)
        return ustruct.unpack('<HH', data)
    data = ustruct.pack('<HH', on, off)
    self.i2c.writeto_mem(self.address, 0x06 + 4 * index,  data)

def duty(self, index, value=None, invert=False):
    if value is None:
        pwm = self.pwm(index)
        if pwm == (0, 4096):
            value = 0
        elif pwm == (4096, 0):
            value = 4095
        value = pwm[1]
        if invert:
            value = 4095 - value
        return value
    if not 0 <= value <= 4095:
        raise ValueError("Out of range")
    if invert:
        value = 4095 - value
    if value == 0:
        self.pwm(index, 0, 4096)
    elif value == 4095:
        self.pwm(index, 4096, 0)
    else:
        self.pwm(index, 0, value)

servo.py

import pca9685
import math

class Servos:
def init(self, i2c, address=0x40, freq=50, min_us=600, max_us=2400,
degrees=180):
self.period = 1000000 / freq
self.min_duty = self._us2duty(min_us)
self.max_duty = self._us2duty(max_us)
self.degrees = degrees
self.freq = freq
self.pca9685 = pca9685.PCA9685(i2c, address)
self.pca9685.freq(freq)

def _us2duty(self, value):
    return int(4095 * value / self.period)

def position(self, index, degrees=None, radians=None, us=None, duty=None):
    span = self.max_duty - self.min_duty
    if degrees is not None:
        duty = self.min_duty + span * degrees / self.degrees
    elif radians is not None:
        duty = self.min_duty + span * radians / math.radians(self.degrees)
    elif us is not None:
        duty = self._us2duty(us)
    elif duty is not None:
        pass
    else:
        return self.pca9685.duty(index)
    duty = min(self.max_duty, max(self.min_duty, int(duty)))
    self.pca9685.duty(index, duty)

def release(self, index):
    self.pca9685.duty(index, 0)

这个源码在openmvIDE上运行时报错，请问是什么问题
错误提示是IOS[Errno 110]ETIMEDOUT