I use mu editor, when I connect PCA9685 to microbit with slave address "0x41". The microbit gives me that "no module pca9685".

from microbit import sleep, i2c

import PCA9685
import servo

Initialise the PCA9685 using the default address (0x40).

#PCA9685_ADDR = 0x41
#pwm = PCA9685.PCA9685(i2c)
pwm = PCA9685.PCA9685(i2c)

Configure min and max servo pulse lengths (will need to adjust for different servos)

servo_min = 150 # Min pulse length out of 4096
servo_max = 600 # Max pulse length out of 4096:

Set frequency to 60hz, good for servos.

pwm.set_pwm_freq(60)

print('Moving servo on channel 0, press Ctrl-C to quit...')

Move servo on channel O between extremes.

pwm.set_pwm(4, 0, servo_min)
sleep(1000)
pwm.set_pwm(4, 0, servo_max)
sleep(1000)

Use servo helper class to move channel 0 by degrees

s0 = servo.Servos(i2c)
s0.position(0, 90)
sleep(1000)
s0.release(0)

First of all, thank you very much for your attention. Please help me solve this problem.

I brushed this program into micro:bit, micro:bit shows OSError, i2c.write error -1010.

Thank you very much。

In the module PCA9685.py, in the duty() definition, there is an attempt to use set_pwm() without on and off arguments.