1  # SPDX-FileCopyrightText: 2019 Carter Nelson for Adafruit Industries
 2  #
 3  # SPDX-License-Identifier: MIT
 4  
 5  # Example code for using analog feedback value to seek a position
 6  import board
 7  import pwmio
 8  from simpleio import map_range
 9  from adafruit_motor import servo
10  from analogio import AnalogIn
11  
12  # Demo angles
13  angles = [0, 180, 0, 45, 180]
14  
15  # Pin setup
16  SERVO_PIN = board.A1
17  FEEDBACK_PIN = board.A5
18  
19  # Calibration setup
20  CALIB_MIN = 18112
21  CALIB_MAX = 49408
22  ANGLE_MIN = 0
23  ANGLE_MAX = 180
24  
25  # Setup servo
26  pwm = pwmio.PWMOut(SERVO_PIN, duty_cycle=2 ** 15, frequency=50)
27  servo = servo.Servo(pwm)
28  servo.angle = None
29  
30  # Setup feedback
31  feedback = AnalogIn(FEEDBACK_PIN)
32  
33  def get_position():
34      return map_range(feedback.value, CALIB_MIN, CALIB_MAX, ANGLE_MIN, ANGLE_MAX)
35  
36  def seek_position(position, tolerance=2):
37      servo.angle = position
38  
39      while abs(get_position() - position) > tolerance:
40          pass
41  
42  print("Servo feedback seek example.")
43  for angle in angles:
44      print("Moving to {}...".format(angle), end="")
45      seek_position(angle)
46      print("Done.")