1  # SPDX-FileCopyrightText: 2018 Bill Earl and Mikey Sklar for Adafruit Industries
 2  #
 3  # SPDX-License-Identifier: MIT
 4  #
 5  # Bionic Eye sketch for Adafruit Trinket.
 6  #
 7  # written by Bill Earl for Arduino
 8  # ported to CircuitPython by Mikey Sklar
 9  # for Adafruit Industries
10  #
11  # Required library is the Adafruit_SoftServo library
12  # available at https://github.com/adafruit/Adafruit_SoftServo
13  # The standard Arduino IDE servo library will not work with 8 bit
14  # AVR microcontrollers like Trinket and Gemma due to differences
15  # in available timer hardware and programming. We simply refresh
16  # by piggy-backing on the timer0 millis() counter
17  #
18  # Trinket:        Bat+    Gnd       Pin #0  Pin #2
19  # Connection:     Servo+  Servo-    Tilt    Rotate
20  #                 (Red)   (Black)   Servo   Servo
21  #                                   (Orange)(Orange)
22  
23  import time
24  import random
25  import board
26  import pwmio
27  from adafruit_motor import servo
28  
29  # we are intentionally avoiding Trinket Pin #1 (board.A0)
30  # as it does not have PWM capability
31  tilt_servo_pin = board.A2   # servo control line (orange) Trinket Pin #0
32  rotate_servo_pin = board.A1 # servo control line (orange) Trinket Pin #2
33  
34  # servo object setup for the M0 boards:
35  tilt_pwm = pwmio.PWMOut(tilt_servo_pin, duty_cycle=2 ** 15, frequency=50)
36  rotate_pwm = pwmio.PWMOut(rotate_servo_pin, duty_cycle=2 ** 15, frequency=50)
37  tilt_servo = servo.Servo(tilt_pwm)
38  rotate_servo = servo.Servo(rotate_pwm)
39  
40  # servo timing and angle range
41  tilt_min = 120      # lower limit to tilt rotation range
42  max_rotate = 180    # rotation range limited to half circle
43  
44  while True:
45  
46      # servo tilt - on average move every 500ms
47      if random.randint(0,100) > 80:
48          tilt_servo.angle = random.randint(tilt_min, max_rotate)
49          time.sleep(.25)
50  
51      # servo rotate - on average move every 500ms
52      if random.randint(0,100) > 90:
53          rotate_servo.angle = random.randint(0, max_rotate)
54          time.sleep(.25)