1  # SPDX-FileCopyrightText: 2022 Noe Ruiz for Adafruit Industries
 2  # SPDX-License-Identifier: MIT
 3  # Adafruit nOOds lantern with "analog" (PWM) brightness control using GPIO.
 4  # Uses 6 nOOds, anode (+) to GPIO pin, cathode (-) to ground.
 5  # A current-limiting resistor (e.g. 10 Ohm) can go at either end.
 6  
 7  import math
 8  import time
 9  import board
10  import pwmio
11  from digitalio import DigitalInOut, Direction, Pull
12  
13  PINS = (board.SCK, board.MOSI, board.A1, board.A3, board.MISO, board.A2) # List of pins
14  GAMMA = 2.6  # For perceptually-linear brightness
15  
16  # Convert pin number list to PWMOut object list
17  pin_list = [pwmio.PWMOut(pin, frequency=1000, duty_cycle=0) for pin in PINS]
18  
19  # Button switch set up
20  switch = DigitalInOut(board.A0)
21  switch.direction = Direction.INPUT
22  switch.pull = Pull.UP
23  
24  # LED set up
25  led = DigitalInOut(board.TX)
26  led.direction = Direction.OUTPUT
27  
28  while True: # Repeat forever...
29      # If the button is pressed turn on LED n00ds
30      if switch.value:
31          for i, pin in enumerate(pin_list): # For each pin...
32              # Calc sine wave, phase offset for each pin, with gamma correction.
33              # If using red, green, blue nOOds, you'll get a cycle of hues.
34              phase = (time.monotonic() - 2 * i / len(PINS)) * math.pi
35              brightness = int((math.sin(phase) + 1.0) * 0.5 ** GAMMA * 65535 + 0.5)
36              pin.duty_cycle = brightness
37          led.value = True # Turn button LED on
38      else: # Otherwise turn LED n00ds off
39          for i, pin in enumerate(pin_list):
40              pin.duty_cycle = 0
41          led.value = False # Turn button LED off
42  
43      time.sleep(.01)