63 lines
1.9 KiB
Python
63 lines
1.9 KiB
Python
# SPDX-FileCopyrightText: 2022 Dan Halbert for Adafruit Industries
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#
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# SPDX-License-Identifier: MIT
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import asyncio
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import board
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import digitalio
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import keypad
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class Interval:
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"""Simple class to hold an interval value. Use .value to to read or write."""
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def __init__(self, initial_interval):
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self.value = initial_interval
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async def monitor_interval_buttons(pin_slower, pin_faster, interval):
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"""Monitor two buttons: one lengthens the interval, the other shortens it.
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Change interval.value as appropriate.
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"""
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# Assume buttons are active low.
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with keypad.Keys(
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(pin_slower, pin_faster), value_when_pressed=False, pull=True
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) as keys:
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while True:
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key_event = keys.events.get()
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if key_event and key_event.pressed:
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if key_event.key_number == 0:
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# Lengthen the interval.
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interval.value += 0.1
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else:
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# Shorten the interval.
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interval.value = max(0.1, interval.value - 0.1)
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print("interval is now", interval.value)
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# Let another task run.
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await asyncio.sleep(0)
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async def blink(pin, interval):
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"""Blink the given pin forever.
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The blinking rate is controlled by the supplied Interval object.
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"""
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with digitalio.DigitalInOut(pin) as led:
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led.switch_to_output()
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while True:
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led.value = not led.value
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await asyncio.sleep(interval.value)
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async def main():
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# Start blinking 0.5 sec on, 0.5 sec off.
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interval = Interval(0.5)
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led_task = asyncio.create_task(blink(board.D1, interval))
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interval_task = asyncio.create_task(
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monitor_interval_buttons(board.D3, board.D4, interval)
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)
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# This will run forever, because neither task ever exits.
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await asyncio.gather(led_task, interval_task)
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asyncio.run(main())
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