chumicro-buttons¶

Buttons that catch the press even when your loop is busy.

Wire a button to a pin, read button.just_pressed in the loop you already wrote, and the press lands whether your program was idle or halfway through a slow network call. Debouncing, long presses, auto-repeat, and double-click counting come with it, and the same code runs on CircuitPython, MicroPython, and your laptop.

Quick example¶

import board
import digitalio
from chumicro_buttons import Button
from chumicro_timing import ticks, ticks_ms

button = Button(pin=board.GP14, ticks=ticks)

led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT

while True:
    now = ticks_ms()
    button.check(now)

    if button.just_pressed:
        led.value = not led.value

just_pressed is true for exactly one pass of the loop, so you can read it as often as you like without it firing twice.

In a program with more going on, hand the loop to chumicro-runner and let callbacks do the reading:

from chumicro_runner import Runner

button.on_press = lambda: print("pressed")

runner = Runner()
runner.add(button)

while True:
    now = runner.tick()
    runner.wait(now)

tick() gives every registered service one small step and dispatches your callbacks; wait() parks the CPU until the next event, waking exactly when a long press, a repeat, or a click window is due.

Documentation¶

• User Guide: wiring a button, debouncing in software and in hardware, long presses and repeats, several keys at once, and wiring into a runner
• API Reference: every public class and method, generated from the source docstrings
• Testing Helpers: writing button logic as a unit test with FakeButtonSource