Dual Button Unit

The Dual Button Unit provides two independent buttons. Use DualButtonUnit for click, double-click, hold, and callback handling, or SimpleDualButtonUnit for direct pin reads and debounced edge polling.

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UiFlow2 Example

Button events

Open the dual_button_core_example.m5f2 project in UiFlow2.

This example demonstrates how to read the button state and handle button events in UiFlow2.

UiFlow2 Code Block:

Example output:

The button state is shown when a button event occurs.

MicroPython Example

Button events and callbacks

This example demonstrates how to use DualButtonUnit for button state, click, hold, and callback handling.

MicroPython Code Block:

import os, sys, io
import M5
from M5 import *
from unit import DualButtonUnit


dual_button_0_blue = None
dual_button_0_red = None


def dual_button_0_blue_wasClicked_event(state):  # noqa: N802
    global dual_button_0_blue, dual_button_0_red
    print(dual_button_0_blue.isHolding())


def setup():
    global dual_button_0_blue, dual_button_0_red

    M5.begin()
    Widgets.fillScreen(0x222222)

    dual_button_0_blue, dual_button_0_red = DualButtonUnit((36, 26))
    dual_button_0_blue.setCallback(
        type=dual_button_0_blue.CB_TYPE.WAS_CLICKED, cb=dual_button_0_blue_wasClicked_event
    )
    print(dual_button_0_blue.isHolding())


def loop():
    global dual_button_0_blue, dual_button_0_red
    M5.update()
    dual_button_0_blue.tick(None)


if __name__ == "__main__":
    try:
        setup()
        while True:
            loop()
    except (Exception, KeyboardInterrupt) as e:
        try:
            from utility import print_error_msg

            print_error_msg(e)
        except ImportError:
            print("please update to latest firmware")

Example output:

The button state is printed when the blue button event occurs.

Simple polling

This example demonstrates how to use SimpleDualButtonUnit to read the pins directly and poll debounced press and release edges without tick() or callbacks.

MicroPython Code Block:

import os, sys, io
import time

import M5
from M5 import *
from unit import SimpleDualButtonUnit


blue = None
red = None


def setup():
    global blue, red

    M5.begin()
    Widgets.fillScreen(0x222222)

    blue, red = SimpleDualButtonUnit((36, 26))


def loop():
    global blue, red
    M5.update()
    blue.update()
    red.update()

    if blue.was_pressed():
        print("blue pressed, pin value:", blue.value())
    if blue.was_released():
        print("blue released, active:", blue.is_active())

    if red.was_pressed():
        print("red pressed, pin value:", red.value())
    if red.was_released():
        print("red released, active:", red.is_active())

    time.sleep_ms(10)


if __name__ == "__main__":
    try:
        setup()
        while True:
            loop()
    except (Exception, KeyboardInterrupt) as e:
        try:
            from utility import print_error_msg

            print_error_msg(e)
        except ImportError:
            print("please update to latest firmware")

Example output:

Press and release events for the blue and red buttons are printed.

API

DualButtonUnit

DualButtonUnit(port)

Create two full-featured button objects.

Parameters:

port (tuple) – Two button pin numbers.

Returns:

The blue and red hardware.Button objects.

Return type:

tuple

UiFlow2 Code Block:

Dual_Button.isHolding()

Return whether the button is currently being held.

UiFlow2 Code Block:

Dual_Button.setCallback(type, cb)

Register a callback for the specified button event.

Parameters:

• type (int) – Button event type.

• cb (callable) – Function called when the event occurs.

UiFlow2 Code Block:

Dual_Button.tick(pin)

Poll the button state machine. Call this method regularly in the loop.

Parameters:

pin – Optional pin argument passed by an interrupt handler. Use None when polling from the loop.

UiFlow2 Code Block:

SimpleDualButtonUnit

SimpleDualButtonUnit(port, active_low=True, debounce_ms=50)

Create two SimpleButton objects for direct polling.

Parameters:

• port (tuple) – Two button pin numbers.

• active_low (bool) – Use low level as the active state when True. Active-low inputs use an internal pull-up and active-high inputs use an internal pull-down.

• debounce_ms (int) – Time in milliseconds that an input must remain stable before generating an edge event. Set to 0 to disable debounce.

Returns:

The blue and red button objects.

Return type:

tuple

SimpleButton

class SimpleButton(pin_num, active_low=True, debounce_ms=50)

Provide direct pin reads and debounced edge polling without callbacks.

Call SimpleButton.update() regularly before reading edge events. The SimpleButton.value() and SimpleButton.is_active() methods read the pin directly and do not require update().

value()

Return the raw pin value.

Returns:

0 or 1.

Return type:

int

is_active()

Return whether the button is currently active according to active_low.

Returns:

True when the button is active.

Return type:

bool

update()

Sample the pin and update the debounced edge state. Call this method once per loop iteration.

was_pressed()

Return whether a debounced press was detected by the latest call to SimpleButton.update().

Return type:

bool

was_released()

Return whether a debounced release was detected by the latest call to SimpleButton.update().

Return type:

bool