cpp 
#include "M5Unified.h"

void setup() {
    M5.begin();
    Serial.begin(115200);
}

void loop() {
    M5.update();

    if (M5.BtnA.wasPressed()) {
        Serial.println("BtnA was pressed");
    }
    if (M5.BtnA.wasReleased()) {
        Serial.println("BtnA was released");
    }
    if (M5.BtnA.wasSingleClicked()) {
        Serial.println("BtnA was single clicked");
    }
    if (M5.BtnA.wasDoubleClicked()) {
        Serial.println("BtnA was double clicked");
    }
    if (M5.BtnA.wasHold()) {
        Serial.println("BtnA was held");
    }
}

The sketch detects front-button events (press, release, single click, double click, hold) and prints example messages to the serial monitor, for example:

BtnA was pressed
BtnA was released
BtnA was single clicked
BtnA was pressed
BtnA was held
BtnA was released 

API

The button API is provided by the Button_Class in M5Unified. See:

M5Unified - Button Class

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