Arduino Helpers master
Utility library for Arduino
CountPressedButtons.ino

CountPressedButtons

Example of using the standard library algorithms and the Button class.

Boards:
AVR, AVR USB, Nano Every, Nano 33 IoT, Nano 33 BLE, UNO R4, Pi Pico, Due, Teensy 3.x, ESP8266, ESP32

This sketch reads a number of push buttons or switches, and uses the standard library algorithms to count how many of them are pressed.

The internal pull-up resistors are enabled and the switches are debounced.

Written by PieterP, 2019-11-24
https://github.com/tttapa/Arduino-Helpers

#include <AH/Hardware/Button.hpp> // Button
#include <AH/STL/numeric> // std::accumulate
// An array of debounced buttons connected to the given pins
Button buttons[] {
2, 3, 4, 5, 6, 7, 8, 9,
};
void setup() {
for (auto &button : buttons) // for all buttons in the array
button.begin(); // initialize (enable internal pull-up resistor)
Serial.begin(115200);
}
void loop() {
// function that adds one to the counter if the given button is pressed
auto addOneIfPressed = [](unsigned count, const Button &button) {
return button.getState() == Button::Pressed ? count + 1 : count;
};
// read all buttons and debounce them
for (auto &button : buttons)
button.update();
// apply that function to all buttons and return the count
unsigned pressed =
std::accumulate(std::begin(buttons), // from the first button
std::end(buttons), // to the last
0u, // initial value of the counter
addOneIfPressed); // counter function to apply
Serial.println(pressed);
}
Dummy header file for Arduino builder.
A class for reading and debouncing buttons and switches.
Definition: Button.hpp:15
@ Pressed
Input went from low to low (0,0)
Definition: Button.hpp:46
void begin()
Initialize (enable the internal pull-up resistor).
Definition: Button.cpp:7