DebounceSwitch

A c++ class for de-bouncing a mechanical switch.

• The required parameters are:

  • the GPIO input pin #
  • a flag that's true if using an internal pullup resistor, or false otherwise
  • a pair of callback functions that get called when the input pin goes either low or high
  • a debounce delay in milliseconds

• The initPin() member function must be called first. It configures the input pin, and returns the inital state of the switch.

• The readPin(debounceDelay) member function returns the current state (de-bounced), and calls the appropriate callback function whenever the pin's state changes.

#include "DebounceSwitch.h"

#define swPin 12                
#define intPullup true          // ! use internal pullup resistor?

void loCallback(), hiCallback();
DebounceSwitch mySwitch(swPin, intPullup, loCallback, hiCallback);

void setup() {
.
.
. 
  bool swStateInit = mySwitch.initPin();  // initialize switch
}

void loop() {
  int debounceDelay = 50;       // (ms)
  bool swState = mySwitch.readPin(debounceDelay); 
}

void loCallback() {
  Serial.println("Input just went LOW.");
}

void hiCallback() {
  Serial.println("Input just went HIGH.");
}

Included is an example Platform IO project. You can choose between platforms using a single pre-processor statement. Be sure to select the correct environment before compiling - see the screenshots below.

[env:nano_every]
platform = atmelmegaavr
board = nano_every
framework = arduino
monitor_speed = 115200

[env:esp12e]
platform = espressif8266
board = esp12e
framework = arduino
monitor_speed = 115200

Digital Inputs: Pullup vs. Pulldown Resistors

ESP8266 D1 Mini Pinout

Source: https://www.mischianti.org/2021/04/26/wemos-d1-mini-high-resolution-pinout-and-specs/

Source: https://randomnerdtutorials.com/esp8266-pinout-reference-gpios/

ESP32 Dev Kit C v4 Pinout

Source: https://forum.fritzing.org/t/esp32s-hiletgo-dev-boad-with-pinout-template/5357

Source: https://www.mischianti.org/2021/07/17/esp32-devkitc-v4-high-resolution-pinout-and-specs/

Arduino Nano Every Pinout

Source: https://docs.arduino.cc/hardware/nano-every/