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 <Arduino.h>
#include "DebounceSwitch.h"
#define DEVICE 0 // ! Arduino Nano Every = 0, ESP8266 = 1
// I/O ...
#if DEVICE == 0
// ? Arduino Nano Every
#define LED_BUILTIN 13 // ? built in LED on pin 13
#define LED_ON HIGH // ? active high
#define swPin 12 // ? Arduino Nano Every D12
#define intPullup true // ? use internal pullup resistor?
#elif DEVICE == 1
// ? ESP8266
#define LED_BUILTIN 2 // ? built in LED on pin 2
#define LED_ON LOW // ? active low
#define swPin 13 // ? ESP8266 D7
#define intPullup false // ? use internal pullup resistor?
#endif
#ifndef LED
#define LED LED_BUILTIN
#endif
// configure switch ...
void loCallback(), hiCallback();
DebounceSwitch mySwitch(swPin, intPullup, loCallback, hiCallback);
void setup() {
// establish serial comms ...
Serial.begin(115200);
while(!Serial) {;} // wait for connection
delay(3000); // settling time
Serial.println(); Serial.println("Serial monitor connected.");
Serial.println();
// configure indicator LED ...
pinMode(LED, OUTPUT);
// initialize switch ...
bool swStateInit = mySwitch.initPin();
digitalWrite(LED, swStateInit ? !LED_ON : LED_ON); // ! active low
const char *swStateStr[] = {"LOW", "HIGH"};
Serial.print("Initial input state is ");
Serial.print(swStateStr[swStateInit]);
Serial.println("."); Serial.println();
}
void loop() {
int debounceDelay = 50; // (ms)
mySwitch.readPin(debounceDelay);
}
// callback functions ...
void loCallback() {
digitalWrite(LED, LED_ON); // ! active low
Serial.println("Input just went LOW."); Serial.println();
}
void hiCallback() {
digitalWrite(LED, !LED_ON); // ! active low
Serial.println("Input just went HIGH."); Serial.println();
}
Source: https://www.mischianti.org/2021/04/26/wemos-d1-mini-high-resolution-pinout-and-specs/
Source: https://randomnerdtutorials.com/esp8266-pinout-reference-gpios/
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/
