feat: add support for active-HIGH and active-LOW

Author: JMax45

ArduinoButton.cpp

@@ -9,7 +9,7 @@
 #include "Arduino.h"
 #include "ArduinoButton.h"
 
-ArduinoButton::ArduinoButton(int buttonPin) {
+ArduinoButton::ArduinoButton(int buttonPin, bool isActiveLow) {
   setButtonPin(buttonPin);
   keyUpCallback = NULL;
   keyDownCallback = NULL;
@@ -19,6 +19,7 @@ ArduinoButton::ArduinoButton(int buttonPin) {
   setDoubleClickDelay(0);
   setDebounceDelay(20);
   setLastDebounceTime(millis());
+  setIsActiveLow(isActiveLow);
 }
 
 void ArduinoButton::loop() {
@@ -32,10 +33,10 @@ void ArduinoButton::loop() {
   }
 
   if(val == lastReading &&  millis() - lastDebounceTime >= debounceDelay) {
-    if(keyUpCallback != NULL && val == LOW && prevState == HIGH) keyUpCallback();
-    if(keyDownCallback != NULL && val == HIGH && prevState == LOW) keyDownCallback();
-    if(doubleClickCallback != NULL && val == HIGH && prevState == LOW && millis() - lastKeyDown <= doubleClickDelay) doubleClickCallback();
-    else if (doubleClickCallback != NULL && val == HIGH && prevState == LOW) lastKeyDown = millis();
+    if(keyUpCallback != NULL && val == normalizeButtonState(LOW) && prevState == normalizeButtonState(HIGH)) keyUpCallback();
+    if(keyDownCallback != NULL && val == normalizeButtonState(HIGH) && prevState == normalizeButtonState(LOW)) keyDownCallback();
+    if(doubleClickCallback != NULL && val == normalizeButtonState(HIGH) && prevState == normalizeButtonState(LOW) && millis() - lastKeyDown <= doubleClickDelay) doubleClickCallback();
+    else if (doubleClickCallback != NULL && val == normalizeButtonState(HIGH) && prevState == normalizeButtonState(LOW)) lastKeyDown = millis();
     prevState = val;
   }
   else return;
@@ -73,3 +74,11 @@ void ArduinoButton::setDebounceDelay(int delay) {
 void ArduinoButton::setLastDebounceTime(unsigned long time) {
   lastDebounceTime = time;
 }
+
+void ArduinoButton::setIsActiveLow(bool activeLow) {
+  isActiveLow = activeLow;
+}
+
+bool ArduinoButton::normalizeButtonState(bool state) {
+  return isActiveLow ? (state == HIGH ? LOW : HIGH) : state;
+}

ArduinoButton.h

@@ -24,8 +24,10 @@ class ArduinoButton
     int debounceDelay;
     unsigned long lastDebounceTime;
     bool lastReading;
+    bool isActiveLow;
+    bool normalizeButtonState(bool state);
   public:
-    ArduinoButton(int buttonPin);
+    ArduinoButton(int buttonPin, bool isActiveLow);
     void loop();
     void onKeyUp(void (*cb)());
     void onKeyDown(void (*cb)());
@@ -35,6 +37,7 @@ class ArduinoButton
     void setDoubleClickDelay(int delay);
     void setDebounceDelay(int delay);
     void setLastDebounceTime(unsigned long time);
+    void setIsActiveLow(bool aciveLow);
 };
 
 #endif

examples/DoubleClick/DoubleClick.ino

@@ -1,11 +1,13 @@
 #include <ArduinoButton.h>
 
-#define BUTTON_PIN 7
+#define BUTTON_PIN 6
 
-ArduinoButton button(BUTTON_PIN);
+// This example uses the internal pull-up resistor in the Arduino
+ArduinoButton button(BUTTON_PIN, true);
 
 void setup() {
   Serial.begin(9600);
+  pinMode(BUTTON_PIN, INPUT_PULLUP);
   button.onDoubleClick([]() {
     Serial.println("Button double click callback");
   });

examples/KeyDown/KeyDown.ino

@@ -1,11 +1,13 @@
 #include <ArduinoButton.h>
 
-#define BUTTON_PIN 7
+#define BUTTON_PIN 6
 
-ArduinoButton button(BUTTON_PIN);
+// This example uses the internal pull-up resistor in the Arduino
+ArduinoButton button(BUTTON_PIN, true);
 
 void setup() {
   Serial.begin(9600);
+  pinMode(BUTTON_PIN, INPUT_PULLUP);
   button.onKeyDown([]() {
     Serial.println("Button key down callback");
   });

examples/KeyUp/KeyUp.ino

@@ -1,11 +1,13 @@
-#include <ArduinoButton.h>
+#include "ArduinoButton.h"
 
-#define BUTTON_PIN 7
+#define BUTTON_PIN 6
 
-ArduinoButton button(BUTTON_PIN);
+// This example uses the internal pull-up resistor in the Arduino
+ArduinoButton button(BUTTON_PIN, true);
 
 void setup() {
   Serial.begin(9600);
+  pinMode(BUTTON_PIN, INPUT_PULLUP);
   button.onKeyUp([]() {
     Serial.println("Button key up callback");
   });