Feature Addition: Buttons can be active high or low

examples/button/button.ino

@@ -19,7 +19,7 @@ void setup() {
     .onInput( led3, led3.EVT_TOGGLE_BLINK );
 
   // Button triggers the fan
-  btn.begin( 2 ) 
+  btn.begin( 2 , LOW) 
     .onPress( fan, fan.EVT_INPUT );
 
   // Start the blinking
@@ -31,4 +31,4 @@ void setup() {
 
 void loop() {
   automaton.run();
-}
+}

examples/frere_jacques/frere_jacques.ino

@@ -23,7 +23,7 @@ void setup() {
     .play( pattern, sizeof( pattern ) )
     .repeat( -1 );
 
-  button.begin( 2 ) // A button on pin 2 toggles playback on and off
+  button.begin( 2 , LOW) // A button on pin 2 toggles playback on and off
     .onPress( player, player.EVT_TOGGLE );
 
   speed.begin( A0 ) // An analog pot on pin A0 controls playback speed

examples/knight_rider2/knight_rider2.ino

@@ -10,7 +10,7 @@ void setup() {
     .speed( 50 ) 
     .trigger( sweep.EVT_START );
 
-  button.begin( 2 )
+  button.begin( 2 , LOW)
     .onPress( sweep, sweep.EVT_TOGGLE );
 
 }

examples/led_test/led_test.ino

@@ -16,10 +16,10 @@ void setup() {
   led.begin( ledPin )
     .blink( 1000 ); 
 
-  button.begin( buttonPin )
+  button.begin( buttonPin , LOW)
     .onPress( led, led.EVT_TOGGLE );
 }
 
 void loop() {
   automaton.run();
-}
+}

examples/nuclear_missile_launcher/nuclear_missile_launcher.ino

@@ -19,7 +19,7 @@ const int countdownFlashOff = 900;
 
 void setup() {
   // Self resetting button 1
-  button1.begin( pinButton1 )
+  button1.begin( pinButton1 , LOW)
     .onPress( bit1, bit1.EVT_ON );
 
   timer1.begin( buttonIntervalMax )
@@ -29,7 +29,7 @@ void setup() {
     .onChange( true, timer1, timer1.EVT_START );
 
   // Self resetting button 2
-  button2.begin( pinButton2 )
+  button2.begin( pinButton2 , LOW)
     .onPress( bit2, bit2.EVT_ON );
 
   timer2.begin( buttonIntervalMax )

src/Atm_button.cpp

@@ -2,7 +2,7 @@
 
 // Add option for button press callback (for reading i2c buttons etc)
 
-Atm_button& Atm_button::begin( int attached_pin ) {
+Atm_button& Atm_button::begin( int attached_pin, int _active_high ) {
   // clang-format off
   const static state_t state_table[] PROGMEM = {
     /* Standard Mode: press/repeat */
@@ -23,12 +23,17 @@ Atm_button& Atm_button::begin( int attached_pin ) {
   // clang-format on
   Machine::begin( state_table, ELSE );
   pin = attached_pin;
+  active_high = _active_high;
   counter_longpress.set( 0 );
   timer_debounce.set( DEBOUNCE );
   timer_delay.set( ATM_TIMER_OFF );
   timer_repeat.set( ATM_TIMER_OFF );
   timer_auto.set( ATM_TIMER_OFF );
-  pinMode( pin, INPUT_PULLUP );
+  if (active_high) {
+    pinMode( pin, INPUT_PULLUP );
+  } else {
+    pinMode( pin, INPUT_PULLDOWN );
+  }
   return *this;
 }
 
@@ -45,9 +50,9 @@ int Atm_button::event( int id ) {
     case EVT_AUTO:
       return timer_auto.expired( this );
     case EVT_PRESS:
-      return !digitalRead( pin );
+      return digitalRead( pin ) == active_high;
     case EVT_RELEASE:
-      return digitalRead( pin );
+      return digitalRead( pin ) != active_high;
     case EVT_COUNTER:
       return counter_longpress.expired();
   }

src/Atm_button.hpp

@@ -9,7 +9,7 @@ class Atm_button : public Machine {
   enum { BTN_PASS4 = -4, BTN_PASS3 = -3, BTN_PASS2 = -2, BTN_PASS1 = -1, BTN_RELEASE = 0, BTN_PRESS1 = 1, BTN_PRESS2 = 2, BTN_PRESS3 = 3, BTN_PRESS4 = 4 };
 
   Atm_button( void ) : Machine(){};
-  Atm_button& begin( int attached_pin );
+  Atm_button& begin( int attached_pin, int _active_high );
   Atm_button& trace( Stream& stream );
   Atm_button& onPress( atm_cb_push_t callback, int idx = 0 );
   Atm_button& onPress( Machine& machine, int event = 0 );
@@ -28,6 +28,7 @@ class Atm_button : public Machine {
   atm_connector onpress, onrelease;
   atm_connector longpress[2];
   short pin;
+  short active_high;
   atm_timer_millis timer_debounce, timer_delay, timer_repeat, timer_auto;
   atm_counter counter_longpress;
   int longpress_max;

src/atm_timer_millis.cpp

@@ -18,6 +18,15 @@ void atm_timer_millis::setFromNow( Machine* machine, uint32_t v ) {
   value = millis() - machine->state_millis + v;
 }
 
+/*
+ * atm_timer_millis::elapsed( this ) - returns the elapsed time so far
+ * This is a rollover-safe 32 bit unsigned integer
+ *
+ */
+uint32_t atm_timer_millis::elapsed( Machine* machine ) {
+    return value == ATM_TIMER_OFF ? 0 : millis() - machine->state_millis;
+}
+
 /*
  * atm_timer_millis::expired( this ) - Checks a millis timer for expiry (== 0)
  * This is a rollover-safe 32 bit unsigned integer comparison

src/atm_timer_millis.hpp

@@ -12,5 +12,6 @@ class atm_timer_millis {
   uint32_t value;
   void set( uint32_t v );
   void setFromNow( Machine* machine, uint32_t v );
+  uint32_t elapsed( Machine* machine );
   int expired( Machine* machine );
 };