Instantiate just one copy of Button in Plane and Copter

ArduCopter/Copter.cpp

@@ -199,7 +199,7 @@ const AP_Scheduler::Task Copter::scheduler_tasks[] = {
     SCHED_TASK(userhook_SuperSlowLoop, 1,   75),
 #endif
 #if BUTTON_ENABLED == ENABLED
-    SCHED_TASK_CLASS(AP_Button,            &copter.g2.button,           update,           5, 100),
+    SCHED_TASK_CLASS(AP_Button,            &copter.button,           update,           5, 100),
 #endif
 #if STATS_ENABLED == ENABLED
     SCHED_TASK_CLASS(AP_Stats,             &copter.g2.stats,            update,           1, 100),

ArduCopter/Copter.h

@@ -531,11 +531,6 @@ class Copter : public AP_Vehicle {
     AP_Parachute parachute{relay};
 #endif
 
-    // Button 
-#if BUTTON_ENABLED == ENABLED
-    AP_Button button;
-#endif
-
     // Landing Gear Controller
     AP_LandingGear landinggear;
 

ArduCopter/Parameters.cpp

@@ -735,7 +735,7 @@ const AP_Param::GroupInfo ParametersG2::var_info[] = {
 #if BUTTON_ENABLED == ENABLED
     // @Group: BTN_
     // @Path: ../libraries/AP_Button/AP_Button.cpp
-    AP_SUBGROUPINFO(button, "BTN_", 2, ParametersG2, AP_Button),
+    AP_SUBGROUPPTR(button_ptr, "BTN_", 2, ParametersG2, AP_Button),
 #endif
 
 #if MODE_THROW_ENABLED == ENABLED
@@ -1052,6 +1052,7 @@ ParametersG2::ParametersG2(void)
 #if MODE_AUTOROTATE_ENABLED == ENABLED
     ,arot(copter.inertial_nav)
 #endif
+    ,button_ptr(&copter.button)
 {
     AP_Param::setup_object_defaults(this, var_info);
 }

ArduCopter/Parameters.h

@@ -485,10 +485,8 @@ class ParametersG2 {
     // altitude at which nav control can start in takeoff
     AP_Float wp_navalt_min;
 
-#if BUTTON_ENABLED == ENABLED
     // button checking
-    AP_Button button;
-#endif
+    AP_Button *button_ptr;
 
 #if STATS_ENABLED == ENABLED
     // vehicle statistics

ArduPlane/ArduPlane.cpp

@@ -93,7 +93,7 @@ const AP_Scheduler::Task Plane::scheduler_tasks[] = {
     SCHED_TASK_CLASS(AP_InertialSensor, &plane.ins, periodic, 50, 50),
     SCHED_TASK(avoidance_adsb_update,  10,    100),
     SCHED_TASK_CLASS(RC_Channels,       (RC_Channels*)&plane.g2.rc_channels, read_aux_all,           10,    200),
-    SCHED_TASK_CLASS(AP_Button, &plane.g2.button, update, 5, 100),
+    SCHED_TASK_CLASS(AP_Button, &plane.button, update, 5, 100),
 #if STATS_ENABLED == ENABLED
     SCHED_TASK_CLASS(AP_Stats, &plane.g2.stats, update, 1, 100),
 #endif

ArduPlane/Parameters.cpp

@@ -1104,7 +1104,7 @@ const AP_Param::GroupInfo ParametersG2::var_info[] = {
 
     // @Group: BTN_
     // @Path: ../libraries/AP_Button/AP_Button.cpp
-    AP_SUBGROUPINFO(button, "BTN_", 1, ParametersG2, AP_Button),
+    AP_SUBGROUPPTR(button_ptr, "BTN_", 1, ParametersG2, AP_Button),
 
     // @Group: ICE_
     // @Path: ../libraries/AP_ICEngine/AP_ICEngine.cpp
@@ -1253,6 +1253,7 @@ ParametersG2::ParametersG2(void) :
 #if SOARING_ENABLED == ENABLED
     ,soaring_controller(plane.ahrs, plane.TECS_controller, plane.aparm)
 #endif
+    ,button_ptr(&plane.button)
 {
     AP_Param::setup_object_defaults(this, var_info);
 }

ArduPlane/Parameters.h

@@ -505,7 +505,7 @@ class ParametersG2 {
     static const struct AP_Param::GroupInfo var_info[];
 
     // button reporting library
-    AP_Button button;
+    AP_Button *button_ptr;
 
 #if STATS_ENABLED == ENABLED
     // vehicle statistics

Tools/autotest/apmrover2.py

@@ -981,44 +981,6 @@ def test_sysid_enforce(self):
         if ex is not None:
             raise ex
 
-    def drain_mav_seconds(self, seconds):
-        tstart = self.get_sim_time_cached()
-        while self.get_sim_time_cached() - tstart < seconds:
-            self.drain_mav();
-            self.delay_sim_time(0.5)
-
-    def test_button(self):
-        self.set_parameter("SIM_PIN_MASK", 0)
-        self.set_parameter("BTN_ENABLE", 1)
-        btn = 2
-        pin = 3
-        self.drain_mav()
-        self.set_parameter("BTN_PIN%u" % btn, pin)
-        m = self.mav.recv_match(type='BUTTON_CHANGE', blocking=True, timeout=1)
-        self.progress("m: %s" % str(m))
-        if m is None:
-            raise NotAchievedException("Did not get BUTTON_CHANGE event")
-        mask = 1<<btn
-        if m.state & mask:
-            raise NotAchievedException("Bit incorrectly set in mask (got=%u dontwant=%u)" % (m.state, mask))
-        # SITL instantly reverts the pin to its old value
-        m2 = self.mav.recv_match(type='BUTTON_CHANGE', blocking=True, timeout=1)
-        self.progress("m2: %s" % str(m2))
-        if m2 is None:
-            raise NotAchievedException("Did not get repeat message")
-        # wait for messages to stop coming:
-        self.drain_mav_seconds(15)
-
-        self.set_parameter("SIM_PIN_MASK", 0)
-        m3 = self.mav.recv_match(type='BUTTON_CHANGE', blocking=True, timeout=1)
-        self.progress("m3: %s" % str(m3))
-        if m3 is None:
-            raise NotAchievedException("Did not get new message")
-        if m.last_change_ms == m3.last_change_ms:
-            raise NotAchievedException("last_change_ms same as first message")
-        if m3.state != 0:
-            raise NotAchievedException("Didn't get expected mask back in message (mask=0 state=%u" % (m3.state))
-
     def test_rally_points(self):
         self.reboot_sitl() # to ensure starting point is as expected
 

Tools/autotest/arducopter.py

@@ -4282,6 +4282,10 @@ def tests(self):
              "Test Camera/Antenna Mount",
              self.test_mount),
 
+            ("Button",
+             "Test Buttons",
+             self.test_button),
+
             ("RangeFinder",
              "Test RangeFinder Basic Functionality",
              self.test_rangefinder),

Tools/autotest/arduplane.py

@@ -1638,6 +1638,10 @@ def tests(self):
              "Test ADSB",
              self.test_adsb),
 
+            ("Button",
+             "Test Buttons",
+             self.test_button),
+
             ("AdvancedFailsafe",
              "Test Advanced Failsafe",
              self.test_advanced_failsafe),

Tools/autotest/common.py

@@ -3590,6 +3590,44 @@ def test_advanced_failsafe(self):
         if ex is not None:
             raise ex
 
+    def drain_mav_seconds(self, seconds):
+        tstart = self.get_sim_time_cached()
+        while self.get_sim_time_cached() - tstart < seconds:
+            self.drain_mav();
+            self.delay_sim_time(0.5)
+
+    def test_button(self):
+        self.set_parameter("SIM_PIN_MASK", 0)
+        self.set_parameter("BTN_ENABLE", 1)
+        btn = 2
+        pin = 3
+        self.drain_mav()
+        self.set_parameter("BTN_PIN%u" % btn, pin)
+        m = self.mav.recv_match(type='BUTTON_CHANGE', blocking=True, timeout=1)
+        self.progress("m: %s" % str(m))
+        if m is None:
+            raise NotAchievedException("Did not get BUTTON_CHANGE event")
+        mask = 1<<btn
+        if m.state & mask:
+            raise NotAchievedException("Bit incorrectly set in mask (got=%u dontwant=%u)" % (m.state, mask))
+        # SITL instantly reverts the pin to its old value
+        m2 = self.mav.recv_match(type='BUTTON_CHANGE', blocking=True, timeout=1)
+        self.progress("m2: %s" % str(m2))
+        if m2 is None:
+            raise NotAchievedException("Did not get repeat message")
+        # wait for messages to stop coming:
+        self.drain_mav_seconds(15)
+
+        self.set_parameter("SIM_PIN_MASK", 0)
+        m3 = self.mav.recv_match(type='BUTTON_CHANGE', blocking=True, timeout=1)
+        self.progress("m3: %s" % str(m3))
+        if m3 is None:
+            raise NotAchievedException("Did not get new message")
+        if m.last_change_ms == m3.last_change_ms:
+            raise NotAchievedException("last_change_ms same as first message")
+        if m3.state != 0:
+            raise NotAchievedException("Didn't get expected mask back in message (mask=0 state=%u" % (m3.state))
+
     def tests(self):
         return [
             ("PIDTuning",

libraries/AP_Button/AP_Button.cpp

@@ -20,6 +20,8 @@
 
 extern const AP_HAL::HAL& hal;
 
+AP_Button *AP_Button::_singleton;
+
 const AP_Param::GroupInfo AP_Button::var_info[] = {
 
     // @Param: ENABLE
@@ -72,6 +74,11 @@ const AP_Param::GroupInfo AP_Button::var_info[] = {
 AP_Button::AP_Button(void)
 {
     AP_Param::setup_object_defaults(this, var_info);
+
+    if (_singleton != nullptr) {
+        AP_HAL::panic("AP_Button must be singleton");
+    }
+    _singleton = this;
 }
 
 /*
@@ -166,3 +173,12 @@ void AP_Button::setup_pins(void)
         hal.gpio->write(pin[i], 1);
     }
 }
+
+namespace AP {
+
+AP_Button &button()
+{
+    return *AP_Button::get_singleton();
+}
+
+}

libraries/AP_Button/AP_Button.h

@@ -28,12 +28,23 @@ class AP_Button {
     // constructor
     AP_Button(void);
 
+    /* Do not allow copies */
+    AP_Button(const AP_Button &other) = delete;
+    AP_Button &operator=(const AP_Button&) = delete;
+
     static const struct AP_Param::GroupInfo var_info[];
 
     // update button state and send messages, called periodically by main loop
     void update(void);
-
+
+    static AP_Button *get_singleton(void) {
+        return _singleton;
+    }
+
 private:
+
+    static AP_Button *_singleton;
+
     AP_Int8 enable;
     AP_Int8 pin[AP_BUTTON_NUM_PINS];
 
@@ -65,3 +76,6 @@ class AP_Button {
     void setup_pins();
 };
 
+namespace AP {
+    AP_Button &button();
+};