More user-button interrupt handler testing

eRINA_STM32F7/src/rina/board.adb

@@ -1,11 +1,74 @@
 with Debug;
+with STM32.Board;  use STM32.Board;
+with STM32.Device; use STM32.Device;
+with STM32.GPIO;   use STM32.GPIO;
+with STM32.EXTI;   use STM32.EXTI;
 
 package body Board is
+
+   Button_High : Boolean := True;
+
+   Debounce_Time : constant Time_Span := Milliseconds (250);
+
+   EXTI_Line : constant External_Line_Number :=
+     User_Button_Point.Interrupt_Line_Number;
+
+   Initialization_Complete : Boolean := False;
+
    protected body Button_Handler is
-      procedure Pressed is
+      procedure Interrupt is
+      begin
+         Clear_External_Interrupt (EXTI_Line);
+         Debug.Print (Debug.Info, "Button pressed!");
+         if (Button_High and then User_Button_Point.Set)
+           or else (not Button_High and then not User_Button_Point.Set)
+         then
+            if Clock - Start_Time > Debounce_Time then
+               Pressed := True;
+            end if;
+         end if;
+      end Interrupt;
+
+      function Current_State return Boolean is
+      begin
+         return Pressed;
+      end Current_State;
+
+      procedure Clear_State is
       begin
-         STM32.Board.All_LEDs_On;
-         Debug.Print(Debug.Info, "Button pressed!");
-      end Pressed;
+         if Pressed then
+            Start_Time := Clock;
+            Pressed    := False;
+         end if;
+      end Clear_State;
    end Button_Handler;
-end Board;
+
+   procedure Initialize (Use_Rising_Edge : Boolean := True) is
+      Edge : constant External_Triggers :=
+        (if Use_Rising_Edge then Interrupt_Rising_Edge
+         else Interrupt_Falling_Edge);
+   begin
+      Enable_Clock (User_Button_Point);
+
+      User_Button_Point.Configure_IO
+        ((Mode      => Mode_In,
+          Resistors => (if Use_Rising_Edge then Pull_Down else Pull_Up)));
+
+      --  Connect the button's pin to the External Interrupt Handler
+      User_Button_Point.Configure_Trigger (Edge, 0);
+
+      Button_High             := Use_Rising_Edge;
+      Initialization_Complete := True;
+   end Initialize;
+
+   function Has_Been_Pressed return Boolean is
+      State : Boolean;
+   begin
+      State := Button_Handler.Current_State;
+      Button_Handler.Clear_State;
+
+      return State;
+   end Has_Been_Pressed;
+
+   function Initialized return Boolean is (Initialization_Complete);
+end Board;

eRINA_STM32F7/src/rina/board.ads

@@ -1,9 +1,28 @@
 with STM32;
 with STM32.Board;
+with Ada.Real_Time; use Ada.Real_Time;
 
 package Board is
-   protected type Button_Handler is
-      procedure Pressed;
-      pragma Attach_Handler (Pressed, STM32.Board.User_Button_Interrupt);
+
+   procedure Initialize (Use_Rising_Edge : Boolean := True) with
+     Pre => not Initialized, Post => Initialized;
+
+   function Has_Been_Pressed return Boolean with
+     Pre => Initialized;
+   --  Returns whether the user button has been pressed since the last time
+   --  this subprogram was called.
+
+   function Initialized return Boolean;
+
+   protected Button_Handler is
+      pragma Interrupt_Priority;
+      function Current_State return Boolean;
+      procedure Clear_State;
+   private
+      procedure Interrupt;
+      pragma Attach_Handler (Interrupt, STM32.Board.User_Button_Interrupt);
+
+      Pressed    : Boolean := False;
+      Start_Time : Time    := Clock;
    end Button_Handler;
-end Board;
+end Board;