{ PIC32MX250F128B USB HID device with a button on RD0 and an LED on RD1       }

{ Copyright (C)2016-2024, Philip Munts dba Munts Technologies.                }
{                                                                             }
{ Redistribution and use in source and binary forms, with or without          }
{ modification, are permitted provided that the following conditions are met: }
{                                                                             }
{ * Redistributions of source code must retain the above copyright notice,    }
{   this list of conditions and the following disclaimer.                     }
{                                                                             }
{ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" }
{ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE   }
{ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE  }
{ ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE   }
{ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR         }
{ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF        }
{ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS    }
{ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN     }
{ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)     }
{ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE  }
{ POSSIBILITY OF SUCH DAMAGE.                                                 }

PROGRAM HID_Button_LED;

VAR
  readbuf   : ARRAY [HID_OUTPUT_REPORT_BYTES] OF byte;
  writebuf  : ARRAY [HID_INPUT_REPORT_BYTES] OF byte;
  Button  : sbit AT PORTA.b4;
  LED    : sbit AT LATB.b5;
  ButtonOld : boolean;
  ButtonNew : boolean;

  PROCEDURE USBInterrupt(); iv IVT_USB_1; ilevel 7; ics ICS_SOFT;

  BEGIN
    USB_Interrupt_Proc();
  END;

BEGIN
  ANSELA := $0000;
  ANSELB := $0000;

  { Configure button input }

  TRISA.b4 := 1;
  ButtonOld := NOT Button;

  { Configure LED output }

  TRISB.b5 := 0;
  LED := 0;

  { Initialize HID library }

  HID_Enable(@readbuf, @writebuf);

  { Configure USB interrupt }

  USBIP0_bit := 1;
  USBIP1_bit := 1;
  USBIP2_bit := 1;
  EnableInterrupts();

  { Main event loop }

  WHILE True DO
    BEGIN
      { Send a report to the USB host if the button changed state }

      ButtonNew := NOT Button;
      IF ButtonNew <> ButtonOld THEN
        BEGIN
          memset(@writebuf, 0, sizeof(writebuf));
          writebuf[0] := ButtonNew;
          HID_write(@writebuf, sizeof(writebuf));
          ButtonOld := ButtonNew;
        END;

      { Set LED state per command from the USB host }

      IF HID_read() <> 0 THEN
        BEGIN
          LED := readbuf[0];
        END;
    END;
END.