#include <16F688.h>
#device *=16
#device adc=8
#fuses NOWDT,INTRC_IO, NOPROTECT, NOBROWNOUT, MCLR, NOCPD, PUT, NOIESO, FCMEN
#use delay(clock=8000000)
#use rs232(baud=9600,parity=N,xmit=PIN_C4,rcv=PIN_C5,bits=8)


#use fast_io(A)
#use fast_io(C)

//Registers and bits used for serial comms
#bit        CREN   = 0x17.4                 // RCSTA Habilitación de recepción continua 1 ==> Habilitado
#bit        OERR   = 0x17.1                 // RCSTA     1 ==> Error de sobreflujo
#byte       RCREG  = 0x14
#bit        RCIF   = 0x0C.5                 //PIR1

//Inputs and outputs definition
#define  InRD              PIN_C0
#define  InWR              PIN_C1

#define  OutRdy            PIN_A0
#define  OutOK             PIN_A1
#define  OutRst            PIN_A2

//Station Indentifier definition modify to acomadate your station
#define  StID_Espected     0x03
#define  StID_ToWrite      0x45

//Subrrutine declaration, implementation is at the bottom
void Configuration(void);
unsigned int ReadByte(void);
void WriteByte(unsigned int);
void ResetCommand(void);
void ReadCommand(void);
void WriteCommand(void);

/*---------------------------------------------------------------------------------------------------------------
                  MAIN PROGRAM STARTS
----------------------------------------------------------------------------------------------------------------*/
void main()
{
   Configuration();

   // Start main cycle
   while(TRUE)
   {
      //if both inputs RD and WR are 1, then reset the HMS830 RFID system
      if(input(InWR) && input(InRD))
         {
            ResetCommand();
         }

      //Trigger the Read Command
      if(input(InRD) && !input(InWR))
         {
            delay_ms(100);
            if(input(InRD) && !input(InWR))
              {
               ReadCommand();
              }
         }

      //Trigger Write Commad
      if(input(InWR) && !input(InRD))
         {
            delay_ms(100);
            if(input(InWR) && !input(InRD))
              {
               WriteCommand();
              }
         }
   }//End Main Cycle
}//End Main Program


/*---------------------------------------------------------------------------------------------------------------------
      SUBRUTINES IMPLEMENTATION
----------------------------------------------------------------------------------------------------------------------*/

void Configuration(void)
{
   setup_adc_ports(NO_ANALOGS|VSS_VDD);
   setup_adc(ADC_OFF);
   setup_timer_0(RTCC_INTERNAL);
   setup_wdt(WDT_DIV_65536);
   setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);
   setup_timer_2(T2_DISABLED,0,1);
   setup_comparator(NC_NC_NC_NC);
   setup_vref(FALSE);

   set_tris_A(0b11111000);
   set_tris_C(0b11100111);

   output_high(OutRdy);
   delay_ms(1000);
   output_low(OutRdy);
   delay_ms(1000);
   output_high(OutOK);
   delay_ms(1000);
   output_low(OutOK);
   delay_ms(1000);
   output_low(OutRst);
}

//Configuration subrrutine
void ResetCommand(void)
{
   delay_ms(100);
   if(input(InWR) && input(InRD))
     {
         output_high(OutRst);
         delay_ms(500);
         output_low(OutRst);
     }
   while(input(InWR) && input(InRD));
}

//Subrutine to write a single byte to serial port
void WriteByte(unsigned int c)
 {
   putc(c);
 }

//Subrrutine to read a single byte from serial port
unsigned int ReadByte(void)
{
      unsigned long ContEsp = 0;
      char  c;

   while((ContEsp < 65534) && !RCIF)
      {
         ContEsp++;
         delay_cycles(1);
      }
   if (OERR)
      {
         CREN = 0;
         delay_cycles(1);
         CREN = 1;
      }
   c = RCREG;
   return(c);
}

//Performs a Read Block Command and checks for the correct Station ID
void ReadCommand(void)
{
 unsigned int8 Retransmit = 0;
 int1 StID_IsOK = FALSE;
 unsigned int8 Data,CommandEcho,TimeCounter;

 do{
   WriteByte(0x02); //Header
   WriteByte(0x02); //Header
   WriteByte(0x00); //Command Size
   WriteByte(0x07); //Command Size
   WriteByte(0x05); //Command
   WriteByte(0x00); //Start Address
   WriteByte(0x03); //Start Address
   WriteByte(0x00); //Block Size
   WriteByte(0x01); //Block Size
   WriteByte(0x01); //Time Out 500ms
   WriteByte(0xF4); //Time Out 500ms
   WriteByte(0x03); //Terminator

   Data = 0;
   CommandEcho = 0;
   TimeCounter = 0;
   set_timer1(0);
   //Wait for a response from HMS830
   do{
      if(get_timer1() > 60000)
        {
         TimeCounter++;
         set_timer1(0);
        }
   }while((TimeCounter <= 5) && !RCIF);

   if(RCIF)
     {
                    ReadByte();//STX
                    ReadByte();//STX
                    ReadByte();//Response Size
                    ReadByte();//Response Size
      CommandEcho = ReadByte();//Command Echo
      Data        = ReadByte();//Data
                    ReadByte();//Checksum
                    ReadByte();//Terminator

      if((CommandEcho == 5) && ((Data == StID_Espected) || (Data == StID_ToWrite)))
        {
         StID_IsOK = TRUE;
        }
      else
        {
         Retransmit++;
         delay_ms(200);
        }
     }
    else
     {
      Retransmit++;
      delay_ms(200);
     }
 }while(!StID_IsOK && (Retransmit<3));//End retrasnmit

 if(StID_IsOK)
   {
      output_high(OutOK);
      delay_ms(20);
      output_high(OutRdy);
   }
 else
   {
    output_high(OutRdy);
   }

 while(input(InRD) || input(InWR));

 output_low(OutOK);
 output_low(OutRdy);
}//EndReadCommand

/*----------------------------------------------------------------------------------------------------------*/
//Performs the Station ID writing
void WriteCommand(void)
{
 unsigned int8 Retransmit = 0;
 unsigned int8 Data,CommandEcho,TimeCounter;
 int1 CmdOK = FALSE;
 do{
   WriteByte(0x02); //Header
   WriteByte(0x02); //Header
   WriteByte(0x00); //Command Size
   WriteByte(0x08); //Command Size
   WriteByte(0x06); //Command
   WriteByte(0x00); //Start Address
   WriteByte(0x03); //Start Address
   WriteByte(0x00); //Block Size
   WriteByte(0x01); //Block Size
   WriteByte(0x01); //Time Out 500ms
   WriteByte(0xF4); //Time Out 500ms
   WriteByte(StID_ToWrite); //Data
   WriteByte(0x03); //Terminator

   Data = 0;
   CommandEcho = 0;
   TimeCounter = 0;
   set_timer1(0);
   //Waits for a response from HMS830
   do{
      if(get_timer1() > 60000)
        {
         TimeCounter++;
         set_timer1(0);
        }
   }while((TimeCounter <= 5) && !RCIF);

   if(RCIF)
     {
                    ReadByte();//STX
                    ReadByte();//STX
                    ReadByte();//Response Size
                    ReadByte();//Response Size
      CommandEcho = ReadByte();//Command Echo
      if(CommandEcho != 6)
      {
       Data        = ReadByte();//Error ID
      }
                    ReadByte();//Checksum
                    ReadByte();//Terminator

      if(CommandEcho == 6)
        {
         CmdOK = TRUE;
        }
      else
        {
         Retransmit++;
         delay_ms(200);
        }

     }
    else
     {
      Retransmit++;
      delay_ms(200);
     }
 }while(!CmdOK && (Retransmit<3));//End retrasnmit

 if(CmdOK)
   {
      output_high(OutOK);
      delay_ms(20);
      output_high(OutRdy);
   }
 else
   {
    output_high(OutRdy);
   }

 while(input(InRD) || input(InWR));

 output_low(OutOK);
 output_low(OutRdy);
}//EndWriteCommand