////                     16F877A_AD_to_rs232_LCD_i2c5.c                  ////
////                  read AtoD 0,1,2 and print values by rs232          ////
////     also print to LCD and send data to Slug when requested by i2c   ////
//---------------------------------------------------------------------------
//     program PIC_i2c sends a string of data bytes - these are:-
// 1 - 80 (decimal address of the PIC - Linux version)
// 2 - StartPoint  - save data starting at buf[StartPoint]
//            - - now send the data bytes - -
// 3 - Master sends value of x when requesting 2 byte AtoD value
// 4 - command byte - makes PIC change the display 0=main 1=admin
// 5 - bytes 5 to 7 are for future use
// 6
// 7
// 8
// eg ./PIC_i2c 80 0 0 0 0 0 0 0 - see admin page
//    ./PIC_i2c 80 0 0 1 0 0 0 0 - see temperatures as -2.5,12.5 etc
//--------------------------------------------------------------------------
// these are my settings in Flex_LCD420.c
//     #define LCD_DB4   PIN_B4
//     #define LCD_DB5   PIN_B5
//     #define LCD_DB6   PIN_B6
//     #define LCD_DB7   PIN_B7
//     #define LCD_RS    PIN_B3
//   //#define LCD_RW    PIN_B0 (this is earthed - no read from LCD)
//     #define LCD_E     PIN_B2
//--------------------------------------------------------------------------
//  PORTC.4 [RC4]   -> I2C SDA (I2C Serial Data)
//  PORTC.3 [RC3]   -> I2C SCL (I2C Serial Clock)
//  i2c address set here is 0xA0 - it becomes 0x50 (dec 80) on the Slug
// - Linux puts a 0 before the PIC address and removes one at the end
//--------------------------------------------------------------------------

#include <16F877A.h>
#device ADC=16
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#use i2c(SLAVE, SDA=PIN_C4, SCL=PIN_C3, address=0xA0, FORCE_HW) 
  //I2C by Hardware,i2c address (dec 80)is the first byte from the master
#include <Flex_LCD420.c> //the general purpose LCD display driver
BYTE incoming, state; // receive string of up to 127 bytes on the i2c line
BYTE StartPoint ; // Load data from master starting at buf[StartPoint]
                  //StartPoint is the second byte in the string from the master
int8 buf[8]={0,0,0,0,0,0,0,0}; //we could make this longer in future
 // the string of data bytes received from the master is stored in buf[]
 // starting at buf[StartPoint]. 
 // Prog PIC_i2c sends <i2c address> <StartPoint> <command> - then 5 bytes
 // that are stored at a location in the array buf[] starting at buf[StartPoint]
 // PIC_i2c could be modified to send up to 125 data bytes per run to master
int16  buffer[8];  //Array of 2 byte Int16s that are copies of the buf (int8) data 
int8 i;//for a count
int8 x;//used by master to count up the Val10Bit[] array
long value[8];//AtoD values from the PIC AtoD pins (values 0-65472)
long Val10Bit[8];// create a (0 to 1023) value from value[8]
float Temperature[8];//use for decimal representation of temperatures
int8 TempByte[8]={91,92,93,94,95,96,97,98}; 
      // data is stored here ready for sending to the master
      //0 is -10 degrees, 100 is 40 degrees (byte to send to Slug)
      //about 2 units on the A/D (0to1023) are equivalent to 1 degree C

//==============================================================i2c routine
#INT_SSP
void ssp_interupt ()
{
  state = i2c_isr_state();
  //i2c event caused by master interrups the PIC and state says
  //if the master is requesting or sending data
  if(state < 0x80) //Master is sending data
  {
     if(state == 0)
     {
     }       
             if(state == 1)  //First received byte is StartPoint
             {
               incoming = i2c_read();
               StartPoint = incoming;
             }      
     for(i=0; i<=8; ++i) //(start at 2, 125 vaues maximum)
      {
      if(state == (i+2))  // state increments as each data byte  comes in
        {
          incoming = i2c_read();
          buf[StartPoint+i] = incoming;
          buffer[StartPoint+i] = (long)buf[StartPoint+i]; //int16 needed later
        }
      }
  }
  
  if(state == 0x80)  //Master is requesting data from the PIC
  {
   x = buf[StartPoint]; //send the temperature asked for
 //  The first byte from the master (stored at buf[StartPoint]) increments
 // on each of master's repeated request for data and forces the PIC to scan up
 // the TempByte[] array and send to master the byte stored there
 
for(i=0; i<=6; i=i+2) //send master AtoD long values as LO byte then HI byte
{
if (x==i)
  {
   i2c_write (Val10Bit[i/2]);
  }
if (x==i+1)
  {
   i2c_write (Val10Bit[i/2]>>8);//bit shift HI byte to LO byte position
  }
}

if (x>=6)
  {
   i2c_write (99);//change later
  }
//------------------------
}
}

//====================================================================main
void main() 
{
   int8 i;
   lcd_init();
  enable_interrupts(INT_SSP);
  enable_interrupts(GLOBAL);

   delay_ms(200); // power up delay
   
     printf(lcd_putc, "\f"); //clear screen
     delay_ms(500);
     lcd_putc("\fWelcome! . . .\n");  // first display
     delay_ms(2000);
     
   setup_port_a( ALL_ANALOG );
   setup_adc( ADC_CLOCK_INTERNAL );
   
   do {
         for(i=0; i<=2; ++i) //read PIC AtoD lines 0,1 and 2
         {
         set_adc_channel( i );
         delay_ms(100);
         value[i] = Read_ADC(); //comes in as 0-65472
             Val10Bit[i] = value[i]/64; // value now  0-1023
             //master is sent 0 to 100 meaning -10 to +40 degrees
             if (Val10Bit[i]>=640) //-10 to +40 degrees  is 540 to 640 approx
             TempByte[i] = 100; //we send this temperature byte to the Slug
               if (Val10Bit[i]<=540)
               TempByte[i] = 0;
                 if ((Val10Bit[i] > 540) && (Val10Bit[i] < 640))
                 TempByte[i] = Val10Bit[i] - 540;
                 Temperature[i] = TempByte[i];
                 Temperature[i] = Temperature[i] - 20;
                 Temperature[i] = Temperature[i]/2;
          }
      
         
      //==========================================================rs232 display
// un-comment next line to get a report on the rs232 port
// printf("Value 0: %Lu  Value 1: %Lu  Value 2: %Lu\n\r",(value[0]/64), (value[1]/64), (value[2]/64));
   
      //============================================================LCD display
   printf(lcd_putc, "\f");//clear screen
     delay_ms(5);

    //buf[StartPoint + 1] is the command byte from the master
   if(buf[StartPoint + 1] == 0)
   {
           for(i=0; i<=2; ++i) //print raw AtoD values
           {
           lcd_gotoxy((1+5*i),1);
            printf(lcd_putc, "%Lu ", Val10Bit[i]);
           }
    lcd_gotoxy(1,2);
      printf(lcd_putc, "0=%u  1=%u 2=%u ", TempByte[0],TempByte[1],TempByte[2]);
    lcd_gotoxy(1,3);  
    printf(lcd_putc, "StPt %u x %u Cmd %u", StartPoint, buf[StartPoint], buf[StartPoint+1]);
           for(i=0; i<=3; ++i) //print raw AtoD values
           {
           lcd_gotoxy((1+4*i),4);
            printf(lcd_putc, "%u ", buf[StartPoint+2+i]);
           }
      delay_ms(100);
   }
   if(buf[StartPoint + 1] == 1)
   {
    lcd_gotoxy(1,2);
      printf(lcd_putc, "Temperature 0 %2.1g",Temperature[0]) ;
    lcd_gotoxy(1,3);  
     printf(lcd_putc, "Temperature 1 %2.1g",Temperature[1]) ;
    lcd_gotoxy(1,4);       
    printf(lcd_putc, "Temperature 2 %2.1g",Temperature[2] );
      delay_ms(100);
   }
   if(buf[StartPoint + 1] >= 2)
   {
    lcd_gotoxy(1,2);
      printf(lcd_putc, "invalid command");
   }

      } while (TRUE);

}