sbit SoftSpi_CLK at RA0_bit;
sbit SoftSpi_SDI at RA1_bit;
sbit SoftSpi_SDO at RA2_bit;
sbit SoftSpi_CLK_Direction at TRISA0_bit;
sbit SoftSpi_SDI_Direction at TRISA1_bit;
sbit SoftSpi_SDO_Direction at TRISA2_bit;

sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;
sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;

unsigned short value;
unsigned short read;
char uart_rd;
char broj[10];
char niza[16];
int counter;
int i;
short shouldBreak = 0;
short oneDollar = 0;
int temp;
int zbir;

void printOnScreen(){
     Lcd_Cmd(_LCD_CLEAR);
     temp = 16 - counter;
     for (i = 1; i <= temp;i++){
     Lcd_Chr(1,i,' ');
     }
     for(i = temp + 1; i <= 16; i++){
     Lcd_Chr(i,i,niza[i - temp - 1]);
     }

      Delay_ms(1);
}
void sendBySPI(){
     char* zbirot;

     IntToStr(zbir,broj);



     zbirot = Ltrim(broj);
     Lcd_Cmd(_LCD_CLEAR);
     Lcd_Out(1,1,"Prakjam zbir");
     Lcd_Out(2,1,zbirot);
     Delay_ms(5);

     if (zbir > 10){
       if (zbir > 99){
           Soft_SPI_Write(broj[7]);
           Soft_SPI_Write(broj[8]);
           Soft_SPI_Write(broj[9]);
       }
       else{
           Soft_SPI_Write(broj[8]);
           Soft_SPI_Write(broj[9]);
       }
     }else{
           Soft_SPI_Write(broj[9]);
     }



}

void printError(){
     Lcd_Cmd(_LCD_CLEAR);
     Lcd_Out(1,1,Ltrim("Error!"));
           Delay_ms(1);
}

void printEnd(){
     Lcd_Cmd(_LCD_CLEAR);
     Lcd_Out(1,1,Ltrim("End"));
}

void main() {

     ANSEL  = 0;
     ANSELH = 0;

     C1ON_bit = 0;
     C2ON_bit = 0;

     Soft_SPI_Init();
     UART1_Init(9600);
     Lcd_Init();
     Lcd_Cmd(_LCD_CURSOR_OFF);
     Lcd_Cmd(_LCD_CLEAR);
     Delay_ms(5);

     counter = 0;
     zbir = 0;
     while(1){

              if (UART1_Data_Ready()) {
                 uart_rd = UART1_Read();
                 Lcd_Cmd(_LCD_CLEAR);
                 Lcd_Chr(1,1,uart_rd);
                 Delay_ms(1);

                 if (uart_rd >= '0' && uart_rd <= '9'){
                      if (counter == 16){
                        printError();
                        oneDollar = 0;
                        counter = 0;
                        for (i = 0; i < 16; i++){
                              niza[i] = ' ';
                        }
                      }else{
                        niza[counter] = uart_rd;
                        zbir = zbir + (uart_rd - '0');

                        counter = counter + 1;
                        intToStr(counter,broj);
                        Lcd_Out(2,1,"C: ");
                        Lcd_Out(2,4,broj);
                        delay_ms(1);
                        oneDollar = 0;
                      }
                 }else if (uart_rd == '$'){
                       if (oneDollar){
                          printEnd();
                          shouldBreak = 1;
                       }else{
                          oneDollar = 1;
                          printOnScreen();
                          sendBySPI();
                          counter = 0;
                          zbir = 0;

                          for (i = 0; i < 16; i++){
                              niza[i] = ' ';
                          }
                        }
                 }else{
                      printError();
                      oneDollar = 0;
                      counter = 0;
                      zbir = 0;
                      for (i = 0; i < 16; i++){
                              niza[i] = ' ';
                      }
                 }
              }

              if (shouldBreak){
              break;
              }
     }
}