serial.h

Serial Port With Rs485 Driver For Atmel AVR

#define RXB8 1
#define TXB8 0
#define UPE 2
#define OVR 3
#define FE 4
#define UDRE 5
#define RXC 7

#define FRAMING_ERROR (1<<FE)
#define PARITY_ERROR (1<<UPE)
#define DATA_OVERRUN (1<<OVR)
#define DATA_REGISTER_EMPTY (1<<UDRE)
#define RX_COMPLETE (1<<RXC)

#define DIR PORTD.7
void Send_to_CPU(unsigned char Commond,unsigned char Data);

// USART Receiver buffer
#define RX_BUFFER_SIZE 8
char rx_buffer[RX_BUFFER_SIZE];

#if RX_BUFFER_SIZE<256
unsigned char rx_wr_index,rx_rd_index,rx_counter;
#else
unsigned int rx_wr_index,rx_rd_index,rx_counter;
#endif

// This flag is set on USART Receiver buffer overflow
bit rx_buffer_overflow;

// USART Receiver interrupt service routine
interrupt [USART_RXC] void usart_rx_isr(void)
{
char status,data;
status=UCSRA;
data=UDR;
if ((status & (FRAMING_ERROR | PARITY_ERROR | DATA_OVERRUN))==0)
   {
   rx_buffer[rx_wr_index]=data;
   if (++rx_wr_index == RX_BUFFER_SIZE) rx_wr_index=0;
   if (++rx_counter == RX_BUFFER_SIZE)
      {
      rx_counter=0;
      rx_buffer_overflow=1;
      };
   };
}

#ifndef _DEBUG_TERMINAL_IO_
// Get a character from the USART Receiver buffer
#define _ALTERNATE_GETCHAR_
#pragma used+
char getchar(void)
{
char data;
while (rx_counter==0);
data=rx_buffer[rx_rd_index];
if (++rx_rd_index == RX_BUFFER_SIZE) rx_rd_index=0;
#asm("cli")
--rx_counter;
#asm("sei")
return data;
}
#pragma used-
#endif

// USART Transmitter buffer
#define TX_BUFFER_SIZE 8
char tx_buffer[TX_BUFFER_SIZE];

#if TX_BUFFER_SIZE<256
unsigned char tx_wr_index,tx_rd_index,tx_counter;
#else
unsigned int tx_wr_index,tx_rd_index,tx_counter;
#endif

// USART Transmitter interrupt service routine
interrupt [USART_TXC] void usart_tx_isr(void)
{
if (tx_counter)
   {
   --tx_counter;
   DIR=1;
   #asm("nop")
   #asm("nop")
   #asm("nop")
   #asm("nop")
   UDR=tx_buffer[tx_rd_index];
   if (++tx_rd_index == TX_BUFFER_SIZE) tx_rd_index=0;
   }
else
   {
   DIR=0;
   #asm("nop")
   #asm("nop")
   #asm("nop")
   #asm("nop")
   }
}

#ifndef _DEBUG_TERMINAL_IO_
// Write a character to the USART Transmitter buffer
#define _ALTERNATE_PUTCHAR_
#pragma used+
void putchar(char c)
{
while (tx_counter == TX_BUFFER_SIZE);
#asm("cli")
if (tx_counter || ((UCSRA & DATA_REGISTER_EMPTY)==0))
   {
   tx_buffer[tx_wr_index]=c;
   if (++tx_wr_index == TX_BUFFER_SIZE) tx_wr_index=0;
   ++tx_counter;
   }
else
   {
   DIR=1;
   #asm("nop")
   #asm("nop")
   #asm("nop")
   #asm("nop")
   UDR=c;
   }
#asm("sei")
}

#pragma used-
#endif

// Standard Input/Output functions
#include <stdio.h>

void Serial_Test(void)
{
      char Temp[2][6];

      clearLCD();
      LCDprintf2(0,2,"Temp1= ");
      LCDprintf2(0,3,"Temp2= ");
      Temp[0][0]=getchar();
      Temp[0][1]=getchar();
      Temp[0][2]=getchar();
      Temp[0][3]=getchar();
      Temp[0][4]=getchar();
      Temp[0][5]=getchar();

      Temp[1][0]=getchar();
      Temp[1][1]=getchar();
      Temp[1][2]=getchar();
      Temp[1][3]=getchar();
      Temp[1][4]=getchar();
      Temp[1][5]=getchar();

      LCDprintf3(7,2,Temp[0]);
      LCDprintf3(7,3,Temp[1]);
}

void Send_to_CPU(unsigned char Commond,unsigned char Data)
{
      char str[4];
      itoa(Data,str);
      putchar('#');
      putchar(Commond);
      #asm("nop")
      putchar('*');
      #asm("nop")
      putchar(str[0]);      
      #asm("nop")
      putchar(str[1]);      
      #asm("nop")
      putchar(str[2]);      
      #asm("nop")
      putchar(str[3]);      
}