AVR Simple UART - buffered/interrupt driven serial// v1.0
// 4/06 stevech@san.rr.com
Tested with mega8 at 10MHz.
Should be compiler-independent. Developed with Atman IDE for GCC.

HERE IS THE .H FILE

#define UBBRL_VALUE 31 // 10MHz CPU, 19.2Kbaud serial. See AVRcalc.exe

/* Buffersizes must be a power of 2 in size, for speed */
#define TBUFSIZE 64
#define RBUFSIZE 64

// functions in UART.c

void UART_init(void); // initialize

void UART_putc(unsigned char c); // put ASCII or non-ASCII byte, blocks if buffer full
unsigned char UART_getc(void); // get ASCII or non-ASCII byte,
// blocks if none available. See UART_rbuflen()

int UART_gets(char *p, int max); // Get string that ends with a \r but subject to max chars
void UART_puts(char *p); // print string from RAM
void UART_puts_P(char *p); // print string from FLASH MEMORY

unsigned char UART_tbuflen(void); // get number of as yet untransmitted bytes
unsigned char UART_rbuflen(void); // get number of bytes in the receive buffer or zero

// buffered I/O if fdevopen() is to be used.
// Matches AVR library as of 4/06
// put the next two lines in main()
// fdevopen( UART_fputchar, UART_fgetchar ); // establish buffered I/O callbacks
// sei(); // Global interrupt enable
int UART_fgetc(FILE *);
int UART_fputc(char, FILE *);