pic16_usart.c

#ifdef DEBUG

#include "usart.h"
#include "hardware.h"
#include "interrupt.h"
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <stdarg.h>

#define TIMEOUT (30000)

static volatile bool          _data_available;
static volatile unsigned char _received_char;

static volatile int foo = 0;
void usart_putc(unsigned char out)
{
    while(!TXSTAbits.TRMT);
    TXREG = out;    
}

void usart_puts(const unsigned char *buf)
{
    while(*buf != '\0') {
        usart_putc(*buf++);
    }
}

void usart_putln(const unsigned char *buf)
{
    usart_puts(buf);
    usart_putc('\n');
}

#define PRINTF_MAX_LEN (64)
void usart_printf(const unsigned char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    char outbuf[PRINTF_MAX_LEN+1];
    char *outbuf_head = outbuf;
    char *fmt_head = fmt;

    uint16_t outlen = 0;
    #define APPEND(c) do { \
        if(outlen < PRINTF_MAX_LEN-1) { \
            *outbuf_head++ = (c); \
            ++outlen; \
        } else continue; \
    } while(0)

    char *temp;
    while(*fmt_head != '\0' && outlen < PRINTF_MAX_LEN) {
        if(*fmt_head == '%') {
            char fmt_char = *(fmt_head+1);
            fmt_head += 2;
            switch(fmt_char) {
                case 'd':
                    temp = itoa(outbuf_head, va_arg(ap, int), 10);
                    outlen      += strlen(temp);
                    outbuf_head += strlen(temp);
                    break;
                default:
                    APPEND('%');
                    APPEND(fmt_char);
            }
        } else
            APPEND(*fmt_head++);
    }
    #undef APPEND
    outbuf[outlen] = '\0';
    usart_puts(outbuf);

    va_end(ap);
}

unsigned char usart_read_char(void)
{
    if(_data_available) {
        _data_available = false;
        return _received_char;
    } else
        return 0;
}

uint16_t usart_read(unsigned char *out_buf, uint16_t max_len)
{
    unsigned char c;
    uint16_t len = 0;
    for(; len < max_len; ++len) {
        c = 0;
        while(c == 0) {
            c = usart_read_char();
        }
        *out_buf++ = c;
        if(c == '\0')
            break;
    }
    return len;
}

void usart_interrupt_handler(void)
{
    _data_available = true;
    _received_char = RCREG;
   // usart_putc(_received_char);
}

void usart_init(void)
{
    // SPBRGL = 207 => 9600  baud
    // SPBRGL = 34  => 57600 baud
    SPBRGL  = 34;
    SPBRGH  = 0;
    BAUDCON = 0;           // 8 bit baud rate generator used
    TXSTA = 0;
    TXSTAbits.TXEN = true; // Enable transmission
    TXSTAbits.BRGH = true; // High baud rate
    RCSTAbits.SPEN = true; // Enable serial port
    RCSTAbits.CREN = true; // Enable continuous receival

   // PIE1bits.RCIE = true;  // Enable  USART rcv interrupt
   // PIE1bits.TXIE = false; // Disable USART snd interrupt

//    KEEP_FUN(usart_interrupt_handler);
//    int_register_handler(int_rx, &usart_interrupt_handler);
}

#endif