Colony

/*

        serial.c - Functions for using the RS232 serial port

        authors: Robotics Club, Colony Project, pkv

        much code taken from FWR's library, author: Tom Lauwers

*/

#include <avr/io.h>

#include <stdio.h>

#include "serial.h"

/* usb_init() - sets up AVR for communication over the usb serial port */

void usb_init() {

  //Set baud rate

  // - 115200 (both wired and wireless) is UBRR=8, U2X=1

  // - 9600 is U2X =1, UBRR = 107.

        #if (USB_BAUD == 115200)

    UBRR0H = 0x00;

    UBRR0L = 8;

    UCSR0A |= _BV(U2X0);

  #elif (USB_BAUD == 9600)

    UBRR0H = 0x00;

    UBRR0L = 107;

    UCSR0A |= _BV(U2X0);

  #else //Baud rate is defined in the header file, we should not get here

    return;

  #endif

  /*Enable receiver and transmitter */

        UCSR0B |= (1<<RXEN0)|(1<<TXEN0);

        /* Set frame format: 8data, 1stop bit, asynchronous normal mode */

        UCSR0C |= (1<<UCSZ00) | (1<<UCSZ01);

  // if we have enabled the stdio stuff, then we init it here

  #ifdef USE_STDIO

    /* Open the stdio stream corresponding to this port */

    usb_fd = fdevopen(usb_putc, usb_getc);

  #endif

}

/* xbee_init() - sets up AVR for communication over the xbee serial port */

void xbee_init() {

  //Set baud rate

  // - 115200 (both wired and wireless) is UBRR=8, U2X=1

  // - 9600 is U2X =1, UBRR = 107.

        #if (XBEE_BAUD == 115200)

    UBRR1H = 0x00;

    UBRR1L = 8;

    UCSR1A |= _BV(U2X1);

  #elif (XBEE_BAUD == 9600)

    UBRR1H = 0x00;

    UBRR1L = 107;

    UCSR1A |= _BV(U2X1);

  #else //Baud rate is defined in the header file, we should not get here

    return;

  #endif

        //Enable receiver and transmitter

        UCSR1B |= (1<<RXEN1)|(1<<TXEN1);

        // Set frame format: 8data, 1stop bit, asynchronous normal mode

        UCSR1C |= (1<<UCSZ10) | (1<<UCSZ11);

  // if we have enabled the stdio stuff, then we init it here

  #ifdef USE_STDIO

    /* Open the stdio stream corresponding to this port */

    xbee_fd = fdevopen(xbee_putc, xbee_getc);

  #endif

}

/* usb_putc(c) - waits until the usb serial tx buffer is clear, then 

  puts the character c into the buffer */

int usb_putc(char c) 

{

  // Wait until buffer is clear for sending

  loop_until_bit_is_set(UCSR0A, UDRE0);

  // Load buffer with your character

  UDR0 = c;

  return 0;

}

/* xbee_putc(c) - waits until the xbee serial tx buffer is clear, then 

  puts the character c into the buffer */

int xbee_putc(char c) 

{

  // Wait until buffer is clear for sending

  loop_until_bit_is_set(UCSR1A, UDRE1);

  // Load buffer with your character

  UDR1 = c;

  return 0;

}

/* usb_puts(c) - writes each character from the string to the usb */

int usb_puts(char *s)

{

        char *t = s;

        while (*t != 0)

        {

                usb_putc(*t);

                t++;

        }

  return 0;

}

/* usb_getc() - waits until the usb serial rx buffer is not empty, then 

  returns the first character in the buffer */

int usb_getc(void)

{

  // Wait for the receive buffer to be filled

  loop_until_bit_is_set(UCSR0A, RXC0);

        // Read the receive buffer

        return UDR0;

}

/* xbee_getc() - waits until the xbee serial rx buffer is not empty, then 

  returns the first character in the buffer */

int xbee_getc(void)

{

        // Wait for the receive buffer to be filled

    loop_until_bit_is_set(UCSR1A, RXC1);

        // Read the receive buffer

        return UDR1;

}

/* usb_getc_nb(*c) - checks if the usb serial rx buffer is empty or not:

  -If it is empty, c is unchanged and -1 is returned.  

  -If is not empty, the first character in the buffer is loaded into c,

    and 0 is returned */

int usb_getc_nb(char *c)

{

        // check if the receive buffer is filled

  if (UCSR0A & _BV(RXC0)) {

    // Read the receive buffer

    (*c) = UDR0;

    return 0;

  }

  else {

    // Return empty

    return -1;

        }

}

/* xbee_getc_nb(*c) - checks if the xbee serial rx buffer is empty or not:

  -If it is empty, c is unchanged and -1 is returned.  

  -If is not empty, the first character in the buffer is loaded into c,

    and 0 is returned */

int xbee_getc_nb(char *c)

{

        // check if the receive buffer is filled

  if (UCSR1A & _BV(RXC1)) {

    // Read the receive buffer

    (*c) = UDR1;

    return 0;

  }

  else {

    // Return empty

    return -1;

        }

}

/*

prints an int to serial

code adapted from Chris Efstathiou's code (hendrix@otenet.gr)

uses usb_putc

*/

int usb_puti(int value ) {

        unsigned char usb_data[6]={'0','0','0','0','0','0' }, position=sizeof(usb_data), radix=10; 

        /* convert int to ascii  */ 

        if(value<0) { usb_putc('-'); value=-value; }    

        do { position--; *(usb_data+position)=(value%radix)+'0'; value/=radix;  } while(value); 

        /* start displaying the number */

        for(;position<=(sizeof(usb_data)-1);position++)

          {

            usb_putc(usb_data[position]);

          }

        return 0;

}