Colony

/**

 * Copyright (c) 2007 Colony Project

 * 

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 * 

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 **/

/**

 * @file serial.c

 * @brief Serial Input and Output

 *

 * Implementation of functions for serial input and output.

 *

 * @author Colony Project, CMU Robotics Club

 **/

#include <avr/io.h>

#include <stdio.h>

#include "serial.h"

FILE *usb_fd;  //For use with fprintf() and related stdio functions

FILE *xbee_fd;  //For use with fprintf() and related stdio functions

/**

 * Initializes communication over the USB serial port.

 * This must be called before any other usb function

 * may be used.

 **/

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 = 103;

    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

}

/**

 * Initializes communication over the XBee.

 * This must be called before any other xbee function

 * may be used.

 **/

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 = 103;

    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

}

/**

 * Sends a character over USB.

 *

 * @param c the character to send

 * @return 0 for success, nonzero for failure

 **/

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;

}

/**

 * Sends a character to the XBee.

 *

 * @param c the character to send

 * @return 0 for success, nonzero for failure

 **/

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;

}

/**

 * Sends a sequence of characters over USB.

 *

 * @param s the string to send

 * @return 0 for success, nonzero for failure

 **/

int usb_puts(char *s)

{

	char *t = s;

	while (*t != 0)

	{

		usb_putc(*t);

		t++;

	}

  return 0;

}

/**

 * Returns the first character in the buffer received from USB.

 * This function blocks execution until a character has been received.

 * xbee_init must be called before this function may be used.

 * 

 * @return the first character in the usb buffer

 *

 * @see usb_init, usb_getc_nb

 **/

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;

}

/**

 * Returns the first character in the buffer received from USB.

 * This function blocks execution until a character has been

 * received. xbee_init must be called before this function

 * may be used.

 * 

 * @return the first character in the xbee buffer

 * 

 * @see xbee_init, xbee_getc_nb

 **/

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;

}

/**

 * Non blocking version of usb_getc. If a character is present in the buffer,

 * it is returned, otherwise -1 is returned immediately. usb_init must be

 * called before this function can be used.

 *

 * @param c the received character. This will be set if a character has

 * been received.

 * 

 * @return -1 if no character is available, 0 otherwise

 * 

 * @see usb_init, usb_getc

 **/

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;

	}

}

/**

 * Non blocking version of xbee_getc. If a character is present in the buffer,

 * it is returned, otherwise -1 is returned immediately. xbee_init

 * must be called before this function can be used.

 *

 * @param c the received character. This will be set if a character has

 * been received.

 * 

 * @return -1 if no character is available, 0 otherwise

 *

 * @see xbee_init, xbee_getc

 **/

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

*/

/**

 * Prints an integer, converted to ASCII, to usb. usb_init must be called

 * before this function can be used.

 *

 * @param value the integer to print

 * 

 * @return 0 if successful, nonzero otherwise

 *

 * @see usb_init, 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;

}