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 buzzer

 * @brief Functions for using the buzzer

 *

 * Contains functions for using the buzzer.

 *

 * @author Colony Project, CMU Robotics Club

 *

 * much taken from FWR's firefly library (author: Tom Lauwers)

 **/

#include <avr/io.h>

#include <buzzer.h>

#include <time.h>

/**

 * @defgroup buzzer Buzzer

 * @brief Functions for controlling the buzzer.

 * Functions for controlling the buzzer. Include

 * buzzer.h to access these functions.

 * @{

 **/

/**

 * Initializes the buzzer. Must be called before any other buzzer

 * function may be used.

 **/

void buzzer_init( void )

{

        //NOTE: This is mostly handled by buzzer_Set_val for now

        // Set pin B7 to output - B7 is buzzer pin

        //DDRB |= _BV(DDB7);

        //Fast PWM Mode, Clear OCR0 on compare match and set at bottom, clock/64

        //TCCR2 = _BV(COM20) | _BV(WGM21)  | _BV(CS22);

}

/**

 * Sets the value of the buzzer's pitch.

 * Higher values are lower frequencies.

 *

 * @param buzz_value the value to set the buzzer's frequency too,

 * in the range 0-255

 *

 * @see buzzer_init, buzzer_set_freq, buzzer_off

 **/

void buzzer_set_val(unsigned int buzz_value)

{

        TCCR2 = _BV(COM20) | _BV(WGM21)  | _BV(CS22);

        DDRB |= _BV(DDB7);

        OCR2 = buzz_value;

}

/**

 * Sets the buzzer frequency. Usage of constants such as C4

 * is highly recommended as input to this function.

 * buzzer_init must be called before this function may

 * be used.

 *

 * @param buzz_freq the frequency to set the buzzer to

 *

 * @see buzzer_init, buzzer_set_val, buzzer_off

 **/

void buzzer_set_freq(unsigned int buzz_freq)

{

  int buzz_value;

  buzz_value = 62500/buzz_freq - 1;

  if(buzz_value > 255){

    buzz_value = 255;

  }else if(buzz_value < 0){

    buzz_value = 0;

  }

  buzzer_set_val(buzz_value);

}

/**

 * Plays the specified frequency for the specified

 * amount of time. This function blocks execution

 * until the time is completed. buzzer_init must be

 * called before this function can be used.

 *

 * @param ms the time in milliseconds to play the frequency

 * @param buzz_freq the frequency to play

 *

 * @see buzzer_init, buzzer_set_freq

 **/

void buzzer_chirp(unsigned int ms, unsigned int buzz_freq)

{

  buzzer_set_freq(buzz_freq);

  delay_ms(ms);

  buzzer_off();

}

/**

 * Turns off the buzzer by disabling the timer0 clock.

 *

 * @see buzzer_init

 **/

void buzzer_off()

{

  // Disable clock, to halt counter

  TCCR2 &= 0xF8;//0b11111000;

  // Set buzzer pin low in case it's high

  PORTB &= 0xBF;//0b10111111;

}

/** @} **/ // end buzzer group