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 bom.c

 * @brief Implementation for using the BOM

 *

 * Contains functions for using the Bearing and Orientation Module (BOM)

 *

 * @author Colony Project, CMU Robotics Club

 **/

#include <dragonfly_lib.h>

#include "bom.h"

#include "dio.h"

#include "analog.h"

//constants

const int lookup[16] = {7,6,5,0xe,1,4,3,2,0xf,0,0xd,8,0xc,0xb,9,0xa};

// internal function prototypes

void output_high(int which);

void output_low(int which);

/*

 Bk R Y (Analog)

---------

 Green

 Blue

 White

---------

 Blue

 White

*/

/*

the analog pin definitions from dio.h DO NOT work here,

so we must use PF0 from avrgcc (as opposed to _PIN_F0).

BUT the dio pin definitions from dio.h must be used (no PE...).

also, _PIN_E2 is initialized to high for some reason,

which turns the BOM on when the robot is turned on.

WORK-AROUND: call digital_output(_PIN_E2,0) at some point.

*/

#define MONKI PF0         //analog (yellow)

//------------------------//

#define MONKL _PIN_E2     //green

#define MONK1 _PIN_E3     //blue

#define MONK0 _PIN_E4     //white

//------------------------//

#define MONK3 _PIN_E6     //blue

#define MONK2 _PIN_E7     //white

#define BOM_VALUE_THRESHOLD 200

/**

 * @defgroup bom BOM (Bearing and Orientation Module)

 * @brief Functions for dealing with the BOM.

 *

 * The Bearing and Orientation Module / Barrel of Monkeys / BOM

 * is a custom sensor designed and built by the Colony Project.

 * It consists of a ring of 16 IR emitters and 16 IR detectors.

 * The BOM is most often use to determine the direction of other

 * robots. This module contains functions for controlling the BOM.

 *

 * Include bom.h to access these functions.

 *

 * @{

 **/

/**

 * Returns the direction of the maximum BOM reading,

 * as an integer in the range 0-15. 0 indicates to the

 * robot's right, while the rest of the sensors are

 * numbered counterclockwise. This is useful for determining

 * the direction of a robot flashing its BOM, of only one

 * robot is currently doing so. analog_init must be called

 * before this function can be used.

 *

 * @return the direction of the maximum BOM reading

 *

 * @see analog_init

 **/

int get_max_bom(void) {

  int max_bom_temp = 0;

  int a, i, j, h;

  h = 255;

  for (j = 0; j < 16; j++) {

    i = lookup[j];

    if (i&8) {

      output_high(MONK3);

    } else {

      output_low(MONK3);

    }

    if (i&4) {

      output_high(MONK2);

    } else {

      output_low(MONK2);

    }

    if (i&2) {

      output_high(MONK1);

    } else {

      output_low(MONK1);

    }

    if (i&1) {

      output_high(MONK0);

    } else {

      output_low(MONK0);

    }

    a = analog8(MONKI);

    if (a < h) {

      h = a;

      max_bom_temp = j;

    }

  }

  //threshold on the bom analog value.

  //defined in bom.h

  // if the analog value read is above the threshold, we cannot see a robot

  // (remember, low means higher intensity).

  if (h < BOM_VALUE_THRESHOLD) {

    return max_bom_temp;

  } else {

    return -1;

  }

}

/**

 * Flashes the BOM. analog_init must be called before this

 * function can be used.

 *

 * @see bom_off, analog_init

 **/

void bom_on(void)

{

  output_high(MONKL);

}

/**

 * Stops flashing the BOM. analog_init must be called

 * before this function can be used.

 *

 * @see bom_on, analog_init

 **/

void bom_off(void)

{

  output_low(MONKL);

}

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

void output_high(int which)

{

  digital_output(which, 1);

}

void output_low(int which)

{

  digital_output(which, 0);

}