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 "bom.h"

#include "dio.h"

#include "serial.h"

#include "analog.h"

//On the original BOM1.0, the emmitter angular order does not match the analog mux order

//so you need to iterate through the mux index in the following order if you want to get

//the detector readings in order:

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

// internal function prototypes

static void bom_select(char 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 150 //200

#define NUM_BOM_LEDS 16

/*

  *The following pin definitions are for the BOM v1.5

  */

#define BOM_MODE        _PIN_E2        //dio0

#define BOM_STROBE        _PIN_E3        //dio1

#define BOM_DATA        _PIN_A0 //servo0

#define BOM_CLOCK        _PIN_A1        //servo1

#define BOM_S0                _PIN_E5        //dio3

#define BOM_S1                _PIN_E4        //dio2

#define BOM_S2                _PIN_E7        //dio4

#define BOM_S3                _PIN_E6        //dio5

#define BOM_OUT                PF0                //analog(yellow)

/**

 * @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.

 *

 * @{

 **/

static unsigned int bom_val[NUM_BOM_LEDS];

static volatile char bom_type = BOM10;

static int select_pins[4];

static int analog_pin;

/**

 * Initializes the BOM.

 * Call bom_init before reading bom values or turning bom leds.

 *

 * @bugs INCOMPLETE - No utilization of BOM1.5 RSSI capability. Probably leave this out

 * until Cornell and Pras return

 * 

 * @see bom_refresh, bom_leds_on, bom_leds_off

 **/

void bom_init(char type) {

    bom_type = type;

    switch(bom_type) {

    case BOM10:

                select_pins[0] = MONK0; 

                select_pins[1] = MONK1;

                select_pins[2] = MONK2;

                select_pins[3] = MONK3;

                analog_pin = MONKI;

        break;

    case BOM15:

        //Sets BOM1.5 to normal [BOM] mode

        digital_output(BOM_MODE, 0);

                select_pins[0] = BOM_S0; 

                select_pins[1] = BOM_S1;

                select_pins[2] = BOM_S2;

                select_pins[3] = BOM_S3;

                bom_set_leds(BOM_ALL);

                analog_pin = BOM_OUT;

        break;

    case RBOM:

        break;

    //default:

    }

}

/**

 * Iterates through each bit in the bit_field. For each set bit, sets the corresponding bom select bits

 *    and updates the corresponding bom value with an analog_get8 reading.  analog_init and bom_init

 *    must be called for this to work. Must call this before reading BOM values!

 *

 *

 * @param bit_field specifies which elements in bom_val[] should be updated. Use BOM_ALL to refresh all values.

 *    Ex. if 0x0003 is passed, bom_val[0] and bom_val[1] will be updated.

 *

 * @see bom_get

 **/

void bom_refresh(int bit_field) {

    int i;

        int loop_was_running = 0;

        //Check analog loop status

    if(analog_loop_status() == ADC_LOOP_RUNNING) {

                loop_was_running = 1;

                analog_stop_loop();

        }

        //Read BOM values

    for(i = 0; i < NUM_BOM_LEDS; i++) {

        if(bit_field & 0x1) {

            bom_select(i);

            bom_val[i] = analog_get8(analog_pin);

        }

        bit_field = bit_field >> 1;

    }

        //Restore analog loop status

        if(loop_was_running)

                analog_start_loop();

}

/**

 * Gets the bom reading from bom_val[which].  Call bom_refresh beforehand to read new bom values.

 *

 * @pre must call bom refresh first

 *

 * @param which which bom value to return

 *

 * @return the bom value

 *

 * see bom_refresh

 **/

int bom_get(int which) {

    return bom_val[which];

}

/** 

 * Compares all the values in bom_val[] and returns the index to the lowest (max) value element.

 *

 * @pre must call bom refresh

 * @return index to the lowest (max) bom value element.  -1 if no value is lower than

 *    BOM_VALUE_THRESHOLD

 **/

int bom_get_max(void) {

    int i, lowest_val, lowest_i;

    lowest_i = -1;

    lowest_val = 255;

    for(i = 0; i < NUM_BOM_LEDS; i++) {

        if(bom_val[i] < lowest_val) {

            lowest_val = bom_val[i];

            lowest_i = i;

        }

    }

    if(lowest_val < BOM_VALUE_THRESHOLD)

        return lowest_i;

    else

        return -1;

}

/** 

 * Computes the weighted average of all the bom readings to estimate the position (and distance) of another robot.

 *

 * @pre must call bom refresh

 * @param dist  pointer to int in which to return the estimated distance to the other robot

 * @return estimated position of the max bom value element as a fixed point value analogous to 10 times the

 *        index of the max bom value.  -1 if no value is lower than BOM_VALUE_THRESHOLD.

 **/

int bom_get_max10(int *dist) {

    int i, max;

    long long mean = 0, sum = 0;

    max = bom_get_max();

    if (max < 0)

    {

        if (dist)

        {

            *dist = -1;

        }

        return -1;

    }

    /* Record values into an array */

    for (i = 0; i < NUM_BOM_LEDS; i++) {

        int idx = ((i + (NUM_BOM_LEDS/2 - max) + NUM_BOM_LEDS) % NUM_BOM_LEDS) - (NUM_BOM_LEDS/2 - max);

        int val = 255 - bom_val[i];

        mean += idx * val;

        sum += val;

    }

    mean = (mean * 10) / sum;

    mean = (mean + NUM_BOM_LEDS*10) % (NUM_BOM_LEDS*10);

    if (dist)

    {

        *dist = 50 - sum/48;

    }

    return mean;

}

/**

 * Iterates through each bit in the bit_field. If the bit is set, the corresponding emitter will

 *    be enabled to turn on when bom_on() is called.

 *    bom_init must be called for this to work. Does nothing if a BOM1.0 is installed

 *

 * @param bit_field specifies which leds should be turned on when bom_on is called.  Use BOM_ALL to turn on all bom leds.

 *    Ex. if 0x0005 is passed, leds 0 and 2 will be turned on.

 **/

void bom_set_leds(int bit_field) {

    int i;

        unsigned int mask = 1<<(NUM_BOM_LEDS-1);

        switch(bom_type) {

    case BOM10:

        //TODO: put an assert here to alert the user that this should not be called

        break;

    case BOM15:

            for(i=NUM_BOM_LEDS; i>0; i--)

            {

                    //set the current bit, sending MSB first

                    digital_output(BOM_DATA, bit_field&mask);

                    //then pulse the clock

                    digital_output(BOM_CLOCK, 1);

                    digital_output(BOM_CLOCK, 0);

                        mask = mask>>1;

            }

        break;

    case RBOM:

        //add rbom code here

        break;

    }

}

/**

 * (DEPRECATED) 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) {

    bom_refresh(BOM_ALL);

    return bom_get_max();

}

/**

 * Flashes the BOM.  If using a BOM1.5, only the emitters that have been enabled using

 * bom_set_leds will turn on.

 * 

 * @see bom_off, bom_set_leds

 **/

void bom_on(void)

{

  switch(bom_type) {

  case BOM10:

        digital_output(MONKL, 1);

        break;

  case BOM15:

        digital_output(BOM_STROBE, 1);

        break;

  case RBOM:

        break;

  }

}

/**

 * Turns off all bom leds.

 * 

 * @see bom_on

 **/

void bom_off(void)

{

  switch(bom_type) {

  case BOM10:

        digital_output(MONKL, 0);

        break;

  case BOM15:

        digital_output(BOM_STROBE, 0);

        break;

  case RBOM:

        break;

  }

}

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

//select a detector to read

static void bom_select(char which) {

        if(bom_type == BOM10)

          which = lookup[(int)which];

    if (which&8)

      digital_output(select_pins[3], 1);

    else

      digital_output(select_pins[3], 0);

    if (which&4)

      digital_output(select_pins[2], 1);

    else

      digital_output(select_pins[2], 0);

    if (which&2)

      digital_output(select_pins[1], 1);

    else

      digital_output(select_pins[1], 0);

    if (which&1)

      digital_output(select_pins[0], 1);

    else

      digital_output(select_pins[0], 0);

}