view Discovery/Src/unit.c @ 224:ceecabfddb57 div-fixes-3

Bugfix, deco: fix 2 (small) problems with calculated ceiling This fixes 1 trivial, and 1 not really trivial bug in the calculation of the ceiling. When simulating a bounce dive to 80m, things become clear (tried this on a CCR dive, fixed setpoint 1.2bar, about 15 minutes of bottom time). Closely watch the behavior of the ceiling data. At some point during the ascent, the ceiling begins to decrease in 10cm steps. Then suddenly (while still ascending), the ceiling increases again with 1m, does not change for some time, and then suddenly steps 1.1m less deep. While not very relevant to real deco diving, it is simply wrong. The reason for this is subtle. The algorithm used to find the ceiling is a sort of linear search, stepping down a meter, overshoot the depth, and search back in 10cm steps. It seems some numerical instability. Fixing this, was a bit more computational intensive search by stepping up down in equal steps of 10cm. But, I'm pretty sure that things can be speeded up here, as a ceiling does not change fast, so it should be not that difficult to limit the search space, or use a binary search algorithm instead. The trivial second problem fixed, is that the ceiling ends at the surface and not at 1m depth. This small issue became visible after changing the step down size above. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
author Jan Mulder <jlmulder@xs4all.nl>
date Sun, 31 Mar 2019 19:35:51 +0200
parents 5f11787b4f42
children 1c95f811967c
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///////////////////////////////////////////////////////////////////////////////
/// -*- coding: UTF-8 -*-
///
/// \file   Discovery/Src/unit.c
/// \brief  input to meter/celsius or feet/farenheit
/// \author heinrichs weikamp gmbh
/// \date   24-Feb-2015
///
/// \details
///
/// $Id$
///////////////////////////////////////////////////////////////////////////////
/// \par Copyright (c) 2014-2018 Heinrichs Weikamp gmbh
///
///     This program is free software: you can redistribute it and/or modify
///     it under the terms of the GNU General Public License as published by
///     the Free Software Foundation, either version 3 of the License, or
///     (at your option) any later version.
///
///     This program is distributed in the hope that it will be useful,
///     but WITHOUT ANY WARRANTY; without even the implied warranty of
///     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
///     GNU General Public License for more details.
///
///     You should have received a copy of the GNU General Public License
///     along with this program.  If not, see <http://www.gnu.org/licenses/>.
//////////////////////////////////////////////////////////////////////////////

/* Includes ------------------------------------------------------------------*/
#include "unit.h"
#include "settings.h"

/* Exported variables --------------------------------------------------------*/

/* Private types -------------------------------------------------------------*/
uint8_t  test;

/* Private variables ---------------------------------------------------------*/

/* Private variables with external access via get_xxx() function -------------*/

/* Private function prototypes -----------------------------------------------*/

/* Announced function prototypes -----------------------------------------------*/

/* Exported functions --------------------------------------------------------*/

char unit_depth_char1_T105(void)
{
    if(settingsGetPointer()->nonMetricalSystem)
        return '\'';
    else
        return 'm';
}

char unit_depth_char2_T105(void)
{
    if(settingsGetPointer()->nonMetricalSystem)
        return ' ';
    else
        return '\004'; // 004 is nop
}

char unit_depth_char1(void)
{
    if(settingsGetPointer()->nonMetricalSystem)
        return 'f';
    else
        return 'm';
}

char unit_depth_char2(void)
{
    if(settingsGetPointer()->nonMetricalSystem)
        return 't';
    else
        return '\004'; // 004 is nop
}

float unit_depth_float(float input_meter)
{
    if(settingsGetPointer()->nonMetricalSystem == 0)
        return input_meter;
    else
    {
        return 3.2808f * input_meter;
    }
}

uint16_t unit_depth_integer(uint16_t input_meter)
{
    if(settingsGetPointer()->nonMetricalSystem == 0)
        return input_meter;
    else
    {
        return (input_meter * 10) / 3;
    }
}

float unit_temperature_float(float input_celsius)
{
    if(settingsGetPointer()->nonMetricalSystem == 0)
        return input_celsius;
    else
    {
        return input_celsius * (9.0f/5.0f) + 32;
    }
}

uint16_t unit_speed_integer(uint16_t input_meterPerMinute)
{
    if(settingsGetPointer()->nonMetricalSystem == 0)
        return input_meterPerMinute;
    else
    {
        return (input_meterPerMinute * 10) / 3;
    }
}

/* Quelle: https://de.wikipedia.org/wiki/Luftdruck */
/*
const float luftdruckStartMinus300[15] =
{
    1.0530f,
    1.0396f,
    1.0263f,
    1.01325f, // 0 m
    1.0003f,
    0.9876f,
    0.9750f,
    0.9625f,
    0.9503f,
    0.9381f,
    0.9262f,
    0.9144f,
    0.9027f,
    0.8912f, // 1000 m
    0.8358f
};
*/

const int luftdruckStartMinus300[15] =
{
    1053,
    1040,
    1026,
    1013, // 0 m
    1000,
     988,
     975,
     962,
     950,
     938,
     926,
     914,
     903,
     891, // 1000 m
     836
};


int unit_SeaLevelRelation_integer(int input_atmospheric_mbar)
{
    int i = 0;
    int distance1, distance2;
    for(i=0;i<15;i++)
    {
        if(input_atmospheric_mbar >= luftdruckStartMinus300[i])
            break;
    }

    if(i >= 14)
        return 1500;
    else if(i == 0)
        return -300;
    else
    {
        distance1 = input_atmospheric_mbar - luftdruckStartMinus300[i];
        distance2 = luftdruckStartMinus300[i-1] - input_atmospheric_mbar;
        if(distance2 < distance1)
            i -= 1;
        return (i*100) - 300;
    }
}