OpenRTX/openrtx/src/calibUtils.c

52 wiersze
2.3 KiB
C

/***************************************************************************
* Copyright (C) 2020 by Federico Amedeo Izzo IU2NUO, *
* Niccolò Izzo IU2KIN, *
* Silvano Seva IU2KWO *
* *
* 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/> *
***************************************************************************/
#include <calibUtils.h>
uint8_t interpCalParameter(const freq_t freq, const freq_t *calPoints,
const uint8_t *param, const uint8_t elems)
{
if(freq <= calPoints[0]) return param[0];
if(freq >= calPoints[elems - 1]) return param[elems - 1];
/* Find calibration point nearest to target frequency */
uint8_t pos = 0;
for(; pos < elems; pos++)
{
if(calPoints[pos] >= freq) break;
}
uint8_t interpValue = 0;
freq_t delta = calPoints[pos] - calPoints[pos - 1];
if(param[pos - 1] < param[pos])
{
interpValue = param[pos - 1] + ((freq - calPoints[pos - 1]) *
(param[pos] - param[pos - 1]))/delta;
}
else
{
interpValue = param[pos - 1] - ((freq - calPoints[pos - 1]) *
(param[pos - 1] - param[pos]))/delta;
}
return interpValue;
}