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/*
* Copyright © 2012 Keith Packard <keithp@keithp.com>
*
* 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 2 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, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <ao_ms5607.h>
void
ao_ms5607_convert(struct ao_ms5607_sample *sample, struct ao_ms5607_value *value)
{
int32_t dT;
int32_t TEMP;
int64_t OFF;
int64_t SENS;
dT = sample->temp - ((int32_t) ao_ms5607_prom.tref << 8);
TEMP = 2000 + (((int64_t) dT * ao_ms5607_prom.tempsens) >> 23);
#if HAS_MS5611
OFF = ((int64_t) ao_ms5607_prom.off << 16) + (((int64_t) ao_ms5607_prom.tco * dT) >> 7);
SENS = ((int64_t) ao_ms5607_prom.sens << 15) + (((int64_t) ao_ms5607_prom.tcs * dT) >> 8);
#else
OFF = ((int64_t) ao_ms5607_prom.off << 17) + (((int64_t) ao_ms5607_prom.tco * dT) >> 6);
SENS = ((int64_t) ao_ms5607_prom.sens << 16) + (((int64_t) ao_ms5607_prom.tcs * dT) >> 7);
#endif
if (TEMP < 2000) {
int32_t T2 = ((int64_t) dT * (int64_t) dT) >> 31;
int32_t TEMPM = TEMP - 2000;
int64_t OFF2 = (61 * (int64_t) TEMPM * (int64_t) TEMPM) >> 4;
int64_t SENS2 = 2 * (int64_t) TEMPM * (int64_t) TEMPM;
if (TEMP < -1500) {
int32_t TEMPP = TEMP + 1500;
/* You'd think this would need a 64-bit int, but
* that would imply a temperature below -327.67°C...
*/
int32_t TEMPP2 = TEMPP * TEMPP;
OFF2 = OFF2 + (int64_t) 15 * TEMPP2;
SENS2 = SENS2 + (int64_t) 8 * TEMPP2;
}
TEMP -= T2;
OFF -= OFF2;
SENS -= SENS2;
}
value->pres = ((((int64_t) sample->pres * SENS) >> 21) - OFF) >> 15;
value->temp = TEMP;
}
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