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/*
* MIT License
*
* Copyright (c) 2021 Joey Castillo
*
* 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.
*/
#include <math.h>
#include "watch_utility.h"
const char * watch_utility_get_weekday(watch_date_time date_time) {
static const char weekdays[7][3] = {"SA", "SU", "MO", "TU", "WE", "TH", "FR"};
date_time.unit.year += 20;
if (date_time.unit.month <= 2) {
date_time.unit.month += 12;
date_time.unit.year--;
}
return weekdays[(date_time.unit.day + 13 * (date_time.unit.month + 1) / 5 + date_time.unit.year + date_time.unit.year / 4 + 525) % 7];
}
uint32_t watch_utility_convert_to_unix_time(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second, uint32_t utc_offset) {
uint16_t DAYS_SO_FAR[] = {
0, // Jan
31, // Feb
59, // March
90, // April
120, // May
151, // June
181, // July
212, // August
243, // September
273, // October
304, // November
334 // December
};
uint32_t year_adj = year + 4800;
uint32_t febs = year_adj - (month <= 2 ? 1 : 0); /* Februaries since base. */
uint32_t leap_days = 1 + (febs / 4) - (febs / 100) + (febs / 400);
uint32_t days = 365 * year_adj + leap_days + DAYS_SO_FAR[month - 1] + day - 1;
days -= 2472692; /* Adjust to Unix epoch. */
uint32_t timestamp = days * 86400;
timestamp += (hour + utc_offset) * 3600;
timestamp += minute * 60;
timestamp += second;
return timestamp;
}
uint32_t watch_utility_date_time_to_unix_time(watch_date_time date_time, uint32_t utc_offset) {
return watch_utility_convert_to_unix_time(date_time.unit.year + WATCH_RTC_REFERENCE_YEAR, date_time.unit.month, date_time.unit.day, date_time.unit.hour, date_time.unit.minute, date_time.unit.second, utc_offset);
}
float watch_utility_thermistor_temperature(uint16_t value, bool highside, float b_coefficient, float nominal_temperature, float nominal_resistance, float series_resistance) {
float reading = (float)value;
if (highside) {
reading = (1023.0 * series_resistance) / (reading / 64.0);
reading -= series_resistance;
} else {
reading = series_resistance / (65535.0 / value - 1.0);
}
reading = reading / nominal_resistance;
reading = log(reading);
reading /= b_coefficient;
reading += 1.0 / (nominal_temperature + 273.15);
reading = 1.0 / reading;
reading -= 273.15;
return reading;
}
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