diff options
Diffstat (limited to 'watch-library/shared/watch/watch_utility.c')
| -rw-r--r-- | watch-library/shared/watch/watch_utility.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/watch-library/shared/watch/watch_utility.c b/watch-library/shared/watch/watch_utility.c new file mode 100644 index 00000000..835076d9 --- /dev/null +++ b/watch-library/shared/watch/watch_utility.c @@ -0,0 +1,172 @@ +/* + * 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 * 3600; + timestamp += minute * 60; + timestamp += second; + timestamp -= utc_offset; + + 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); +} + +#define LEAPOCH (946684800LL + 86400*(31+29)) + +#define DAYS_PER_400Y (365*400 + 97) +#define DAYS_PER_100Y (365*100 + 24) +#define DAYS_PER_4Y (365*4 + 1) + +watch_date_time watch_utility_date_time_from_unix_time(uint32_t timestamp, uint32_t utc_offset) { + watch_date_time retval; + retval.reg = 0; + int32_t days, secs; + int32_t remdays, remsecs, remyears; + int32_t qc_cycles, c_cycles, q_cycles; + int32_t years, months; + int32_t wday, yday, leap; + static const int8_t days_in_month[] = {31,30,31,30,31,31,30,31,30,31,31,29}; + timestamp += utc_offset; + + secs = timestamp - LEAPOCH; + days = secs / 86400; + remsecs = secs % 86400; + if (remsecs < 0) { + remsecs += 86400; + days--; + } + + wday = (3+days)%7; + if (wday < 0) wday += 7; + + qc_cycles = (int)(days / DAYS_PER_400Y); + remdays = days % DAYS_PER_400Y; + if (remdays < 0) { + remdays += DAYS_PER_400Y; + qc_cycles--; + } + + c_cycles = remdays / DAYS_PER_100Y; + if (c_cycles == 4) c_cycles--; + remdays -= c_cycles * DAYS_PER_100Y; + + q_cycles = remdays / DAYS_PER_4Y; + if (q_cycles == 25) q_cycles--; + remdays -= q_cycles * DAYS_PER_4Y; + + remyears = remdays / 365; + if (remyears == 4) remyears--; + remdays -= remyears * 365; + + leap = !remyears && (q_cycles || !c_cycles); + yday = remdays + 31 + 28 + leap; + if (yday >= 365+leap) yday -= 365+leap; + + years = remyears + 4*q_cycles + 100*c_cycles + 400*qc_cycles; + + for (months=0; days_in_month[months] <= remdays; months++) + remdays -= days_in_month[months]; + + years += 2000; + + months += 2; + if (months >= 12) { + months -=12; + years++; + } + + if (years < 2020 || years > 2083) return retval; + retval.unit.year = years - WATCH_RTC_REFERENCE_YEAR; + retval.unit.month = months + 1; + retval.unit.day = remdays + 1; + + retval.unit.hour = remsecs / 3600; + retval.unit.minute = remsecs / 60 % 60; + retval.unit.second = remsecs % 60; + + return retval; +} + +watch_date_time watch_utility_date_time_convert_zone(watch_date_time date_time, uint32_t origin_utc_offset, uint32_t destination_utc_offset) { + uint32_t timestamp = watch_utility_date_time_to_unix_time(date_time, origin_utc_offset); + return watch_utility_date_time_from_unix_time(timestamp, destination_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; +} |