500 Year Calendar for DT Elapsed Timer
Hi Guys,
Here’s my 500 year calendar that can be used with Darrel Taylor’s Elapsed Timer routines (when used as a clock).
There’s a video demonstration coming up shortly
This can save you a RTC/Calendar Chip such as Maxim/Dallas 1307/1302 when you are already using the clock routine.
The DS1307 is only accurate to the year 2100, where I have checked accuracy against iOS in the range 1800-2300.
Usage:
Set your variables calday, calmonth, calyear with the input numbers and call setcal subroutine.
If the date made sense, and the year was within range 1800-2300 the flag calbadentry will be zero.
If the year was out of range or you used a number that was too high for day or months (i.e. entered 29th of Feb when it was not a leap year),
the number for day or month will be set to 1, and the value for calbadentry will be 1
for your program to throw an error.
If the year is out of range it gets adjusted back to the upper or lower limit.
The variable caldow will contain the day of the week where zero is Sunday through to 6 for Saturday.
From there you can just check the value of DayChanged with he provided code waiting for the day to change,
and the program routine will increment the date and weekday each day.
The lookup table epochyears contains 12 years that begin on a Monday to make the calendar faster.
The calendar routine only has to iterate from the closest year before the current year the user input.
During testing the weekday and leap year routines were tested against the stock iPhone calendar App.
Implementation:
In the Elasped.bas file, add the DayChanged bit like so:
You will also need to make a small change to the sequence that increments the time variablesCode:TicksChanged var bit SecondsChanged var bit DayChanged var bit
to wrap around after 24 hours (if you haven’t done so for a clock already),
and set the DayChanged status every 24 hours.
Code:Ticks = Ticks + 1 if Ticks = 100 then Ticks = 0 Seconds = Seconds + 1 SecondsChanged = 1 if Seconds = 60 then Seconds = 0 Minutes = Minutes + 1 endif if Minutes = 60 then Minutes = 0 Hours = Hours + 1 endif if Hours = 24 then <———— Hours = 0 DayChanged = 1 ‘ <————— endif endif
In your own main program file, declare some calendar variables:
reset some variables in a place that is only run once at startup,Code:caldim var byte [12] ' calendar days in months calday var word ' calendar day calmonth var word ' calendar month calyear var word ' calendar year caldow var byte ' calendar day of the week calleap var bit ' current year leap status bit calbadentry var bit ' bad calendar input flag cacnt var word ' counter for calendar cwork var word ' work buffer for calendar xwork var word ' work buffer for calendar calleapx var bit ' leap year buffer for calendar
and set a default date (be sure the date is in range 1800-2300.
Now somewhere in your main program that cycles, check this code regularly:Code:calyear = 2015 ' set default date to 01/01/2015 calday = 0 ' day is incremented to 1 at startup DayChanged = 1 ' because this day changed flag is set calmonth = 1 ' month defaults to January
Code:‘ program initialisation ‘ tris something = something ‘ some flag = 0 calyear = 2015 ' set default date to 01/01/2015 calday = 0 ' day is incremented to 1 at startup DayChanged = 1 ' because this day changed flag is set calmonth = 1 ' month defaults to January main: ‘ your main program.. ' increment date if day changed over ' if DayChanged = 1 then calday = calday + 1 if calday > caldim[calmonth-1] then calday = 1 calmonth = calmonth + 1 endif if calmonth > 12 then calmonth = 1 calyear = calyear + 1 endif ' DayChanged = 0 gosub setcal endif ' DayChanged ' ‘ goto main ‘
This is the calendar that is called as a subroutine called “setcal”:
Code:‘ ‘ ‘ 500 year calendar for pic (tested with 16F877A) by Brek Martin (Art) 2015. ‘ ‘ This is free software. Please credit the author if it’s reused or distributed. ' ' ******************* set calendar date and find day of week ******************* ' setcal: ' find leap year status caldim[0] = 31 ' set default days in month table caldim[1] = 28 ' days in February is changed to 29 by the program caldim[2] = 31 ' caldim[3] = 30 ' caldim[4] = 31 ' caldim[5] = 30 ' caldim[6] = 31 ' caldim[7] = 31 ' caldim[8] = 30 ' caldim[9] = 31 ' caldim[10] = 30 ' caldim[11] = 31 ' ' calleap = 0 ' clear leap year status if calyear // 4 = 0 then ' calleap = 1 ' set leap year status if calyear // 100 = 0 then ' calleap = 0 ' clear leap year status if calyear // 400 = 0 then ' calleap = 1 ' set leap year status endif ' endif ' endif ' ' if calleap = 1 then ' caldim[1] = 29 ' endif ' ' calbadentry = 0 ' reset calendar bad entry status if calmonth = 0 then ' check for invalid date input calbadentry = 1 ' calmonth = 1 ' endif ' if calmonth > 12 then ' calbadentry = 1 ' calmonth = 1 ' endif ' if calday = 0 then ' calbadentry = 1 ' calday = 1 ' endif ' if calday > caldim[calmonth-1] then calbadentry = 1 ' calday = 1 ' endif ' if calyear < 1800 then ' implement lower year range restriction calbadentry = 1 ' prevent far away dates slowing program down calyear = 1800 ' endif ' if calyear > 2300 then ' implement higher year range restriction calbadentry = 1 ' in case of errors far into the future calyear = 2300 ' endif ' the hardware probably won't last that long ' ' day of week ' xwork = 2310 ' find best epoch year to iterate from cacnt = 12 ' while xwork >= calyear ' gosub epochyears ' cacnt = cacnt - 1 ' wend ' ' ' cwork = 0 ' working variable for days ' for cacnt = xwork to calyear - 1' iterate years from epoch year calleapx = 0 ' clear leap year status if cacnt // 4 = 0 then ' calleapx = 1 ' set leap year status if cacnt // 100 = 0 then ' calleapx = 0 ' clear leap year status if cacnt // 400 = 0 then ' calleapx = 1 ' set leap year status endif ' endif ' endif ' ' if calleapx = 0 then ' add days over the years from epoch cwork = (cwork + 365)//7 ' else ' cwork = (cwork + 366)//7 ' endif ' ' next cacnt ' ' if calleap = 1 then ' fix day of month table for current year caldim[1] = 29 ' else ' caldim[1] = 28 ' endif ' ' cacnt = calmonth-1 ' add days for elapsed months of current year while cacnt > 0 ' xwork = caldim[cacnt-1] ' cwork = (cwork + xwork)//7 ' cacnt = cacnt - 1 ' wend ' ' cacnt = calday-1 ' add days elapsed of current month xwork = 0 ' while cacnt > 0 ' xwork = xwork + 1 ' cacnt = cacnt - 1 ' wend ' cwork = (cwork + xwork)//7 ' ' ' caldow = cwork + 1 ' shift range for display so 0=Sunday, 6=Saturday. if caldow = 7 then caldow = 0 ' return ' ' epochyears: lookup2 cacnt,[1798,1849,1900,1951,1990,2035,2052,2091,2125,2153,2198,2227,2244],xwork return '
Cheers, Art.
Originally Posted by amgen
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