Joseph Ellsworth / compile_time_to_system_time

Function to convert compiler macro __DATE__ and __TIME__ to a system time that can be used to initialize the CPU RTC. I use this to do a 1 time initialization of a RTC chip.

Dependents:   xj-Init-clock-to-compile-time-if-not-already-initialized-ds1302

Parse compiler DATE and TIME into a time_t structure

I use this to initialize the system time RTC using set_time() to a value parsed from the DATE and TIME strings. I find it easier to recompile and reload the firmware than it is to manually type the time string.

Sample Use

https://developer.mbed.org/users/joeata2wh/code/xj-Init-clock-to-compile-time-if-not-alr extends the use of this library to set the DS1302 clock chip to the compile time only the first time the utility runs. After that it detects a sentinel already stored in the clock chip and used the previously saved time.

Referenced:

compile_time_to_system_time.h@2:c746c1b8671f, 2016-05-07 (annotated)

Committer:
joeata2wh
Date:
Sat May 07 02:06:11 2016 +0000
Revision:
2:c746c1b8671f
Parent:
1:3e55cf9d76e6 
month was 1 digit to high

Who changed what in which revision?

UserRevisionLine numberNew contents of line
joeata2wh 0:5f3730f44e19 1 /* Function to convert compile time reported as
joeata2wh 0:5f3730f44e19 2 MBED compiler macro into a System time we can
joeata2wh 0:5f3730f44e19 3 use to set time and date in our chip. This can
joeata2wh 0:5f3730f44e19 4 be a helpful way to initialize clock chips for
joeata2wh 0:5f3730f44e19 5 low volume tests
joeata2wh 1:3e55cf9d76e6 6
joeata2wh 1:3e55cf9d76e6 7 By Joseph Ellsworth CTO of A2WH
joeata2wh 1:3e55cf9d76e6 8 Take a look at A2WH.com Producing Water from Air using Solar Energy
joeata2wh 1:3e55cf9d76e6 9 March-2016 License: https://developer.mbed.org/handbook/MIT-Licence
joeata2wh 1:3e55cf9d76e6 10 Please contact us http://a2wh.com for help with custom design projects.
joeata2wh 1:3e55cf9d76e6 11
joeata2wh 0:5f3730f44e19 12
joeata2wh 0:5f3730f44e19 13 call with the command
joeata2wh 0:5f3730f44e19 14 printf("compile time=%s date=%s\r\n",__TIME__,__DATE__);
joeata2wh 0:5f3730f44e19 15 time_t build_time = cvt_date(__DATE__,__TIME__);
joeata2wh 0:5f3730f44e19 16 printf("compile time reformate=%s r\n", ctime(&build_time));
joeata2wh 0:5f3730f44e19 17
joeata2wh 1:3e55cf9d76e6 18
joeata2wh 1:3e55cf9d76e6 19 TODO: Enhance to read time from clock chip and if unreasable
joeata2wh 1:3e55cf9d76e6 20 then re-initialize the time. I have found a small number
joeata2wh 1:3e55cf9d76e6 21 of instances when the clock lost the time due to battery
joeata2wh 1:3e55cf9d76e6 22 run down but the init byte was still present. This enhancement
joeata2wh 1:3e55cf9d76e6 23 should accomodate that.
joeata2wh 0:5f3730f44e19 24
joeata2wh 0:5f3730f44e19 25 */
joeata2wh 0:5f3730f44e19 26
joeata2wh 0:5f3730f44e19 27 #ifndef compile_time_to_system_time_H
joeata2wh 0:5f3730f44e19 28 #define compile_time_to_system_time_H
joeata2wh 0:5f3730f44e19 29
joeata2wh 0:5f3730f44e19 30
joeata2wh 0:5f3730f44e19 31 // call with the command
joeata2wh 0:5f3730f44e19 32 //time_t build_time = cvt_date(__DATE__,__TIME__);
joeata2wh 0:5f3730f44e19 33
joeata2wh 0:5f3730f44e19 34 // Convert compile time to system time
joeata2wh 0:5f3730f44e19 35 time_t cvt_date(char const *date, char const *time)
joeata2wh 0:5f3730f44e19 36 {
joeata2wh 0:5f3730f44e19 37 char s_month[5];
joeata2wh 0:5f3730f44e19 38 int year;
joeata2wh 0:5f3730f44e19 39 struct tm t;
joeata2wh 0:5f3730f44e19 40 static const char month_names[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
joeata2wh 0:5f3730f44e19 41 sscanf(date, "%s %d %d", s_month, &t.tm_mday, &year);
joeata2wh 0:5f3730f44e19 42 sscanf(time, "%2d %*c %2d %*c %2d", &t.tm_hour, &t.tm_min, &t.tm_sec);
joeata2wh 0:5f3730f44e19 43 // Find where is s_month in month_names. Deduce month value.
joeata2wh 2:c746c1b8671f 44 t.tm_mon = (strstr(month_names, s_month) - month_names) / 3;
joeata2wh 0:5f3730f44e19 45 t.tm_year = year - 1900;
joeata2wh 0:5f3730f44e19 46 return mktime(&t);
joeata2wh 0:5f3730f44e19 47 }
joeata2wh 0:5f3730f44e19 48
joeata2wh 0:5f3730f44e19 49
joeata2wh 0:5f3730f44e19 50 #endif