use RTC to get date and time

application.c

@@ -22,6 +22,7 @@
 #include <stdint.h> // standard integer types
 #include <stdlib.h> // standard utilities
 #include <string.h> // string utilities
+#include <time.h> // date/time utilities
 
 /* STM32 (including CM3) libraries */
 #include <libopencmsis/core_cm3.h> // Cortex M3 utilities
@@ -49,6 +50,8 @@
 volatile bool rtc_internal_tick_flag = false; /**< flag set when internal RTC ticked */
 /** @} */
 
+time_t time_rtc = 0; /**< time (seconds since Unix Epoch) */
+struct tm* time_tm; /**< time in tm format (time zones are not handled for non-POSIX environments) */
 
 size_t putc(char c)
 {
@@ -117,6 +120,42 @@ static void process_command(char* str)
 		} else {
 			goto error;
 		}
+	} else if (0==strcmp(word,"time")) {
+		word = strtok(NULL,delimiter);
+		if (!word) {
+			time_rtc = rtc_get_counter_val(); // get time from internal RTC
+			time_tm = localtime(&time_rtc); // convert time
+			printf("time: %02d:%02d:%02d\n", time_tm->tm_hour, time_tm->tm_min, time_tm->tm_sec);
+		} else if (strlen(word)!=8 || word[0]<'0' || word[0]>'2' || word[1]<'0' || word[1]>'9' || word[3]<'0' || word[3]>'5' || word[4]<'0' || word[4]>'9' || word[6]<'0' || word[6]>'5' || word[7]<'0' || word[7]>'9') { // time format is incorrect
+				goto error;
+		} else {
+			time_rtc = rtc_get_counter_val(); // get time from internal RTC
+			time_tm = localtime(&time_rtc); // convert time
+			time_tm->tm_hour = (word[0]-'0')*10+(word[1]-'0')*1; // set hours
+			time_tm->tm_min = (word[3]-'0')*10+(word[4]-'0')*1; // set minutes
+			time_tm->tm_sec = (word[6]-'0')*10+(word[7]-'0')*1; // set seconds
+			time_rtc = mktime(time_tm); // get back seconds
+			rtc_set_counter_val(time_rtc); // save time to internal RTC
+			printf("time set\n");
+		}
+	} else if (0==strcmp(word,"date")) {
+		word = strtok(NULL,delimiter);
+		if (!word) {
+			time_rtc = rtc_get_counter_val(); // get time from internal RTC
+			time_tm = localtime(&time_rtc); // convert time
+			printf("date: %d-%02d-%02d\n", 1900+time_tm->tm_year, time_tm->tm_mon, time_tm->tm_mday);
+		} else if (strlen(word)!=10 || word[0]!='2' || word[1]!='0' || word[2]<'0' || word[2]>'9' || word[3]<'0' || word[3]>'9' || word[5]<'0' || word[5]>'1' || word[6]<'0' || word[6]>'9' || word[8]<'0' || word[8]>'3' || word[9]<'0' || word[9]>'9') {
+				goto error;
+		} else {
+			time_rtc = rtc_get_counter_val(); // get time from internal RTC
+			time_tm = localtime(&time_rtc); // convert time
+			time_tm->tm_year = ((word[0]-'0')*1000+(word[1]-'0')*100+(word[2]-'0')*10+(word[3]-'0')*1)-1900; // set year
+			time_tm->tm_mon = (word[5]-'0')*10+(word[6]-'0')*1; // set month
+			time_tm->tm_mday = (word[8]-'0')*10+(word[9]-'0')*1; // set day
+			time_rtc = mktime(time_tm); // get back seconds
+			rtc_set_counter_val(time_rtc); // save time to internal RTC
+			printf("date set\n");
+		}
 	} else {
 		goto error;
 	}
@@ -173,8 +212,9 @@ void main(void)
 	nvic_enable_irq(NVIC_RTC_IRQ); // allow the RTC to interrupt
 	printf("OK\n");
 
-	uint32_t ticks_time = rtc_get_counter_val(); // get time from internal RTC (since first start/power up)
-	printf("uptime: %lu.%02lu:%02lu:%02lu\n", ticks_time/(60*60*24), (ticks_time/(60*60))%24, (ticks_time%(60*60))/60, (ticks_time%60)); // display uptime
+	time_rtc= rtc_get_counter_val(); // get time from internal RTC
+	time_tm = localtime(&time_rtc); // convert time
+	printf("date: %d-%02d-%02d %02d:%02d:%02d\n", 1900+time_tm->tm_year, time_tm->tm_mon, time_tm->tm_mday, time_tm->tm_hour, time_tm->tm_min, time_tm->tm_sec);
 
 	// main loop
 	printf("command input: ready\n");
@@ -224,13 +264,14 @@ void main(void)
 		}
 		while (rtc_internal_tick_flag) { // the internal RTC ticked
 			rtc_internal_tick_flag = false; // reset flag
+			action = true; // action has been performed
 #if !defined(BLUE_PILL) // on the blue pill the LED is close to the 32.768 kHz oscillator and heavily influences it
 			led_toggle(); // toggle LED (good to indicate if main function is stuck)
 #endif
-			ticks_time = rtc_get_counter_val(); // copy time from internal RTC for processing
-			action = true; // action has been performed
-			if ((ticks_time%(60))==0) { // one minute passed
-				printf("uptime: %lu.%02lu:%02lu:%02lu\n", ticks_time/(60*60*24), (ticks_time/(60*60))%24, (ticks_time%(60*60))/60, (ticks_time%60)); // display uptime
+			time_rtc = rtc_get_counter_val(); // get time from internal RTC (seconds since Unix Epoch)
+			time_tm = localtime(&time_rtc); // get time in tm format from Epoch (time zones are not handled for non-POSIX environments)
+			if (0==time_tm->tm_sec) { // new minute
+				printf("time: %02d:%02d:%02d\n", time_tm->tm_hour, time_tm->tm_min, time_tm->tm_sec);
 			}
 		}
 		if (action) { // go to sleep if nothing had to be done, else recheck for activity