Added datetime to ASCII function.

src/bacnet/datetime.c

@@ -1431,9 +1431,9 @@ int datetime_time_to_ascii(BACNET_TIME *btime, char *str, size_t str_size)
 }
 
 /**
- * @brief Parse an ascii string for the date+time 2021/12/31 23:59:59.99
+ * @brief Parse an ascii string for the date+time 2021/12/31-23:59:59.99
  * @param bdate - #BACNET_DATE_TIME structure
- * @param argv - C string with date+time formatted 2021/12/31 23:59:59.99
+ * @param argv - C string with date+time formatted 2021/12/31-23:59:59.99
  * @return true if parsed successfully
  */
 bool datetime_init_ascii(BACNET_DATE_TIME *bdatetime, const char *ascii)
@@ -1457,3 +1457,31 @@ bool datetime_init_ascii(BACNET_DATE_TIME *bdatetime, const char *ascii)
 
     return status;
 }
+
+/**
+ * @brief Print the date and time as an ascii string 2021/12/31-23:59:59.99
+ * @param btime - pointer to a BACnetTime
+ * @param str - pointer to the string, or NULL for length only
+ * @param str_size - size of the string, or 0 for length only
+ * @return number of characters printed
+ */
+int datetime_to_ascii(BACNET_DATE_TIME *bdatetime, char *str, size_t str_size)
+{
+    int str_len = 0;
+
+    if (!bdatetime) {
+        return 0;
+    }
+    /* 2021/12/31-23:59:59.99 */
+    str_len = snprintf(str, str_size,
+        "%04u/%02u/%02u-%02u:%02u:%02u.%02u",
+        (unsigned)bdatetime->date.year,
+        (unsigned)bdatetime->date.month,
+        (unsigned)bdatetime->date.day,
+        (unsigned)bdatetime->time.hour,
+        (unsigned)bdatetime->time.min,
+        (unsigned)bdatetime->time.sec,
+        (unsigned)bdatetime->time.hundredths);
+
+    return str_len;
+}

src/bacnet/datetime.h

@@ -257,6 +257,8 @@ BACNET_STACK_EXPORT
 int datetime_time_to_ascii(BACNET_TIME *btime, char *str, size_t str_size);
 BACNET_STACK_EXPORT
 bool datetime_init_ascii(BACNET_DATE_TIME *bdatetime, const char *ascii);
+BACNET_STACK_EXPORT
+int datetime_to_ascii(BACNET_DATE_TIME *bdatetime, char *str, size_t str_size);
 
 BACNET_STACK_EXPORT
 int bacapp_encode_datetime(uint8_t *apdu, BACNET_DATE_TIME *value);

test/bacnet/datetime/src/main.c

@@ -590,6 +590,15 @@ static void testDatetimeCodec(void)
     }
     diff = datetime_compare(&datetimeOut, &datetimeIn);
     zassert_equal(diff, 0, NULL);
+    /* test datetime stringify */
+    status = datetime_init_ascii(&datetimeIn, "1904/2/1-5:06:07.8");
+    zassert_true(status, NULL);
+    str_len = datetime_to_ascii(&datetimeIn, str, sizeof(str));
+    zassert_true(str_len > 0, NULL);
+    status = datetime_init_ascii(&datetimeOut, str);
+    zassert_true(status, NULL);
+    diff = datetime_compare(&datetimeOut, &datetimeIn);
+    zassert_equal(diff, 0, NULL);
 }
 
 static void testDatetimeConvertUTCSpecific(BACNET_DATE_TIME *utc_time,