Luth Haroon / SD_modified

SD card interface

mbed-export/rtc_time.h@0:22612ae617a0, 2012-10-08 (annotated)

Committer:
lharoon
Date:
Mon Oct 08 11:14:07 2012 +0000
Revision:
0:22612ae617a0
1st edition

Who changed what in which revision?

UserRevisionLine numberNew contents of line
lharoon 0:22612ae617a0 1 /* Title: time
lharoon 0:22612ae617a0 2 * Implementation of the C time.h functions
lharoon 0:22612ae617a0 3 *
lharoon 0:22612ae617a0 4 * Provides mechanisms to set and read the current time, based
lharoon 0:22612ae617a0 5 * on the microcontroller Real-Time Clock (RTC), plus some
lharoon 0:22612ae617a0 6 * standard C manipulation and formating functions.
lharoon 0:22612ae617a0 7 *
lharoon 0:22612ae617a0 8 * Example:
lharoon 0:22612ae617a0 9 * > #include "mbed.h"
lharoon 0:22612ae617a0 10 * >
lharoon 0:22612ae617a0 11 * > int main() {
lharoon 0:22612ae617a0 12 * > set_time(1256729737); // Set RTC time to Wed, 28 Oct 2009 11:35:37
lharoon 0:22612ae617a0 13 * >
lharoon 0:22612ae617a0 14 * > while(1) {
lharoon 0:22612ae617a0 15 * > time_t seconds = time(NULL);
lharoon 0:22612ae617a0 16 * >
lharoon 0:22612ae617a0 17 * > printf("Time as seconds since January 1, 1970 = %d\n", seconds);
lharoon 0:22612ae617a0 18 * >
lharoon 0:22612ae617a0 19 * > printf("Time as a basic string = %s", ctime(&seconds));
lharoon 0:22612ae617a0 20 * >
lharoon 0:22612ae617a0 21 * > char buffer[32];
lharoon 0:22612ae617a0 22 * > strftime(buffer, 32, "%I:%M %p\n", localtime(&seconds));
lharoon 0:22612ae617a0 23 * > printf("Time as a custom formatted string = %s", buffer);
lharoon 0:22612ae617a0 24 * >
lharoon 0:22612ae617a0 25 * > wait(1);
lharoon 0:22612ae617a0 26 * > }
lharoon 0:22612ae617a0 27 * > }
lharoon 0:22612ae617a0 28 */
lharoon 0:22612ae617a0 29
lharoon 0:22612ae617a0 30 /* mbed Microcontroller Library - rtc_time
lharoon 0:22612ae617a0 31 * Copyright (c) 2009 ARM Limited. All rights reserved.
lharoon 0:22612ae617a0 32 */
lharoon 0:22612ae617a0 33
lharoon 0:22612ae617a0 34 #include <time.h>
lharoon 0:22612ae617a0 35
lharoon 0:22612ae617a0 36 #ifdef __cplusplus
lharoon 0:22612ae617a0 37 extern "C" {
lharoon 0:22612ae617a0 38 #endif
lharoon 0:22612ae617a0 39
lharoon 0:22612ae617a0 40 #if 0 // for documentation only
lharoon 0:22612ae617a0 41 /* Function: time
lharoon 0:22612ae617a0 42 * Get the current time
lharoon 0:22612ae617a0 43 *
lharoon 0:22612ae617a0 44 * Returns the current timestamp as the number of seconds since January 1, 1970
lharoon 0:22612ae617a0 45 * (the UNIX timestamp). The value is based on the current value of the
lharoon 0:22612ae617a0 46 * microcontroller Real-Time Clock (RTC), which can be set using <set_time>.
lharoon 0:22612ae617a0 47 *
lharoon 0:22612ae617a0 48 * Example:
lharoon 0:22612ae617a0 49 * > #include "mbed.h"
lharoon 0:22612ae617a0 50 * >
lharoon 0:22612ae617a0 51 * > int main() {
lharoon 0:22612ae617a0 52 * > time_t seconds = time(NULL);
lharoon 0:22612ae617a0 53 * > printf("It is %d seconds since January 1, 1970\n", seconds);
lharoon 0:22612ae617a0 54 * > }
lharoon 0:22612ae617a0 55 *
lharoon 0:22612ae617a0 56 * Variables:
lharoon 0:22612ae617a0 57 * t - Pointer to a time_t to be set, or NULL if not used
lharoon 0:22612ae617a0 58 * returns - Number of seconds since January 1, 1970 (the UNIX timestamp)
lharoon 0:22612ae617a0 59 */
lharoon 0:22612ae617a0 60 time_t time(time_t *t);
lharoon 0:22612ae617a0 61 #endif
lharoon 0:22612ae617a0 62
lharoon 0:22612ae617a0 63 /* Function: set_time
lharoon 0:22612ae617a0 64 * Set the current time
lharoon 0:22612ae617a0 65 *
lharoon 0:22612ae617a0 66 * Initialises and sets the time of the microcontroller Real-Time Clock (RTC)
lharoon 0:22612ae617a0 67 * to the time represented by the number of seconds since January 1, 1970
lharoon 0:22612ae617a0 68 * (the UNIX timestamp).
lharoon 0:22612ae617a0 69 *
lharoon 0:22612ae617a0 70 * Example:
lharoon 0:22612ae617a0 71 * > #include "mbed.h"
lharoon 0:22612ae617a0 72 * >
lharoon 0:22612ae617a0 73 * > int main() {
lharoon 0:22612ae617a0 74 * > set_time(1256729737); // Set time to Wed, 28 Oct 2009 11:35:37
lharoon 0:22612ae617a0 75 * > }
lharoon 0:22612ae617a0 76 *
lharoon 0:22612ae617a0 77 * Variables:
lharoon 0:22612ae617a0 78 * t - Number of seconds since January 1, 1970 (the UNIX timestamp)
lharoon 0:22612ae617a0 79 */
lharoon 0:22612ae617a0 80 void set_time(time_t t);
lharoon 0:22612ae617a0 81
lharoon 0:22612ae617a0 82 #if 0 // for documentation only
lharoon 0:22612ae617a0 83 /* Function: mktime
lharoon 0:22612ae617a0 84 * Converts a tm structure in to a timestamp
lharoon 0:22612ae617a0 85 *
lharoon 0:22612ae617a0 86 * Converts the tm structure in to a timestamp in seconds since January 1, 1970
lharoon 0:22612ae617a0 87 * (the UNIX timestamp). The values of tm_wday and tm_yday of the tm structure
lharoon 0:22612ae617a0 88 * are also updated to their appropriate values.
lharoon 0:22612ae617a0 89 *
lharoon 0:22612ae617a0 90 * Example:
lharoon 0:22612ae617a0 91 * > #include "mbed.h"
lharoon 0:22612ae617a0 92 * >
lharoon 0:22612ae617a0 93 * > int main() {
lharoon 0:22612ae617a0 94 * > // setup time structure for Wed, 28 Oct 2009 11:35:37
lharoon 0:22612ae617a0 95 * > struct tm t;
lharoon 0:22612ae617a0 96 * > t.tm_sec = 37; // 0-59
lharoon 0:22612ae617a0 97 * > t.tm_min = 35; // 0-59
lharoon 0:22612ae617a0 98 * > t.tm_hour = 11; // 0-23
lharoon 0:22612ae617a0 99 * > t.tm_mday = 28; // 1-31
lharoon 0:22612ae617a0 100 * > t.tm_mon = 9; // 0-11
lharoon 0:22612ae617a0 101 * > t.tm_year = 109; // year since 1900
lharoon 0:22612ae617a0 102 * >
lharoon 0:22612ae617a0 103 * > // convert to timestamp and display (1256729737)
lharoon 0:22612ae617a0 104 * > time_t seconds = mktime(&t);
lharoon 0:22612ae617a0 105 * > printf("Time as seconds since January 1, 1970 = %d\n", seconds);
lharoon 0:22612ae617a0 106 * > }
lharoon 0:22612ae617a0 107 *
lharoon 0:22612ae617a0 108 * Variables:
lharoon 0:22612ae617a0 109 * t - The tm structure to convert
lharoon 0:22612ae617a0 110 * returns - The converted timestamp
lharoon 0:22612ae617a0 111 */
lharoon 0:22612ae617a0 112 time_t mktime(struct tm *t);
lharoon 0:22612ae617a0 113 #endif
lharoon 0:22612ae617a0 114
lharoon 0:22612ae617a0 115 #if 0 // for documentation only
lharoon 0:22612ae617a0 116 /* Function: localtime
lharoon 0:22612ae617a0 117 * Converts a timestamp in to a tm structure
lharoon 0:22612ae617a0 118 *
lharoon 0:22612ae617a0 119 * Converts the timestamp pointed to by t to a (statically allocated)
lharoon 0:22612ae617a0 120 * tm structure.
lharoon 0:22612ae617a0 121 *
lharoon 0:22612ae617a0 122 * Example:
lharoon 0:22612ae617a0 123 * > #include "mbed.h"
lharoon 0:22612ae617a0 124 * >
lharoon 0:22612ae617a0 125 * > int main() {
lharoon 0:22612ae617a0 126 * > time_t seconds = 1256729737;
lharoon 0:22612ae617a0 127 * > struct tm *t = localtime(&seconds);
lharoon 0:22612ae617a0 128 * > }
lharoon 0:22612ae617a0 129 *
lharoon 0:22612ae617a0 130 * Variables:
lharoon 0:22612ae617a0 131 * t - Pointer to the timestamp
lharoon 0:22612ae617a0 132 * returns - Pointer to the (statically allocated) tm structure
lharoon 0:22612ae617a0 133 */
lharoon 0:22612ae617a0 134 struct tm *localtime(const time_t *t);
lharoon 0:22612ae617a0 135 #endif
lharoon 0:22612ae617a0 136
lharoon 0:22612ae617a0 137 #if 0 // for documentation only
lharoon 0:22612ae617a0 138 /* Function: ctime
lharoon 0:22612ae617a0 139 * Converts a timestamp to a human-readable string
lharoon 0:22612ae617a0 140 *
lharoon 0:22612ae617a0 141 * Converts a time_t timestamp in seconds since January 1, 1970 (the UNIX
lharoon 0:22612ae617a0 142 * timestamp) to a human readable string format. The result is of the
lharoon 0:22612ae617a0 143 * format: "Wed Oct 28 11:35:37 2009\n"
lharoon 0:22612ae617a0 144 *
lharoon 0:22612ae617a0 145 * Example:
lharoon 0:22612ae617a0 146 * > #include "mbed.h"
lharoon 0:22612ae617a0 147 * >
lharoon 0:22612ae617a0 148 * > int main() {
lharoon 0:22612ae617a0 149 * > time_t seconds = time(NULL);
lharoon 0:22612ae617a0 150 * > printf("Time as a string = %s", ctime(&seconds));
lharoon 0:22612ae617a0 151 * > }
lharoon 0:22612ae617a0 152 *
lharoon 0:22612ae617a0 153 * Variables:
lharoon 0:22612ae617a0 154 * t - The timestamp to convert
lharoon 0:22612ae617a0 155 * returns - Pointer to a (statically allocated) string containing the
lharoon 0:22612ae617a0 156 * human readable representation, including a '\n' character
lharoon 0:22612ae617a0 157 */
lharoon 0:22612ae617a0 158 char *ctime(const time_t *t);
lharoon 0:22612ae617a0 159 #endif
lharoon 0:22612ae617a0 160
lharoon 0:22612ae617a0 161 #if 0 // for documentation only
lharoon 0:22612ae617a0 162 /* Function: strftime
lharoon 0:22612ae617a0 163 * Converts a tm structure to a custom format human-readable string
lharoon 0:22612ae617a0 164 *
lharoon 0:22612ae617a0 165 * Creates a formated string from a tm structure, based on a string format
lharoon 0:22612ae617a0 166 * specifier provided.
lharoon 0:22612ae617a0 167 *
lharoon 0:22612ae617a0 168 * Format Specifiers:
lharoon 0:22612ae617a0 169 * %S - Second (00-59)
lharoon 0:22612ae617a0 170 * %M - Minute (00-59)
lharoon 0:22612ae617a0 171 * %H - Hour (00-23)
lharoon 0:22612ae617a0 172 * %d - Day (01-31)
lharoon 0:22612ae617a0 173 * %m - Month (01-12)
lharoon 0:22612ae617a0 174 * %Y/%y - Year (2009/09)
lharoon 0:22612ae617a0 175 *
lharoon 0:22612ae617a0 176 * %A/%a - Weekday Name (Monday/Mon)
lharoon 0:22612ae617a0 177 * %B/%b - Month Name (January/Jan)
lharoon 0:22612ae617a0 178 * %I - 12 Hour Format (01-12)
lharoon 0:22612ae617a0 179 * %p - "AM" or "PM"
lharoon 0:22612ae617a0 180 * %X - Time (14:55:02)
lharoon 0:22612ae617a0 181 * %x - Date (08/23/01)
lharoon 0:22612ae617a0 182 *
lharoon 0:22612ae617a0 183 * Example:
lharoon 0:22612ae617a0 184 * > #include "mbed.h"
lharoon 0:22612ae617a0 185 * >
lharoon 0:22612ae617a0 186 * > int main() {
lharoon 0:22612ae617a0 187 * > time_t seconds = time(NULL);
lharoon 0:22612ae617a0 188 * >
lharoon 0:22612ae617a0 189 * > char buffer[32];
lharoon 0:22612ae617a0 190 * > strftime(buffer, 32, "%I:%M %p\n", localtime(&seconds));
lharoon 0:22612ae617a0 191 * > printf("Time as a formatted string = %s", buffer);
lharoon 0:22612ae617a0 192 * > }
lharoon 0:22612ae617a0 193 *
lharoon 0:22612ae617a0 194 * Variables:
lharoon 0:22612ae617a0 195 * buffer - String buffer to store the result
lharoon 0:22612ae617a0 196 * max - Maximum number of characters to store in the buffer
lharoon 0:22612ae617a0 197 * format - Format specifier string
lharoon 0:22612ae617a0 198 * t - Pointer to the tm structure to convert
lharoon 0:22612ae617a0 199 * returns - Number of characters copied
lharoon 0:22612ae617a0 200 */
lharoon 0:22612ae617a0 201 size_t strftime(char *buffer, size_t max, const char *format, const struct tm *t);
lharoon 0:22612ae617a0 202 #endif
lharoon 0:22612ae617a0 203
lharoon 0:22612ae617a0 204 #ifdef __cplusplus
lharoon 0:22612ae617a0 205 }
lharoon 0:22612ae617a0 206 #endif