main.cpp

00001 #include "mbed.h"
00002 #include "time.h"
00003 #include "TextLCD.h"
00004 #include "EthernetNetIf.h"
00005 #include "NTPClient.h"
00006 
00007 #define TIMEZONE (9 * 60 * 60)
00008 
00009 TextLCD lcd(p21, p22, p23, p24, p25, p26);
00010 
00011 EthernetNetIf eth;
00012 NTPClient ntp;
00013 
00014 unsigned long convert_gregorian_to_julian(int year, int month, int day)
00015 {
00016     if (month < 3) {
00017         month += 9;
00018         year--;
00019     } else {
00020         month -= 3;
00021     }
00022     year += 4800;
00023     int c = year / 100;
00024     return c * 146097 / 4 + (year - c * 100) * 1461 / 4 + (153 * month + 2) / 5 + day - 32045;
00025 }
00026 
00027 void convert_julian_to_gregorian(unsigned long j, int *year, int *month, int *day)
00028 {
00029     int y, m, d;
00030     y = (j * 4 + 128179) / 146097;
00031     d = (j * 4 - y * 146097 + 128179) / 4 * 4 + 3;
00032     j = d / 1461;
00033     d = (d - j * 1461) / 4 * 5 + 2;
00034     m = d / 153;
00035     d = (d - m * 153) / 5 + 1;
00036     y = (y - 48) * 100 + j;
00037     if (m < 10) {
00038         m += 3;
00039     } else {
00040         m -= 9;
00041         y++;
00042     }
00043     *year = y;
00044     *month = m;
00045     *day = d;
00046 }
00047 
00048 void display(int year, int month, int day, int hour, int minute, int second)
00049 {
00050     lcd.cls();
00051     lcd.printf("%04u-%02u-%02u\n", year, month, day);
00052     lcd.printf("%02u:%02u:%02u\n", hour, minute, second);
00053 }
00054 
00055 int main()
00056 {
00057     eth.setup();
00058 
00059     Host server(IpAddr(), 123, "ntp.jst.mfeed.ad.jp");
00060 
00061     bool adjust = true;
00062 
00063     double last = 0;
00064 
00065     while (1) {
00066         if (adjust) {
00067             ntp.setTime(server);
00068             adjust = false;
00069         } else {
00070             wait(0.1);
00071         }
00072 
00073         time_t t = time(0);
00074         double s = t + 2440588.0 * 24 * 60 * 60; // chronological julian second
00075 
00076         if (s > last) {
00077             last = s;
00078 
00079             s += TIMEZONE;
00080 
00081             unsigned long cjd = (unsigned long)(s / (24 * 60 * 60)); // chronological julian day
00082             int year, month, day, hour, minute, second;
00083             convert_julian_to_gregorian(cjd, &year, &month, &day);
00084             second = (int)fmod(s, 24 * 60 * 60);
00085             hour = second / (60 * 60);
00086             minute = second / 60 % 60;
00087             second %= 60;
00088 
00089             display(year, month, day, hour, minute, second);
00090 
00091             if (minute == 59 && second == 30) {
00092                 adjust = true;
00093             }
00094         }
00095     }
00096 
00097     return 0;
00098 }
00099