1 // Code by JeeLabs http://news.jeelabs.org/code/
2 // Released to the public domain! Enjoy!
5 #include <avr/pgmspace.h>
8 #define DS1307_ADDRESS 0x68
9 #define SECONDS_PER_DAY 86400L
11 #define SECONDS_FROM_1970_TO_2000 946684800
14 #include <Arduino.h> // capital A so it is error prone on case-sensitive filesystems
19 int i = 0; //The new wire library needs to take an int when you are sending for the zero register
20 ////////////////////////////////////////////////////////////////////////////////
21 // utility code, some of this could be exposed in the DateTime API if needed
23 const uint8_t daysInMonth [] PROGMEM = { 31,28,31,30,31,30,31,31,30,31,30,31 }; //has to be const or compiler compaints
25 // number of days since 2000/01/01, valid for 2001..2099
26 static uint16_t date2days(uint16_t y, uint8_t m, uint8_t d) {
30 for (uint8_t i = 1; i < m; ++i)
31 days += pgm_read_byte(daysInMonth + i - 1);
32 if (m > 2 && y % 4 == 0)
34 return days + 365 * y + (y + 3) / 4 - 1;
37 static long time2long(uint16_t days, uint8_t h, uint8_t m, uint8_t s) {
38 return ((days * 24L + h) * 60 + m) * 60 + s;
41 ////////////////////////////////////////////////////////////////////////////////
42 // DateTime implementation - ignores time zones and DST changes
43 // NOTE: also ignores leap seconds, see http://en.wikipedia.org/wiki/Leap_second
45 DateTime::DateTime (uint32_t t) {
46 t -= SECONDS_FROM_1970_TO_2000; // bring to 2000 timestamp from 1970
53 uint16_t days = t / 24;
55 for (yOff = 0; ; ++yOff) {
57 if (days < 365 + leap)
62 uint8_t daysPerMonth = pgm_read_byte(daysInMonth + m - 1);
65 if (days < daysPerMonth)
72 DateTime::DateTime (uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t min, uint8_t sec) {
83 static uint8_t conv2d(const char* p) {
85 if ('0' <= *p && *p <= '9')
87 return 10 * v + *++p - '0';
90 // A convenient constructor for using "the compiler's time":
91 // DateTime now (__DATE__, __TIME__);
92 // NOTE: using PSTR would further reduce the RAM footprint
93 DateTime::DateTime (const char* date, const char* time) {
94 // sample input: date = "Dec 26 2009", time = "12:34:56"
95 yOff = conv2d(date + 9);
96 // Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
98 case 'J': m = date[1] == 'a' ? 1 : m = date[2] == 'n' ? 6 : 7; break;
99 case 'F': m = 2; break;
100 case 'A': m = date[2] == 'r' ? 4 : 8; break;
101 case 'M': m = date[2] == 'r' ? 3 : 5; break;
102 case 'S': m = 9; break;
103 case 'O': m = 10; break;
104 case 'N': m = 11; break;
105 case 'D': m = 12; break;
107 d = conv2d(date + 4);
109 mm = conv2d(time + 3);
110 ss = conv2d(time + 6);
113 uint8_t DateTime::dayOfWeek() const {
114 uint16_t day = date2days(yOff, m, d);
115 return (day + 6) % 7; // Jan 1, 2000 is a Saturday, i.e. returns 6
118 uint32_t DateTime::unixtime(void) const {
120 uint16_t days = date2days(yOff, m, d);
121 t = time2long(days, hh, mm, ss);
122 t += SECONDS_FROM_1970_TO_2000; // seconds from 1970 to 2000
127 ////////////////////////////////////////////////////////////////////////////////
128 // RTC_DS1307 implementation
130 static uint8_t bcd2bin (uint8_t val) { return val - 6 * (val >> 4); }
131 static uint8_t bin2bcd (uint8_t val) { return val + 6 * (val / 10); }
133 uint8_t RTC_DS1307::begin(void) {
140 uint8_t RTC_DS1307::isrunning(void) {
141 Wire.beginTransmission(DS1307_ADDRESS);
143 Wire.endTransmission();
145 Wire.requestFrom(DS1307_ADDRESS, 1);
146 uint8_t ss = Wire.read();
150 void RTC_DS1307::adjust(const DateTime& dt) {
151 Wire.beginTransmission(DS1307_ADDRESS);
153 Wire.write(bin2bcd(dt.second()));
154 Wire.write(bin2bcd(dt.minute()));
155 Wire.write(bin2bcd(dt.hour()));
156 Wire.write(bin2bcd(0));
157 Wire.write(bin2bcd(dt.day()));
158 Wire.write(bin2bcd(dt.month()));
159 Wire.write(bin2bcd(dt.year() - 2000));
161 Wire.endTransmission();
164 DateTime RTC_DS1307::now() {
165 Wire.beginTransmission(DS1307_ADDRESS);
167 Wire.endTransmission();
169 Wire.requestFrom(DS1307_ADDRESS, 7);
170 uint8_t ss = bcd2bin(Wire.read() & 0x7F);
171 uint8_t mm = bcd2bin(Wire.read());
172 uint8_t hh = bcd2bin(Wire.read());
174 uint8_t d = bcd2bin(Wire.read());
175 uint8_t m = bcd2bin(Wire.read());
176 uint16_t y = bcd2bin(Wire.read()) + 2000;
178 return DateTime (y, m, d, hh, mm, ss);
183 uint8_t RTC_DS1307::isrunning(void) {
184 Wire.beginTransmission(DS1307_ADDRESS);
186 Wire.endTransmission();
188 Wire.requestFrom(DS1307_ADDRESS, 1);
189 uint8_t ss = Wire.receive();
193 void RTC_DS1307::adjust(const DateTime& dt) {
194 Wire.beginTransmission(DS1307_ADDRESS);
196 Wire.send(bin2bcd(dt.second()));
197 Wire.send(bin2bcd(dt.minute()));
198 Wire.send(bin2bcd(dt.hour()));
199 Wire.send(bin2bcd(0));
200 Wire.send(bin2bcd(dt.day()));
201 Wire.send(bin2bcd(dt.month()));
202 Wire.send(bin2bcd(dt.year() - 2000));
204 Wire.endTransmission();
207 DateTime RTC_DS1307::now() {
208 Wire.beginTransmission(DS1307_ADDRESS);
210 Wire.endTransmission();
212 Wire.requestFrom(DS1307_ADDRESS, 7);
213 uint8_t ss = bcd2bin(Wire.receive() & 0x7F);
214 uint8_t mm = bcd2bin(Wire.receive());
215 uint8_t hh = bcd2bin(Wire.receive());
217 uint8_t d = bcd2bin(Wire.receive());
218 uint8_t m = bcd2bin(Wire.receive());
219 uint16_t y = bcd2bin(Wire.receive()) + 2000;
221 return DateTime (y, m, d, hh, mm, ss);
227 ////////////////////////////////////////////////////////////////////////////////
228 // RTC_Millis implementation
230 long RTC_Millis::offset = 0;
232 void RTC_Millis::adjust(const DateTime& dt) {
233 offset = dt.unixtime() - millis() / 1000;
236 DateTime RTC_Millis::now() {
237 return (uint32_t)(offset + millis() / 1000);
240 ////////////////////////////////////////////////////////////////////////////////