Philip Smith
This is a class for using the DS1307 Real Time Clock chip from Dallas Semiconductor. This class uses mbeds i2c class to talk to the chip. I have tested this currently on the LPC1768 mbed device with the Spark fun breakout board from http://www.sparkfun.com/products/99
Dependents: Mbell Astromed_build20121123 Raymon_pub_ver CCRMonitor12_sp07_120ver ... more
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ds1307.cpp
00001 #include "ds1307.h" 00002 00003 DS1307::DS1307(PinName sda, PinName scl ) : ds1307i2c(sda,scl) { 00004 ds1307i2c.frequency(DS1307_freq); 00005 } 00006 00007 DS1307::~DS1307() { 00008 } 00009 00010 int DS1307::read( int addr, int quantity, char *data) { 00011 // note the char array at data must contain 63 locations or unpredictable behavior will happen 00012 // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access 00013 // quantity must be 1 - 63 as the 64th ram location is clobered in this method of access 00014 int test = 0 ; 00015 char temp_data[65]; 00016 00017 if (addr > DS1307_lastram) return (1); // fail because address greater then what chip has to read from 00018 if (addr < 0 ) return (1); // fail because address less then 0 is not available 00019 if (quantity > DS1307_lastreg) return (1); // fail because quantity greater then what can be read 00020 if ((addr + quantity) > DS1307_lastreg ) return (1); // fail because cant read past reg 63 00021 if ( quantity == 0 ) return (1); // fail because zero quantity wanted 00022 temp_data[0] = DS1307_lastreg ; // note this ram location is used to set the addressing pointer in DS1307 00023 temp_data[1] = 0; // just junk to clober this address with 00024 test = ds1307i2c.write(DS1307_addr,temp_data,2); 00025 if (test == 1) return (1); // the write operation failed 00026 ds1307i2c.stop(); // now the DS1307 is pointing to the first register 00027 if ( addr != 0 ) test = ds1307i2c.read(DS1307_addr,temp_data,addr); // now the DS1307 address pointer is pointing to correct address 00028 if (test == 1) return (1); // the read operation failed 00029 test = ds1307i2c.read(DS1307_addr,data,quantity); // read the DS1307 registers now 00030 if (test == 1) return (1); // read operation failed 00031 return(0); // looks like the data read was good 00032 } 00033 00034 int DS1307::read(int addr, int *data) { 00035 // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access 00036 int test = 0; 00037 char temp_data[65]; 00038 test = DS1307::read(addr, 1, &temp_data[0]); 00039 if (test == 1) return(1); // fail because read to DS1307 failed 00040 *data = (int)temp_data[0]; // returing the read data by pointer 00041 return (0); // the single read is successfull 00042 } 00043 00044 int DS1307::write( int addr, int quantity, char *data) { 00045 // note the char array at data must contain 63 locations or unpredictable behavior will happen 00046 // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access 00047 // quantity must be 1 - 63 as the 64th ram location is clobered in this method of access 00048 int test = 0 ; 00049 char temp_data[65] ; 00050 int loop = 0; 00051 00052 if (addr > DS1307_lastram) return (1); // fail because address greater then what chip has to read from 00053 if (addr < 0 ) return (1); // fail because address less then 0 is not available 00054 if (quantity > DS1307_lastreg) return (1); // fail because quantity greater then what can be read 00055 if (quantity == 0) return (1); // fail because zero quantity is wanted 00056 if ((addr + quantity) > DS1307_lastreg ) return (1); // fail because cant read past reg 63 00057 00058 temp_data[0] = (char)addr; 00059 for ( ; loop < quantity ; loop++ ) { 00060 temp_data[loop+1] = *(data + loop); 00061 } 00062 test = ds1307i2c.write(DS1307_addr, temp_data, (quantity + 1)); 00063 ds1307i2c.stop(); 00064 return(test); // 0 for success 1 for failure to write 00065 } 00066 00067 int DS1307::write( int addr, int data ) { 00068 // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access 00069 int test = 0 ; 00070 char temp_data[2] ; 00071 00072 temp_data[0] = (char)addr; 00073 temp_data[1] = (char)data; 00074 if (addr > DS1307_lastram) return (1); // fail because address greater then what chip has to read from 00075 if (addr < 0 ) return (1); // fail because address less then 0 is not available 00076 test = ds1307i2c.write(DS1307_addr, temp_data, 2); 00077 ds1307i2c.stop(); 00078 return(test); 00079 } 00080 00081 int DS1307::start_clock(void) { // start the clock 00082 int test = 0; 00083 int junk = 0; 00084 00085 test = DS1307::read(DS1307_sec, &junk); 00086 if (test == 1) return(1); // fail because read to DS1307 failed 00087 junk = ( 0x7F & junk); // basicaly i mask bit 8 to set it to zero 00088 test = DS1307::write(DS1307_sec,junk); // now write the seconds back to register and because bit 8 is zero this starts clock. 00089 if (test == 1) return(1); // fail because read to DS1307 failed 00090 return(test); // 00091 } 00092 00093 int DS1307::stop_clock(void) { // stop clock 00094 int test = 0; 00095 int junk = 0; 00096 00097 test = DS1307::read(DS1307_sec, &junk); 00098 if (test == 1) return(1); // fail because read to DS1307 failed 00099 junk = ( 0x7F & junk); // basicaly i mask bit 8 to set it to zero but keep all other bits 00100 junk = ( 0x80 | junk); // basicaly i mask bit 8 to set it to one 00101 test = DS1307::write(DS1307_sec,junk); // now write the seconds back to register and because bit 8 is one this starts clock. 00102 if (test == 1) return(1); // fail because read to DS1307 failed 00103 return(test); // 00104 } 00105 00106 int DS1307::twelve_hour(void) { // set 12 hour mode 00107 int test = 0; 00108 int junk = 0; 00109 00110 test = DS1307::read(DS1307_hour, &junk); 00111 if (test == 1) return(1); // fail because read to DS1307 failed 00112 if ((junk & 0x40) == 0x40) return(0); // return because 12 mode is active now all done! 00113 00114 junk = ( junk & 0x3F); // only use 24 hour time values 00115 if (junk == 0x00) 00116 junk = 0x12; 00117 else if (junk >= 0x13) 00118 if (junk < 0x20) { 00119 junk = junk - 0x12; 00120 junk = (junk | 0x20); // add back the pm indicator 00121 } else 00122 switch (junk) { 00123 case 0x20: 00124 junk = 0x28; 00125 break; 00126 case 0x21: 00127 junk = 0x29; 00128 break; 00129 case 0x22: 00130 junk = 0x30; 00131 break; 00132 case 0x23: 00133 junk = 0x31; 00134 break; 00135 } 00136 00137 test = DS1307::write(DS1307_hour,(0x40 | junk)); // set bit 6 with the new 12 hour time converted from the 24 hour time 00138 if (test == 1) return(1); // fail because read to DS1307 failed 00139 00140 return(0); 00141 } 00142 00143 int DS1307::twentyfour_hour(void) { // set 24 hour mode 00144 int test = 0; 00145 int junk = 0; 00146 00147 test = DS1307::read(DS1307_hour, &junk); 00148 if (test == 1) return(1); // fail because read to DS1307 failed 00149 if ((junk & 0x40) == 0) return(0); // return because 24 mode is active now all done! 00150 00151 junk = (junk & 0xBF); // get value bits and am/pm indicator bit but drop 12/24 hour bit 00152 00153 if (junk > 0x12) 00154 if ( junk <= 0x27 ) 00155 junk = junk - 0x0E; 00156 else 00157 junk = junk - 0x08; 00158 00159 test = DS1307::write(DS1307_hour,( 0xBF & junk)); // clear bit 6 and set the new 24 hour time converted from 12 hour time 00160 if (test == 1) return(1); // fail because read to DS1307 failed 00161 00162 return(0); 00163 } 00164 00165 int DS1307::settime(int sec, int min, int hour, int day, int date, int month, int year) { // to set the current time and start clock 00166 // sec = 0 to 59, min = 0 to 59, hours = 0 to 23 ( 24 hour mode only ), day = 1 to 7 ( day of week ), date = 1 to 31, month = 1 to 12, year 0 to 99 ( this is for 2000 to 2099) 00167 DS1307::stop_clock(); 00168 00169 if (1 == DS1307::hilow_check( 59, 0, sec)) { 00170 return(1); // failed because recieved value is not in bounds 00171 } else { 00172 if (1 == (DS1307::write(DS1307_sec,DS1307::dectobcd(sec)))) return(1); // failed to write for some reason 00173 } 00174 00175 if (1 == DS1307::hilow_check( 59, 0, min)) { 00176 return(1); // failed because recieved value is not in bounds 00177 } else { 00178 if (1 == (DS1307::write(DS1307_min,DS1307::dectobcd(min)))) return(1); // failed to write for some reason 00179 } 00180 00181 if (1 == DS1307::twentyfour_hour()) return(1); // failed to set 24 hour format 00182 if (1 == DS1307::hilow_check( 23, 0, hour)) { // note setting 24 hour mode befor and after writing the hour value ensures 24 hour mode is set 00183 return(1); // failed because recieved value is not in bounds 00184 } else { 00185 if (1 == (DS1307::write(DS1307_hour,DS1307::dectobcd(hour)))) return(1); // failed to write for some reason 00186 } 00187 if (1 == DS1307::twentyfour_hour()) return(1); // failed to set 24 hour format 00188 00189 if (1 == DS1307::hilow_check( 7, 1, day)) { 00190 return(1); // failed because recieved value is not in bounds 00191 } else { 00192 if (1 == (DS1307::write(DS1307_day,DS1307::dectobcd(day)))) return(1); // failed to write for some reason 00193 } 00194 00195 if (1 == DS1307::hilow_check( 31, 1, date)) { 00196 return(1); // failed because recieved value is not in bounds 00197 } else { 00198 if (1 == (DS1307::write(DS1307_date,DS1307::dectobcd(date)))) return(1); // failed to write for some reason 00199 } 00200 00201 if (1 == DS1307::hilow_check( 12, 1, month)) { 00202 return(1); // failed because recieved value is not in bounds 00203 } else { 00204 if (1 == (DS1307::write(DS1307_month,DS1307::dectobcd(month)))) return(1); // failed to write for some reason 00205 } 00206 00207 if (1 == DS1307::hilow_check( 99, 0, year)) { 00208 return(1); // failed because recieved value is not in bounds 00209 } else { 00210 if (1 == (DS1307::write(DS1307_year,DS1307::dectobcd(year)))) return(1); // failed to write for some reason 00211 } 00212 00213 DS1307::start_clock(); 00214 return (0); // time is now set 00215 } 00216 00217 int DS1307::gettime(int *sec, int *min, int *hour, int *day, int *date, int *month, int *year) { // to get the current time information 00218 // sec = 0 to 59, min = 0 to 59, hours = 0 to 23 ( 24 hour mode only ), day = 1 to 7 ( day of week ), date = 1 to 31, month = 1 to 12, year 0 to 99 ( this is for 2000 to 2099) 00219 if (1 == DS1307::read(DS1307_sec,sec)) return(1); // failed to read for some reason 00220 *sec = (*sec & 0x7F ); // drop the clock start stop bit 00221 *sec = DS1307::bcdtodec( *sec); // bcd is now dec value 00222 00223 if (1 == DS1307::read(DS1307_min,min)) return(1); // failed to read for some reason 00224 *min = (*min & 0x7F ); // drop bit 7 because it should be 0 anyways 00225 *min = DS1307::bcdtodec( *min); // bcd is now dec value 00226 00227 if (1 == DS1307::read(DS1307_hour,hour)) return(1); // failed to read for some reason 00228 if ((*hour & 0x40) == 0x40) { // if true then 12 hour mode is set currently so change to 24 hour, read value, and return to 12 hour mode 00229 if (1 == DS1307::twentyfour_hour()) return(1); // failed to set 24 hour mode for some reason 00230 if (1 == DS1307::read(DS1307_hour,hour)) return(1); // failed to read for some reason 00231 *hour = (*hour & 0x3F ); // drop bit 7 & 6 they are not used for 24 hour mode reading 00232 *hour = DS1307::bcdtodec( *hour); // bcd is now dec value 00233 if (1 == DS1307::twelve_hour()) return(1); // failed to return to 12 hour mode for some reason 00234 } else { // in 24 hour mode already so just read the hour value 00235 if (1 == DS1307::read(DS1307_hour,hour)) return(1); // failed to read for some reason 00236 *hour = (*hour & 0x3F ); // drop bit 7 & 6 they are not used for 24 hour mode reading 00237 *hour = DS1307::bcdtodec( *hour); // bcd is now dec value 00238 } 00239 00240 if (1 == DS1307::read(DS1307_day,day)) return(1); // failed to read for some reason 00241 *day = (*day & 0x07 ); // drop the non used bits 00242 *day = DS1307::bcdtodec( *day); // bcd is now dec value 00243 00244 if (1 == DS1307::read(DS1307_date,date)) return(1); // failed to read for some reason 00245 *date = (*date & 0x3F ); // drop bit 6 and 7 not used for date value 00246 *date = DS1307::bcdtodec( *date); // bcd is now dec value 00247 00248 if (1 == DS1307::read(DS1307_month,month)) return(1); // failed to read for some reason 00249 *month = (*month & 0x1F ); // drop bit 5, 6 and 7 not used for month value 00250 *month = DS1307::bcdtodec( *month); // bcd is now dec value 00251 00252 if (1 == DS1307::read(DS1307_year,year)) return(1); // failed to read for some reason 00253 *year = DS1307::bcdtodec( *year); // bcd is now dec value 00254 00255 return (0); // data returned is valid 00256 } 00257 00258 00259 int DS1307::dectobcd( int dec) { 00260 int low = 0; 00261 int high = 0; 00262 00263 high = dec / 10; // this gives the high nibble value 00264 low = dec - (high * 10); // this gives the lower nibble value 00265 return ((high *16) + low); // this is the final bcd value but in interger format 00266 } 00267 00268 int DS1307::bcdtodec( int bcd) { 00269 int low = 0; 00270 int high = 0; 00271 00272 high = bcd / 16; 00273 low = bcd - (high * 16); 00274 return ((high * 10) + low); 00275 00276 } 00277 00278 int DS1307::hilow_check( int hi, int low, int value) { 00279 if ((value >= low)&(value <= hi)) 00280 return(0); // value is equal to or inbetween hi and low 00281 else 00282 return(1); // value is not equal to or inbetween hi and low 00283 } 00284 00285 00286 00287
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