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
Fork of DS1307 by
ds1307.cpp
- Committer:
- Michielber
- Date:
- 2014-12-04
- Revision:
- 1:6a504db47332
- Parent:
- 0:c3e4da8feb10
File content as of revision 1:6a504db47332:
#include "ds1307.h" DS1307::DS1307(PinName sda, PinName scl ) : ds1307i2c(sda,scl) { ds1307i2c.frequency(DS1307_freq); } DS1307::~DS1307() { } int DS1307::read( int addr, int quantity, char *data) { // note the char array at data must contain 63 locations or unpredictable behavior will happen // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access // quantity must be 1 - 63 as the 64th ram location is clobered in this method of access int test = 0 ; char temp_data[65]; if (addr > DS1307_lastram) return (1); // fail because address greater then what chip has to read from if (addr < 0 ) return (1); // fail because address less then 0 is not available if (quantity > DS1307_lastreg) return (1); // fail because quantity greater then what can be read if ((addr + quantity) > DS1307_lastreg ) return (1); // fail because cant read past reg 63 if ( quantity == 0 ) return (1); // fail because zero quantity wanted temp_data[0] = DS1307_lastreg ; // note this ram location is used to set the addressing pointer in DS1307 temp_data[1] = 0; // just junk to clober this address with test = ds1307i2c.write(DS1307_addr,temp_data,2); if (test == 1) return (1); // the write operation failed ds1307i2c.stop(); // now the DS1307 is pointing to the first register if ( addr != 0 ) test = ds1307i2c.read(DS1307_addr,temp_data,addr); // now the DS1307 address pointer is pointing to correct address if (test == 1) return (1); // the read operation failed test = ds1307i2c.read(DS1307_addr,data,quantity); // read the DS1307 registers now if (test == 1) return (1); // read operation failed return(0); // looks like the data read was good } int DS1307::read(int addr, int *data) { // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access int test = 0; char temp_data[65]; test = DS1307::read(addr, 1, &temp_data[0]); if (test == 1) return(1); // fail because read to DS1307 failed *data = (int)temp_data[0]; // returing the read data by pointer return (0); // the single read is successfull } int DS1307::write( int addr, int quantity, char *data) { // note the char array at data must contain 63 locations or unpredictable behavior will happen // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access // quantity must be 1 - 63 as the 64th ram location is clobered in this method of access int test = 0 ; char temp_data[65] ; int loop = 0; if (addr > DS1307_lastram) return (1); // fail because address greater then what chip has to read from if (addr < 0 ) return (1); // fail because address less then 0 is not available if (quantity > DS1307_lastreg) return (1); // fail because quantity greater then what can be read if (quantity == 0) return (1); // fail because zero quantity is wanted if ((addr + quantity) > DS1307_lastreg ) return (1); // fail because cant read past reg 63 temp_data[0] = (char)addr; for ( ; loop < quantity ; loop++ ) { temp_data[loop+1] = *(data + loop); } test = ds1307i2c.write(DS1307_addr, temp_data, (quantity + 1)); ds1307i2c.stop(); return(test); // 0 for success 1 for failure to write } int DS1307::write( int addr, int data ) { // addr must be 0 - 62 as the 64th(or 63rd as indexed from 0) ram location is clobered in this method of access int test = 0 ; char temp_data[2] ; temp_data[0] = (char)addr; temp_data[1] = (char)data; if (addr > DS1307_lastram) return (1); // fail because address greater then what chip has to read from if (addr < 0 ) return (1); // fail because address less then 0 is not available test = ds1307i2c.write(DS1307_addr, temp_data, 2); ds1307i2c.stop(); return(test); } int DS1307::start_clock(void) { // start the clock int test = 0; int junk = 0; test = DS1307::read(DS1307_sec, &junk); if (test == 1) return(1); // fail because read to DS1307 failed junk = ( 0x7F & junk); // basicaly i mask bit 8 to set it to zero test = DS1307::write(DS1307_sec,junk); // now write the seconds back to register and because bit 8 is zero this starts clock. if (test == 1) return(1); // fail because read to DS1307 failed return(test); // } int DS1307::stop_clock(void) { // stop clock int test = 0; int junk = 0; test = DS1307::read(DS1307_sec, &junk); if (test == 1) return(1); // fail because read to DS1307 failed junk = ( 0x7F & junk); // basicaly i mask bit 8 to set it to zero but keep all other bits junk = ( 0x80 | junk); // basicaly i mask bit 8 to set it to one test = DS1307::write(DS1307_sec,junk); // now write the seconds back to register and because bit 8 is one this starts clock. if (test == 1) return(1); // fail because read to DS1307 failed return(test); // } int DS1307::twelve_hour(void) { // set 12 hour mode int test = 0; int junk = 0; test = DS1307::read(DS1307_hour, &junk); if (test == 1) return(1); // fail because read to DS1307 failed if ((junk & 0x40) == 0x40) return(0); // return because 12 mode is active now all done! junk = ( junk & 0x3F); // only use 24 hour time values if (junk == 0x00) junk = 0x12; else if (junk >= 0x13) if (junk < 0x20) { junk = junk - 0x12; junk = (junk | 0x20); // add back the pm indicator } else switch (junk) { case 0x20: junk = 0x28; break; case 0x21: junk = 0x29; break; case 0x22: junk = 0x30; break; case 0x23: junk = 0x31; break; } test = DS1307::write(DS1307_hour,(0x40 | junk)); // set bit 6 with the new 12 hour time converted from the 24 hour time if (test == 1) return(1); // fail because read to DS1307 failed return(0); } int DS1307::twentyfour_hour(void) { // set 24 hour mode int test = 0; int junk = 0; test = DS1307::read(DS1307_hour, &junk); if (test == 1) return(1); // fail because read to DS1307 failed if ((junk & 0x40) == 0) return(0); // return because 24 mode is active now all done! junk = (junk & 0xBF); // get value bits and am/pm indicator bit but drop 12/24 hour bit if (junk > 0x12) if ( junk <= 0x27 ) junk = junk - 0x0E; else junk = junk - 0x08; test = DS1307::write(DS1307_hour,( 0xBF & junk)); // clear bit 6 and set the new 24 hour time converted from 12 hour time if (test == 1) return(1); // fail because read to DS1307 failed return(0); } 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 // 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) DS1307::stop_clock(); if (1 == DS1307::hilow_check( 59, 0, sec)) { return(1); // failed because recieved value is not in bounds } else { if (1 == (DS1307::write(DS1307_sec,DS1307::dectobcd(sec)))) return(1); // failed to write for some reason } if (1 == DS1307::hilow_check( 59, 0, min)) { return(1); // failed because recieved value is not in bounds } else { if (1 == (DS1307::write(DS1307_min,DS1307::dectobcd(min)))) return(1); // failed to write for some reason } if (1 == DS1307::twentyfour_hour()) return(1); // failed to set 24 hour format 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 return(1); // failed because recieved value is not in bounds } else { if (1 == (DS1307::write(DS1307_hour,DS1307::dectobcd(hour)))) return(1); // failed to write for some reason } if (1 == DS1307::twentyfour_hour()) return(1); // failed to set 24 hour format if (1 == DS1307::hilow_check( 7, 1, day)) { return(1); // failed because recieved value is not in bounds } else { if (1 == (DS1307::write(DS1307_day,DS1307::dectobcd(day)))) return(1); // failed to write for some reason } if (1 == DS1307::hilow_check( 31, 1, date)) { return(1); // failed because recieved value is not in bounds } else { if (1 == (DS1307::write(DS1307_date,DS1307::dectobcd(date)))) return(1); // failed to write for some reason } if (1 == DS1307::hilow_check( 12, 1, month)) { return(1); // failed because recieved value is not in bounds } else { if (1 == (DS1307::write(DS1307_month,DS1307::dectobcd(month)))) return(1); // failed to write for some reason } if (1 == DS1307::hilow_check( 99, 0, year)) { return(1); // failed because recieved value is not in bounds } else { if (1 == (DS1307::write(DS1307_year,DS1307::dectobcd(year)))) return(1); // failed to write for some reason } DS1307::start_clock(); return (0); // time is now set } int DS1307::gettime(int *sec, int *min, int *hour, int *day, int *date, int *month, int *year) { // to get the current time information // 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) if (1 == DS1307::read(DS1307_sec,sec)) return(1); // failed to read for some reason *sec = (*sec & 0x7F ); // drop the clock start stop bit *sec = DS1307::bcdtodec( *sec); // bcd is now dec value if (1 == DS1307::read(DS1307_min,min)) return(1); // failed to read for some reason *min = (*min & 0x7F ); // drop bit 7 because it should be 0 anyways *min = DS1307::bcdtodec( *min); // bcd is now dec value if (1 == DS1307::read(DS1307_hour,hour)) return(1); // failed to read for some reason 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 if (1 == DS1307::twentyfour_hour()) return(1); // failed to set 24 hour mode for some reason if (1 == DS1307::read(DS1307_hour,hour)) return(1); // failed to read for some reason *hour = (*hour & 0x3F ); // drop bit 7 & 6 they are not used for 24 hour mode reading *hour = DS1307::bcdtodec( *hour); // bcd is now dec value if (1 == DS1307::twelve_hour()) return(1); // failed to return to 12 hour mode for some reason } else { // in 24 hour mode already so just read the hour value if (1 == DS1307::read(DS1307_hour,hour)) return(1); // failed to read for some reason *hour = (*hour & 0x3F ); // drop bit 7 & 6 they are not used for 24 hour mode reading *hour = DS1307::bcdtodec( *hour); // bcd is now dec value } if (1 == DS1307::read(DS1307_day,day)) return(1); // failed to read for some reason *day = (*day & 0x07 ); // drop the non used bits *day = DS1307::bcdtodec( *day); // bcd is now dec value if (1 == DS1307::read(DS1307_date,date)) return(1); // failed to read for some reason *date = (*date & 0x3F ); // drop bit 6 and 7 not used for date value *date = DS1307::bcdtodec( *date); // bcd is now dec value if (1 == DS1307::read(DS1307_month,month)) return(1); // failed to read for some reason *month = (*month & 0x1F ); // drop bit 5, 6 and 7 not used for month value *month = DS1307::bcdtodec( *month); // bcd is now dec value if (1 == DS1307::read(DS1307_year,year)) return(1); // failed to read for some reason *year = DS1307::bcdtodec( *year); // bcd is now dec value return (0); // data returned is valid } int DS1307::dectobcd( int dec) { int low = 0; int high = 0; high = dec / 10; // this gives the high nibble value low = dec - (high * 10); // this gives the lower nibble value return ((high *16) + low); // this is the final bcd value but in interger format } int DS1307::bcdtodec( int bcd) { int low = 0; int high = 0; high = bcd / 16; low = bcd - (high * 16); return ((high * 10) + low); } int DS1307::hilow_check( int hi, int low, int value) { if ((value >= low)&(value <= hi)) return(0); // value is equal to or inbetween hi and low else return(1); // value is not equal to or inbetween hi and low }