ds1337.cpp

00001 #include "ds1337.h"
00002 
00003 #define TIME_LENGTH 8 //Length of buffer needed for time/date
00004 
00005 DS1337::DS1337(PinName sda, PinName scl) : _i2c(sda, scl)
00006 {
00007     _i2c.frequency(DS1337_I2C_FCY);
00008     memset(err, 0, ERR_BUFFER_LEN);
00009 }
00010 
00011 void DS1337::time2str(Time * t, char * str)
00012 {
00013     sprintf(str, "%02d/%02d/%04d-%02d:%02d:%02d",t->tm_mon, t->tm_mday,(t->tm_year+1900), t->tm_hour,t->tm_min,t->tm_sec);
00014 }
00015 
00016 bool DS1337::now(Time * now)
00017 {
00018     buffer[0] = 0x00; // memory address
00019     
00020     if (_i2c.write(DS1337_ADDR, &buffer[0], 1) != 0) 
00021     {
00022         sprintf(err, "RTC command write Failed");
00023         return false;
00024     }
00025     
00026     if (_i2c.read(DS1337_ADDR, buffer, DS1337_BUFFER_SIZE) != 0) 
00027     {
00028         sprintf(err, "RTC buffer read Failed");
00029         return false;
00030     }
00031    
00032     if (buffer[0] & 0x80) 
00033     {
00034         sprintf(err, "Clock Stopped");
00035         return false;
00036     }
00037     
00038     if (buffer[2] & 0x40) 
00039     {
00040         sprintf(err, "12hour not supported");
00041         return false;
00042     }
00043     
00044     now->tm_sec = bcdToDecimal(buffer[0] & 0x7F);
00045     now->tm_min = bcdToDecimal(buffer[1] & 0x7F);
00046     now->tm_hour = bcdToDecimal(buffer[2] & 0x3F);
00047     now->tm_wday = buffer[3] & 0x07;
00048     now->tm_mday = bcdToDecimal(buffer[4] & 0x3F);
00049     now->tm_mon = bcdToDecimal(buffer[5] & 0x1F);
00050     now->tm_year = bcdToDecimal(buffer[6] & 0xFF);
00051     
00052     return true;
00053 }
00054 
00055 bool DS1337::set_time(Time * now)
00056 {
00057     buffer[0] = 0x00; // memory address
00058     buffer[1] = decimalToBcd(now->tm_sec) & 0x7F;
00059     buffer[2] = decimalToBcd(now->tm_min) & 0x7F;
00060     buffer[3] = decimalToBcd(now->tm_hour) & 0x3F; // 24-hour format
00061     buffer[4] = now->tm_wday & 0x07;
00062     buffer[5] = decimalToBcd(now->tm_mday) & 0x3F;
00063     buffer[6] = decimalToBcd(now->tm_mon) & 0x1F;
00064     buffer[7] = decimalToBcd(now->tm_year) & 0xFF;
00065     
00066     if (_i2c.write(DS1337_ADDR, buffer, TIME_LENGTH) != 0) 
00067     {
00068         sprintf(err, "RTC command write Failed");
00069         return false;
00070     }
00071 
00072     return true;
00073 }
00074