DS1302.cpp

00001 #include "DS1302.h"
00002 
00003 DS1302::DS1302(PinName SCLK, PinName IO, PinName CE) : _SCLK(SCLK), _IO(IO), _CE(CE)
00004 {
00005     _CE = 0;
00006     _SCLK = 0;
00007     _IO.input();
00008     writeProtect = true;
00009 }
00010 
00011 void DS1302::set_time(time_t t)
00012 {
00013     struct tm *_t = localtime(&t);
00014     writeReg(Seconds, (_t->tm_sec % 10) + ((_t->tm_sec / 10) << 4));
00015     writeReg(Minutes, (_t->tm_min % 10) + ((_t->tm_min / 10) << 4));
00016     writeReg(Hours, (_t->tm_hour % 10) + ((_t->tm_hour / 10) << 4));
00017     writeReg(Dates, (_t->tm_mday % 10) + ((_t->tm_mday / 10) << 4));
00018     writeReg(Months, ((_t->tm_mon + 1) % 10) + (((_t->tm_mon + 1) / 10) << 4));
00019     writeReg(Days, _t->tm_wday + 1);
00020     writeReg(Years, ((_t->tm_year - 100) % 10) + (((_t->tm_year - 100) / 10) << 4));
00021 }
00022 
00023 time_t DS1302::time(time_t  *t)
00024 {
00025     char regs[7];
00026     _CE = 1;
00027     wait_us(4);
00028     writeByte(ClockBurst | 1);
00029     for (int i = 0; i<7; i++)
00030         regs[i] = readByte();
00031     _CE = 0;
00032 
00033     struct tm _t;
00034     _t.tm_sec = (regs[0] & 0xF) + (regs[0] >> 4) * 10;
00035     _t.tm_min = (regs[1] & 0xF) + (regs[1] >> 4) * 10;
00036     _t.tm_hour = (regs[2] & 0xF) + (regs[2] >> 4) * 10;
00037     _t.tm_mday = (regs[3] & 0xF) + (regs[3] >> 4) * 10;
00038     _t.tm_mon = (regs[4] & 0xF) + (regs[4] >> 4) * 10 - 1;
00039     _t.tm_year = (regs[6] & 0xF) + (regs[6] >> 4) * 10 + 100;
00040 
00041     // convert to timestamp and display (1256729737)
00042     return mktime(&_t);
00043 }
00044 
00045 void DS1302::storeByte(char address, char data)
00046 {
00047     if (address > 30)
00048         return;
00049     char command = RAMBase + (address << 1);
00050     writeReg(command, data);
00051 }
00052 
00053 char DS1302::recallByte(char address)
00054 {
00055     if (address > 30)
00056         return 0;
00057     char command = RAMBase + (address << 1) + 1;
00058     return readReg(command);
00059 }
00060 
00061 char DS1302::readReg(char reg)
00062 {
00063     char retval;
00064 
00065     _CE = 1;
00066     wait_us(4);
00067     writeByte(reg);
00068     retval = readByte();
00069     wait_us(4);
00070     _CE = 0;
00071     return retval;
00072 }
00073 
00074 void DS1302::writeReg(char reg, char val)
00075 {
00076     if (writeProtect) {
00077         writeProtect = false;
00078         writeReg(WriteProtect, 0);
00079     }
00080     _CE = 1;
00081     wait_us(4);
00082     writeByte(reg);
00083     writeByte(val);
00084     wait_us(4);
00085     _CE = 0;
00086 }
00087 
00088 
00089 /*********************PRIVATE***********************/
00090 void DS1302::writeByte(char data)
00091 {
00092     _IO.output();
00093     for (int i = 0; i<8; i++) {
00094         _IO = data & 0x01;
00095         wait_us(1);
00096         _SCLK = 1;
00097         wait_us(1);
00098         _SCLK = 0;
00099         data >>= 1;
00100     }
00101     _IO.input();
00102 }
00103 
00104 char DS1302::readByte(void)
00105 {
00106     char retval = 0;
00107 
00108     _IO.input();
00109     for (int i = 0; i<8; i++) {
00110         retval |= _IO << i;
00111         wait_us(1);
00112         _SCLK = 1;
00113         wait_us(1);
00114         _SCLK = 0;
00115     }
00116     return retval;
00117 }