Erik - / DS1302

Library to make use of the DS1302 timekeeping IC. The functions are identical to those used by the mbed RTC's

Dependents:   temp_humid_time_DS1302_LM35_DHT11 temp_humid_light_time_DS1302_LM35_DHT11_LDR DSKY DS1302_HelloWorld ... more

HelloWorld program: https://mbed.org/users/Sissors/code/DS1302_HelloWorld/

For usage of the returned UNIX time code, see for example https://mbed.org/handbook/Time, http://www.cplusplus.com/reference/ctime/strftime/?kw=strftime and http://mbed.org/handbook/Time?action=view&revision=11592

Diff: DS1302.cpp

Revision:
0:c7cea2a415c3
diff -r 000000000000 -r c7cea2a415c3 DS1302.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS1302.cpp	Mon Mar 31 20:53:13 2014 +0000
@@ -0,0 +1,117 @@
+#include "DS1302.h"
+
+DS1302::DS1302(PinName SCLK, PinName IO, PinName CE) : _SCLK(SCLK), _IO(IO), _CE(CE)
+{
+    _CE = 0;
+    _SCLK = 0;
+    _IO.input();
+    writeProtect = true;
+}
+
+void DS1302::set_time(time_t t)
+{
+    struct tm *_t = localtime(&t);
+    writeReg(Seconds, (_t->tm_sec % 10) + ((_t->tm_sec / 10) << 4));
+    writeReg(Minutes, (_t->tm_min % 10) + ((_t->tm_min / 10) << 4));
+    writeReg(Hours, (_t->tm_hour % 10) + ((_t->tm_hour / 10) << 4));
+    writeReg(Dates, (_t->tm_mday % 10) + ((_t->tm_mday / 10) << 4));
+    writeReg(Months, ((_t->tm_mon + 1) % 10) + (((_t->tm_mon + 1) / 10) << 4));
+    writeReg(Days, _t->tm_wday + 1);
+    writeReg(Years, ((_t->tm_year - 100) % 10) + (((_t->tm_year - 100) / 10) << 4));
+}
+
+time_t DS1302::time(time_t  *t)
+{
+    char regs[7];
+    _CE = 1;
+    wait_us(4);
+    writeByte(ClockBurst | 1);
+    for (int i = 0; i<7; i++)
+        regs[i] = readByte();
+    _CE = 0;
+
+    struct tm _t;
+    _t.tm_sec = (regs[0] & 0xF) + (regs[0] >> 4) * 10;
+    _t.tm_min = (regs[1] & 0xF) + (regs[1] >> 4) * 10;
+    _t.tm_hour = (regs[2] & 0xF) + (regs[2] >> 4) * 10;
+    _t.tm_mday = (regs[3] & 0xF) + (regs[3] >> 4) * 10;
+    _t.tm_mon = (regs[4] & 0xF) + (regs[4] >> 4) * 10 - 1;
+    _t.tm_year = (regs[6] & 0xF) + (regs[6] >> 4) * 10 + 100;
+
+    // convert to timestamp and display (1256729737)
+    return mktime(&_t);
+}
+
+void DS1302::storeByte(char address, char data)
+{
+    if (address > 30)
+        return;
+    char command = RAMBase + (address << 1);
+    writeReg(command, data);
+}
+
+char DS1302::recallByte(char address)
+{
+    if (address > 30)
+        return 0;
+    char command = RAMBase + (address << 1) + 1;
+    return readReg(command);
+}
+
+char DS1302::readReg(char reg)
+{
+    char retval;
+
+    _CE = 1;
+    wait_us(4);
+    writeByte(reg);
+    retval = readByte();
+    wait_us(4);
+    _CE = 0;
+    return retval;
+}
+
+void DS1302::writeReg(char reg, char val)
+{
+    if (writeProtect) {
+        writeProtect = false;
+        writeReg(WriteProtect, 0);
+    }
+    _CE = 1;
+    wait_us(4);
+    writeByte(reg);
+    writeByte(val);
+    wait_us(4);
+    _CE = 0;
+}
+
+
+/*********************PRIVATE***********************/
+void DS1302::writeByte(char data)
+{
+    _IO.output();
+    for (int i = 0; i<8; i++) {
+        _IO = data & 0x01;
+        wait_us(1);
+        _SCLK = 1;
+        wait_us(1);
+        _SCLK = 0;
+        data >>= 1;
+    }
+    _IO.input();
+}
+
+char DS1302::readByte(void)
+{
+    char retval = 0;
+
+    _IO.input();
+    for (int i = 0; i<8; i++) {
+        retval |= _IO << i;
+        wait_us(1);
+        _SCLK = 1;
+        wait_us(1);
+        _SCLK = 0;
+    }
+    return retval;
+}
\ No newline at end of file