Diff: DS1307.cpp

Revision:

0:f29e45a25cba

Child:

1:60383faa35a9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS1307.cpp	Fri Apr 25 18:15:47 2014 +0000
@@ -0,0 +1,88 @@
+#include "mbed.h"
+#include "DS1307.h"
+
+
+const char *DS1307::m_weekDays[] = { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" };
+
+#define DS1307_ADDR 0xd0
+
+
+DS1307::DS1307(PinName sda, PinName scl)
+{
+    // create a new I2C object
+    m_rtc = new I2C(sda, scl);
+    if (m_rtc == NULL) error("DS1307");
+        
+    // set the frequency to standard 100kHz
+    m_rtc->frequency(100000);
+}
+
+
+DS1307::~DS1307()
+{
+    if (m_rtc != NULL) delete m_rtc;
+}
+
+
+bool DS1307::read(int address, char *buffer, int len)
+{
+    char data[1] = { (char)address };
+
+    if (m_rtc->write(DS1307_ADDR, data, 1) != 0) return false;
+    if (m_rtc->read(DS1307_ADDR, buffer, len) != 0) return false;
+
+    return true;
+}
+
+
+bool DS1307::write(int address, char *buffer, int len)
+{
+    char data[9] = { (char)address };
+
+    if (len > 8) return false;
+    memcpy(&data[1], buffer, len);
+
+    if (m_rtc->write(DS1307_ADDR, data, len + 1) != 0) return false;
+    
+    return true;
+}
+
+
+time_t DS1307::getNow()
+{
+    struct tm now;
+    char buffer[7];
+    
+    if (!read(0, buffer, 7)) return 0;
+    if (!(buffer[2] & 0x40)) return 0; // 12-hour format not supported
+    now.tm_sec = bcdToDecimal(buffer[0] & 0x7F);
+    now.tm_min = bcdToDecimal(buffer[1]);
+    now.tm_hour = bcdToDecimal(buffer[2] & 0x3F);
+    now.tm_wday = buffer[3]; 
+    now.tm_mday = bcdToDecimal(buffer[4]);
+    now.tm_mon = bcdToDecimal(buffer[5]) - 1;
+    now.tm_year = bcdToDecimal(buffer[6]) + 2000 - 1900;
+    
+    return mktime(&now);
+}
+
+
+bool DS1307::setNow(time_t t)
+{
+    struct tm *now;
+    char buffer[8];
+
+    now = localtime(&t);
+
+    buffer[0] = decimalToBcd(now->tm_sec) & 0x7f; // CH = 0
+    buffer[1] = decimalToBcd(now->tm_min);
+    buffer[2] = 0x40 | (decimalToBcd(now->tm_hour) & 0x3F); // 24-hour format
+    buffer[3] = now->tm_wday + 1;
+    buffer[4] = decimalToBcd(now->tm_mday);
+    buffer[5] = decimalToBcd(now->tm_mon+1);
+    buffer[6] = decimalToBcd(now->tm_year + 1900 - 2000);
+    buffer[7] = 0x00; // OUT = 0
+    if (!write(0, buffer, 8)) return false;
+
+    return true;
+}