Diff: DS1307.cpp

Revision:

0:7f90c8e04249

Child:

1:2c4e81ecda67

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS1307.cpp	Tue Jul 17 05:49:20 2012 +0000
@@ -0,0 +1,75 @@
+// Code by JeeLabs http://news.jeelabs.org/code/
+// Released to the public domain! Enjoy!
+
+/*
+ * Taken from https://github.com/adafruit/RTClib
+ * and modified for LPC1768 by Neal Horman July 2012
+ */
+
+#include "mbed.h"
+#include "DS1307.h"
+
+#define DS1307_ADDRESS 0xD0
+
+////////////////////////////////////////////////////////////////////////////////
+// RtcDs1307 implementation
+
+static uint8_t bcd2bin (uint8_t val) { return val - 6 * (val >> 4); }
+static uint8_t bin2bcd (uint8_t val) { return val + 6 * (val / 10); }
+
+RtcDs1307::RtcDs1307(I2C &i2c) : mI2c(i2c)
+{
+    mRam[0]=8;
+    if(mI2c.write(DS1307_ADDRESS,(const char *)&mRam[0],1,true) == 0)
+        mI2c.read(DS1307_ADDRESS,(char *)&mRam[1],sizeof(mRam)-1);
+    else
+        memset(mRam,0,sizeof(mRam));
+}
+
+bool RtcDs1307::commit()
+{
+    mRam[0] = 8; // device register address 
+    return (mI2c.write(DS1307_ADDRESS,(const char *)mRam,sizeof(mRam)) == 0);
+}
+
+bool RtcDs1307::isRunning()
+{   uint8_t i = 0;
+    
+    return (mI2c.write(DS1307_ADDRESS,(const char *)&i,sizeof(i),true) == 0
+        && mI2c.read(DS1307_ADDRESS,(char *)&i,sizeof(i)) == 0
+        && (i&0x80) == 0
+        );
+}
+
+bool RtcDs1307::adjust(const DateTime& dt)
+{   uint8_t buf[9] =
+    {
+        0 // device register address
+        ,bin2bcd(dt.second()&0x7F) // make sure bit 7 (CH - Clock Halt) is off or the clock will be stopped
+        ,bin2bcd(dt.minute())
+        ,bin2bcd(dt.hour()&0x3F) // force 24h mode
+        ,bin2bcd(0)
+        ,bin2bcd(dt.day())
+        ,bin2bcd(dt.month())
+        ,bin2bcd(dt.year() - 2000)
+        ,0 // turn off SQWO
+    };
+        
+    return (mI2c.write(DS1307_ADDRESS,(const char *)buf,sizeof(buf)) == 0);
+}
+
+DateTime RtcDs1307::now()
+{   uint8_t buf[7] = {0};
+    
+    if(mI2c.write(DS1307_ADDRESS,(const char *)&buf[0],1,true) == 0)
+        mI2c.read(DS1307_ADDRESS,(char *)buf,sizeof(buf));
+
+    return DateTime (
+        bcd2bin(buf[6]) + 2000 // y
+        ,bcd2bin(buf[5]) // m
+        ,bcd2bin(buf[4]) // d
+        ,bcd2bin(buf[2] & 0x3F) // hh - mask off 24h mode
+        ,bcd2bin(buf[1]) // mm
+        ,bcd2bin(buf[0] & 0x7F) // ss - mask off CH - Clock Halt
+        );
+}
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