Adding support for SAM

Author: mikaelpatel

README.md

@@ -4,7 +4,7 @@ The RTC library has been developed to allow a common interface for RTC
 devices. The library includes a software based RTC, and device drivers
 for DS1302 and DS1307 Real-Time Clock devices.
 
-Version: 1.0
+Version: 1.1
 
 ## Classes
 

examples/RTC/RTC.ino

@@ -23,10 +23,9 @@ DS1302<BOARD::D11, BOARD::D12, BOARD::D13> rtc;
 Software::TWI<BOARD::D18, BOARD::D19> twi;
 #else
 // Configure: Hardware TWI bus clock frequency (100 or 400 kHz)
-#define FREQ 100000UL
-// #define FREQ 400000UL
 #include "Hardware/TWI.h"
-Hardware::TWI twi(FREQ);
+Hardware::TWI twi(100000UL);
+// Hardware::TWI twi(400000UL);
 #endif
 DS1307 rtc(twi);
 

library.properties

@@ -1,9 +1,9 @@
 name=Arduino-RTC
-version=1.0
+version=1.1
 author=Mikael Patel
 maintainer=Mikael Patel <mikael.patel@gmail.com>
 sentence=Real-Time Clock (RTC) library for Arduino.
 paragraph=The RTC library has been developed to allow a common interface for RTC devices. The library also includes a simple software RTC based on the Arduino milliseconds function, and device drivers for DS1302 and DS1307.
 category=Communication
 url=https://github.com/mikaelpatel/Arduino-RTC
-architectures=avr
+architectures=avr,sam

mainpage.dox

@@ -5,7 +5,7 @@ devices. The library also includes a simple software RTC based on the
 Arduino milliseconds function, and device drivers for DS1302 and
 DS1307.
 
-Version: 1.0
+Version: 1.1
 */
 
 /** @page License

src/Driver/DS1302.h

@@ -20,8 +20,7 @@
 #define DS1302_H
 
 #include "GPIO.h"
-#include "bcd.h"
-#include "time.h"
+#include "RTC.h"
 
 #ifndef CHARBITS
 #define CHARBITS 8

src/Driver/DS1307.h

@@ -19,8 +19,7 @@
 #ifndef DS1307_H
 #define DS1307_H
 
-#include "bcd.h"
-#include "time.h"
+#include "RTC.h"
 #include "TWI.h"
 
 /**

src/Hardware/AVR/RTC.h

@@ -0,0 +1,103 @@
+/**
+ * @file Hardware/AVR/RTC.h
+ * @version 1.0
+ *
+ * @section License
+ * Copyright (C) 2017, Mikael Patel
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ */
+
+#ifndef HARDWARE_AVR_RTC_H
+#define HARDWARE_AVR_RTC_H
+
+/**
+ * Software Real-Time Clock.
+ */
+class RTC {
+public:
+  /**
+   * Construct software real-time clock based on millis().
+   */
+  RTC() :
+    m_millis(0),
+    m_time(0)
+  {}
+
+  /**
+   * Increment seconds counter when time has elapsed.
+   * Return true(1) if an increment occured, otherwise false(0).
+   */
+  bool tick()
+  {
+    uint16_t now = millis();
+    if (now - m_millis < 1000) return (false);
+    uint8_t sreg = SREG;
+    __asm__ __volatile__("cli" ::: "memory");
+    m_time += 1;
+    m_millis = now;
+    SREG = sreg;
+    __asm__ __volatile__("" ::: "memory");
+    return (true);
+  }
+
+  /**
+   * Return the current time in seconds from epoch.
+   */
+  time_t get_time()
+  {
+    uint8_t sreg = SREG;
+    __asm__ __volatile__("cli" ::: "memory");
+    time_t res = m_time;
+    SREG = sreg;
+    __asm__ __volatile__("" ::: "memory");
+    return (res);
+  }
+
+  /**
+   * Set the current time (seconds) from epoch.
+   */
+  void set_time(time_t time)
+  {
+    uint8_t sreg = SREG;
+    __asm__ __volatile__("cli" ::: "memory");
+    m_time = time;
+    SREG = sreg;
+    __asm__ __volatile__("" ::: "memory");
+  }
+
+  /**
+   * Return the current time as a time structure.
+   */
+  void get_time(struct tm& now)
+  {
+    time_t time = get_time();
+    gmtime_r(&time, &now);
+  }
+
+  /**
+   * Set the current time based on the given time structure.
+   */
+  void set_time(struct tm& now)
+  {
+    extern long __utc_offset;
+    set_time(mktime(&now) + __utc_offset);
+  }
+
+protected:
+  /** Timestamp for previous tick call. */
+  volatile uint16_t m_millis;
+
+  /** Current time from epoch. */
+  volatile time_t m_time;
+};
+
+#endif

src/time/difftime.cpp renamed to src/Hardware/AVR/difftime.cpp

@@ -26,7 +26,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <time.h>
+#include "time.h"
 
 int32_t
 difftime(time_t t1, time_t t2)

src/eu_dst.h renamed to src/Hardware/AVR/eu_dst.h

@@ -51,8 +51,7 @@
 #ifndef EU_DST_H
 #define EU_DST_H
 
-#include <time.h>
-#include <inttypes.h>
+#include "time.h"
 
 int eu_dst(const time_t* timer, int32_t* z)
 {

src/time/gmtime_r.cpp renamed to src/Hardware/AVR/gmtime_r.cpp

@@ -26,9 +26,8 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <time.h>
+#include "time.h"
 #include <stdlib.h>
-#include <inttypes.h>
 
 struct tm*
 gmtime_r(const time_t * timer, struct tm * timeptr)