   uart.begin(57600);
   trace.begin(&uart, PSTR("CosaDS1307: started"));
 
-  // Check amount of free memory
-  TRACE(free_memory());
+  // Print calibration
+#if defined(RTC_CALIBRATION_MS)
+  trace << PSTR("RTC:calibration:") << RTC_CALIBRATION_MS << endl;
+#endif
+#if defined(WATCHDOG_CALIBRATION_MS)
+  trace << PSTR("Watchdog:calibration:") << WATCHDOG_CALIBRATION_MS << endl;
+#endif
 
   // Start the watchdog and internal real-time clock
   Watchdog::begin();

  trace << PSTR("control:") << bin << control << endl;
  trace.flush();

  // Synchronize clocks
  while (clkPin.is_set()) yield();
  ASSERT(rtc.get_time(now));
  now.to_binary();
  RTC::clock.time(now);
  Watchdog::clock.time(now);

  // Set calibration (from error measurement)
#if defined(RTC_CALIBRATION_MS)
  RTC::clock.calibration(RTC_CALIBRATION_MS);
#endif
#if defined(WATCHDOG_CALIBRATION_MS)
  Watchdog::clock.calibration(WATCHDOG_CALIBRATION_MS);
#endif
}

void loop()

#include "Cosa/Watchdog.hh"
#include "Cosa/Trace.hh"
#include "Cosa/IOStream/Driver/UART.hh"

// Set the real-time clock
// #define SET_TIME

// Example calibration values for internal clocks
// 1. Duemilanove Clone (Funduino 2012 May)
// #define RTC_CALIBRATION_MS 0
// #define WATCHDOG_CALIBRATION_MS -13
// 2. Leonardo (Made in Italy)
// #define RTC_CALIBRATION_MS -2
// #define WATCHDOG_CALIBRATION_MS -98
// 3. Mega 2560 Clone
// #define RTC_CALIBRATION_MS -5
// #define WATCHDOG_CALIBRATION_MS -68
// 4. Mega 2560 Clone (Funduino)
// #define RTC_CALIBRATION_MS 0
// #define WATCHDOG_CALIBRATION_MS -110
// 5. Nano Clone (DCCduino)
// #define RTC_CALIBRATION_MS 0
// #define WATCHDOG_CALIBRATION_MS -24
// 6. Pro-Mini Clone (white reset button)
// #define RTC_CALIBRATION_MS 0
// #define WATCHDOG_CALIBRATION_MS 25
// 7. Pro-Mini Clone (Deek Robot, red reset button)
// #define RTC_CALIBRATION_MS 0
// #define WATCHDOG_CALIBRATION_MS -1
// 8. Uno R3 Clone (GEtech)
// #define RTC_CALIBRATION_MS 0
// #define WATCHDOG_CALIBRATION_MS -112
// 9. Uno R3 Clone (VISduino)
// #define RTC_CALIBRATION_MS 0
// #define WATCHDOG_CALIBRATION_MS -24

// The real-time device, latest start and sample time in ram
DS1307 rtc;
