  *
  * @section Description
  * Demonstration of the Wireless interface and ExternalInterruptPin
- * for wakeup after power down. 
+ * for wakeup after power down. An ATtiny85-20PU running this example
+ * sketch will require 5 uA in power down mode (VWI transmitter).
  *
  * This file is part of the Arduino Che Cosa project.
  */

#include "Cosa/Watchdog.hh"
#include "Cosa/RTC.hh"

// Select Wireless device driver
// #include "Cosa/Wireless/Driver/CC1101.hh"
// CC1101 rf(0xC05A, 0x02);


#if defined(__ARDUINO_TINYX5__)
VWI rf(0xC05A, 0x03, 4000, Board::D1, Board::D0, &codec);
#else
VWI rf(0xC05A, 0x02, 4000, Board::D7, Board::D8, &codec);
#endif

// Connect button between ground and pin TinyX4 EXT0/D10, TinyX5
// EXT0/D2, Mega EXT2/D29 and others to Arduino EXT1 which is
// Standard/D3 and Mighty/D11.
class Button : public ExternalInterrupt {
public:
  Button() : 
#if defined(__ARDUINO_MEGA__)
    ExternalInterrupt(Board::EXT2, ExternalInterrupt::ON_LOW_LEVEL_MODE, true)
#elif defined(__ARDUINO_TINY__)
    ExternalInterrupt(Board::EXT0, ExternalInterrupt::ON_LOW_LEVEL_MODE, true)
#else
    ExternalInterrupt(Board::EXT1, ExternalInterrupt::ON_LOW_LEVEL_MODE, true)
#endif
  {}

  virtual void on_interrupt(uint16_t arg = 0) 
