/* ---------------------------------------------------------------------------
 * AVR Blink Demo Application
 * www.mlab.cz miho 2008
 * ---------------------------------------------------------------------------
 * Demo program for AVR processors 
 * Simple blinking application for ATtiny13/ATmega8 and similar
 * ---------------------------------------------------------------------------
 * 00.00 2008/04/18 First Version
 * ---------------------------------------------------------------------------
 */


// Configuration
// -------------


// Define LED port here
// Use port available on all devices with no conflict with ISP port
#define LED			B
#define LED_BIT		3


// Define CPU clock frequency here
// Do not forget to set Clock Oscillator in Low Fuse
// Select just one
//#define F_CPU 1000000UL		// Frequency in Hz
#define F_CPU	F_CPU_DEFAULT	// Default internal RC clock frequency
//#define F_CPU	F_CPU_MAX		// Maximum internal RC clock frequency


// Define blink period
#define PERIOD		5000		// in ms
#define DUTY		20			// in %


// End of Configuration
// --------------------


// Helpers
#define GLUE(a,b)			a##b
#define PORT(a)			    GLUE(PORT,a)
#define PIN(a)				GLUE(PIN,a)
#define DDR(a)				GLUE(DDR,a)


// Port definitions
#define LED_PORT			PORT(LED)
#define LED_DDR				DDR(LED)


// Processor definitions
#include <avr/io.h>


// Define clock values for selected processors

// ATtiny13
#if _AVR_IOTN13_H_
#define F_CPU_DEFAULT	1200000UL	// Default clock 9.6MHz/8
#define F_CPU_MAX		9600000UL	// Maximal internal clock
#endif

// ATmega8/16/32/64
#if _AVR_IOM8_H_ | _AVR_IOM16_H_ | _AVR_IOM32_H_ | _AVR_IOM64_H_ \
	| _AVR_IOM88_H_ 
#define F_CPU_DEFAULT	1000000UL	// Default clock 1MHz
#define F_CPU_MAX		8000000UL	// Maximal internal clock
#endif


// Use delay library
#include <util/delay.h>


// Define ON and OFF times on PERIOD and DUTY
#define TIME_ON		(1L*PERIOD*DUTY/100)
#define TIME_OFF	(1L*PERIOD*(100-DUTY)/100)


// Main program
int main()
{

	LED_DDR |=1<<LED_BIT;			// Set LED port as output

	for(;;)							// Never ending story
	{
		LED_PORT |= 1<<LED_BIT;		// Set LED port to 1
		_delay_ms(TIME_ON);			// Wait
		LED_PORT &= ~(1<<LED_BIT);	// Clear LED port to 0
		_delay_ms(TIME_OFF);		// Wait
	}
	
	return 0;
}