/*
  Charliplexing.h - Using timer2 with 1ms resolution
  
  Alex Wenger <a.wenger@gmx.de> http://arduinobuch.wordpress.com/
  
  Timer init code from MsTimer2 - Javier Valencia <javiervalencia80@gmail.com>
  
  History:
  	30/Dez/09 - V0.0 wrote the first version at 26C3/Berlin

  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.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "WProgram.h"
#include <inttypes.h>
#include <avr/interrupt.h>
#include "Charliplexing.h"


volatile unsigned int LedSign::tcnt2;

// Table for the LED multiplexing cycles, containing 12 cycles made out of two bytes
uint8_t leds[24];


// Table for LED Position in leds[] ram table
const uint8_t ledMap[252] = { 
    13, 5,13, 6,13, 7,13, 8,13, 9,13,10,13,11,13,12,13, 4, 4,13,13, 3, 3,13,13, 2, 2,13,
    12, 5,12, 6,12, 7,12, 8,12, 9,12,10,12,11,12,13,12, 4, 4,12,12, 3, 3,12,12, 2, 2,12,
    11, 5,11, 6,11, 7,11, 8,11, 9,11,10,11,12,11,13,11, 4, 4,11,11, 3, 3,11,11, 2, 2,11,
    10, 5,10, 6,10, 7,10, 8,10, 9,10,11,10,12,10,13,10, 4, 4,10,10, 3, 3,10,10, 2, 2,10,
     9, 5, 9, 6, 9, 7, 9, 8, 9,10, 9,11, 9,12, 9,13, 9, 4, 4, 9, 9, 3, 3, 9, 9, 2, 2, 9,
     8, 5, 8, 6, 8, 7, 8, 9, 8,10, 8,11, 8,12, 8,13, 8, 4, 4, 8, 8, 3, 3, 8, 8, 2, 2, 8,
     7, 5, 7, 6, 7, 8, 7, 9, 7,10, 7,11, 7,12, 7,13, 7, 4, 4, 7, 7, 3, 3, 7, 7, 2, 2, 7,
     6, 5, 6, 7, 6, 8, 6, 9, 6,10, 6,11, 6,12, 6,13, 6, 4, 4, 6, 6, 3, 3, 6, 6, 2, 2, 6,
     5, 6, 5, 7, 5, 8, 5, 9, 5,10, 5,11, 5,12, 5,13, 5, 4, 4, 5, 5, 3, 3, 5, 5, 2, 2, 5,
    };


// Constructor / init interrupt 
void LedSign::Init(void)
{
	float prescaler = 0.0;
	
#if defined (__AVR_ATmega168__) || defined (__AVR_ATmega48__) || defined (__AVR_ATmega88__) || defined (__AVR_ATmega328P__) || (__AVR_ATmega1280__)
	TIMSK2 &= ~(1<<TOIE2);
	TCCR2A &= ~((1<<WGM21) | (1<<WGM20));
	TCCR2B &= ~(1<<WGM22);
	ASSR &= ~(1<<AS2);
	TIMSK2 &= ~(1<<OCIE2A);
	
	if ((F_CPU >= 1000000UL) && (F_CPU <= 16000000UL)) {	// prescaler set to 64
		TCCR2B |= (1<<CS22);
		TCCR2B &= ~((1<<CS21) | (1<<CS20));
		prescaler = 64.0;
	} else if (F_CPU < 1000000UL) {	// prescaler set to 8
		TCCR2B |= (1<<CS21);
		TCCR2B &= ~((1<<CS22) | (1<<CS20));
		prescaler = 8.0;
	} else { // F_CPU > 16Mhz, prescaler set to 128
		TCCR2B |= ((1<<CS22) | (1<<CS20));
		TCCR2B &= ~(1<<CS21);
		prescaler = 128.0;
	}
#elif defined (__AVR_ATmega8__)
	TIMSK &= ~(1<<TOIE2);
	TCCR2 &= ~((1<<WGM21) | (1<<WGM20));
	TIMSK &= ~(1<<OCIE2);
	ASSR &= ~(1<<AS2);
	
	if ((F_CPU >= 1000000UL) && (F_CPU <= 16000000UL)) {	// prescaler set to 64
		TCCR2 |= (1<<CS22);
		TCCR2 &= ~((1<<CS21) | (1<<CS20));
		prescaler = 64.0;
	} else if (F_CPU < 1000000UL) {	// prescaler set to 8
		TCCR2 |= (1<<CS21);
		TCCR2 &= ~((1<<CS22) | (1<<CS20));
		prescaler = 8.0;
	} else { // F_CPU > 16Mhz, prescaler set to 128
		TCCR2 |= ((1<<CS22) && (1<<CS20));
		TCCR2 &= ~(1<<CS21);
		prescaler = 128.0;
	}
#elif defined (__AVR_ATmega128__)
	TIMSK &= ~(1<<TOIE2);
	TCCR2 &= ~((1<<WGM21) | (1<<WGM20));
	TIMSK &= ~(1<<OCIE2);
	
	if ((F_CPU >= 1000000UL) && (F_CPU <= 16000000UL)) {	// prescaler set to 64
		TCCR2 |= ((1<<CS21) | (1<<CS20));
		TCCR2 &= ~(1<<CS22);
		prescaler = 64.0;
	} else if (F_CPU < 1000000UL) {	// prescaler set to 8
		TCCR2 |= (1<<CS21);
		TCCR2 &= ~((1<<CS22) | (1<<CS20));
		prescaler = 8.0;
	} else { // F_CPU > 16Mhz, prescaler set to 256
		TCCR2 |= (1<<CS22);
		TCCR2 &= ~((1<<CS21) | (1<<CS20));
		prescaler = 256.0;
	}
#endif
	
	tcnt2 = 256 - (int)((float)F_CPU * 0.001 / prescaler);
	
#if defined (__AVR_ATmega168__) || defined (__AVR_ATmega48__) || defined (__AVR_ATmega88__) || defined (__AVR_ATmega328P__) || (__AVR_ATmega1280__)
	TCNT2 = tcnt2;
	TIMSK2 |= (1<<TOIE2);
#elif defined (__AVR_ATmega128__)
	TCNT2 = tcnt2;
	TIMSK |= (1<<TOIE2);
#elif defined (__AVR_ATmega8__)
	TCNT2 = tcnt2;
	TIMSK |= (1<<TOIE2);
#endif	
}

// Function to switch on and off the leds. All the position
// calculations are done here, so we donīt need to do in the
// interrupt code
void LedSign::Set(uint8_t x, uint8_t y, uint8_t c)
{
  uint8_t pin_low  = ledMap[x*2+y*28+1];
  uint8_t pin_high = ledMap[x*2+y*28+0];
  // pin_low ist directly the adress in the led array (minus 2 because the 
  // first two bytes are used for RS232 communication, but
  // as it is a two byte array we need to check pin_high also.
  // If pin_high is bigger than 8 adress has to be increased by one
  if (c == 1) {
	leds[(pin_low-2)*2 + (pin_high / 8)] |=  _BV(pin_high & 0x07);   // ON
  } 
  else {
	leds[(pin_low-2)*2 + (pin_high / 8)] &= ~_BV(pin_high & 0x07);   // OFF
  }
}


ISR(TIMER2_OVF_vect) {
#if defined (__AVR_ATmega168__) || defined (__AVR_ATmega48__) || defined (__AVR_ATmega88__) || defined (__AVR_ATmega328P__) || (__AVR_ATmega1280__)
	TCNT2 = LedSign::tcnt2;
#elif defined (__AVR_ATmega128__)
	TCNT2 = LedSign::tcnt2;
#elif defined (__AVR_ATmega8__)
	TCNT2 = LedSign::tcnt2;
#endif

  // 12 Cycles of Matrix
  static uint8_t i;
  
  i++;
  if (i > 12) i = 0;
  
  if (i < 6) {
    DDRD  = _BV(i+2) | leds[i*2];
	PORTD =            leds[i*2];

	DDRB  =            leds[i*2+1];
	PORTB =            leds[i*2+1];
  } else {
	DDRD =             leds[i*2];
	PORTD =            leds[i*2];

	DDRB  = _BV(i-6) | leds[i*2+1];
	PORTB =            leds[i*2+1];      
  } 
  /*
  PORTB = 0xff;
  PORTD = i;
  DDRB  = 0xff;
  DDRD  = 0xff;
  */
}