/* Compile: /bin/bash && avr-gcc -Wall -Wextra -mmcu=attiny13a -Os ./main.c -o ./main.o && avr-objcopy -j .text -j .data -O ihex ./main.o ./main.hex 
 * Write to chip: avrdude -p t13 -c usbasp -U f:w:main.hex
 * Update Fuses: avrdude -p t13 -c usbasp -U lfuse:w:0x79:m -U hfuse:w:0xFF:m
 */



#define F_CPU 1000000UL // 1Mhz Core Clock
#define __AVR_ATtiny13A__ // Chip Part


#define HEAT_KEY PINB3 // 'Heat-ON' Button
#define POWER_SELECT_KEY PINB4 // Power selector (cycle)
#define HEAT_ON TCCR0B |= (1<<CS01); // Set-On clock for T/C0
#define HEAT_OFF TCCR0B &= ~(1<<CS01); // Drop clock for T/C0
#define SSPI_CS_PIN PINB2 // Software SPI clock pin
#define SSPI_MOSI_PIN PINB0 // Software SPI MOSI pin
#define POWER_ADDR 0 // Address of cell for saving selected value of power

#include <avr/io.h>
#include <util/delay.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <avr/eeprom.h>

uint8_t vChar = 0; // 'Vram'
uint8_t power = 0; // Run-time selected power (this var reloaded automatically after RST signal)
const uint8_t tableDefs [10] PROGMEM = { 0x03, 0x9F, 0x25, 0x0D, 0x99, 0x49, 0x41, 0x1F, 0x01, 0x19 }; // Table of characters (For COMMON_ANODE display (for COMMON_____CATHODE_____ - please invert this chars with INV (add ~))

/* LFUSE: 0b01111001 <- 0x79
 * HFUSE: 0xFF
 */

/*
 * 0 = A + B + C + D + E + F         (0x3F)
 * 1 = B + C                         (0x03)
 * 2 = A + B + E + G + D             (0x5B)
 * 3 = A + B + C + G + D             (0x4F)
 * 4 = B + C + F + G                 (0x66)
 * 5 = A + C + D + F + G             (0x79)
 * 6 = A + C + D + E + F + G         (0x7D)
 * 7 = A + B + C                     (0x07)
 * 8 = A + B + C + D + E + F + G     (0x7F)
 * 9 = A + B + C + F + G             (0x67)
 *
 * 
 * A  = 1000 0000 (0x80)
 * B  = 0100 0000 (0x40)
 * C  = 0010 0000 (0x20)
 * D  = 0001 0000 (0x10)
 * E  = 0000 1000 (0x08)
 * F  = 0000 0100 (0x04)
 * G  = 0000 0010 (0x02)
 * DP = 0000 0001 (0x01)
 */

void updateCharOnDisplay (void)
{
	uint8_t	temp = 0;
	temp = pgm_read_byte(&(tableDefs[vChar])); // Load bitmap of char
	
	/* Software SPI WRITE implementation */
	for (uint8_t z = 0; z<8; z++)
	{
		if (temp & 0x01)
		{
			PORTB |= (1<<SSPI_MOSI_PIN);
		}
		else
		{
			PORTB &= ~(1<<SSPI_MOSI_PIN);
		}
	
		__asm__ volatile ("nop");
		__asm__ volatile ("nop");
		__asm__ volatile ("nop");
		__asm__ volatile ("nop");
	
		PORTB &= ~(1<<SSPI_CS_PIN);
	
		__asm__ volatile ("nop");
		__asm__ volatile ("nop");
		__asm__ volatile ("nop");
		__asm__ volatile ("nop");
	
		PORTB |= (1<<SSPI_CS_PIN);
	
		temp = temp>>1;
	}
}

void initPCINT (void)
{
	PCMSK |= (1<<PCINT4)|(1<<PCINT3); // PCINT3, PCINT4 Enabled
}

void updatePower (void)
{
	switch(vChar)
	{
		case 0: power = 25; break; // 10%
		case 1: power = 51; break; // 20%
		case 2: power = 76; break; // 30%
		case 3: power = 102; break; // 40%
		case 4: power = 127; break; // 50%
		case 5: power = 153; break; // 60%
		case 6: power = 178; break; // 70%
		case 7: power = 204; break; // 80%
		case 8: power = 229; break; // 90%
		case 9: power = 255; break; // 100%
		default: break;
		
	}
	
	OCR0B = power;
}

void initT0_PWM (void)
{
	TCCR0A |= (1<<COM0B1)|(1<<WGM01)|(1<<WGM00); // Fast pwm mode(3) (TOP:0xFF), non-inverting mode
	//TCCR0B |= (1<<CS01); // Prescaller = 8 (F_PWM = ~448 Hz)
}

void initGPIO0 (void)
{
	DDRB = 0x00;
	PORTB = 0x00;
	
	DDRB |= (1<<PINB2)|(1<<PINB0)|(1<<PINB1);
	PORTB |= (1<<PINB2);
	
}

int main (void)
{
	cli();
	
	// I/O clock devided by 4 (4.8 Mhz io / 4 = ~1.2 Mhz )
	CLKPR |= (1<<CLKPCE);
	CLKPR |= (1<<CLKPS1);
	CLKPR &= ~(1<<CLKPCE);
	
	
	// Restore the Last selected Power value
	vChar = eeprom_read_byte(POWER_ADDR);
	
	
	initGPIO0();
	initT0_PWM();
	initPCINT();
	
	updateCharOnDisplay();
	updatePower();
	
	
	MCUCR |= (1<<PUD); // All Pull-Up disabled NOW
	
	while(1)
	{
			
		if (GIFR & (1<<PCIF))
		{
			if (PINB & (1<<HEAT_KEY))
			{
				_delay_ms(20);
				if (PINB & (1<<HEAT_KEY))
				{
					
					DDRB |= (1<<PINB1);
					__asm__ volatile ("nop");
					__asm__ volatile ("nop");
					__asm__ volatile ("nop");
					__asm__ volatile ("nop");
					
					HEAT_ON;
					
					GIFR |= (1<<PCIF);
				}
				
			}
			else
			{
				_delay_ms(20);
				if (!( PINB & (1<<HEAT_KEY)))
				{
				
					HEAT_OFF;	
					// -- Just a FEATURE-- //
					
						DDRB &= ~(1<<PINB1);
						PORTB &= ~(1<<PINB1);
										
					GIFR |= (1<<PCIF);
				}

			
			}
			if (PINB & (1<<POWER_SELECT_KEY))
			{
				_delay_ms(20);
				if (PINB & (1<<POWER_SELECT_KEY))
				{
					vChar = (vChar+1)%10;
					
					eeprom_write_byte(POWER_ADDR, vChar);
					
					updateCharOnDisplay();
					updatePower();
					GIFR |= (1<<PCIF);
				}
			}
			else
			{
			}
		}	
	
	}
	
}