main.c

#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <stdbool.h>

static void init(void);

#define A_BUTTON		128
#define B_BUTTON		64
#define RIGHT_BUTTON		32
#define DOWN_BUTTON		16
#define UP_BUTTON		8
#define LEFT_BUTTON		4

#define NOTE_A5		1136
#define NOTE_GS5	1203
#define NOTE_G5		1275
#define NOTE_F5		1431
#define NOTE_E5		1516
#define NOTE_D5		1702
#define NOTE_C5		1911
#define NOTE_B4		2024
#define NOTE_A4		2272
#define NOTE_GS4	2407

typedef struct
{
	int8_t second;
	int8_t minute;
	int8_t hour;
} time;

time t;
bool clockMode;
uint16_t counter;
int8_t d2, d3, d4, position, player, obstacles;
uint8_t SEG_1B, SEG_1C;
uint8_t SEG_2A, SEG_2B, SEG_2C, SEG_2D, SEG_2E, SEG_2F, SEG_2G;
uint8_t SEG_3A, SEG_3B, SEG_3C, SEG_3D, SEG_3E, SEG_3F, SEG_3G;
uint8_t noteIndex, currentButtonState, previousButtonState;
const uint16_t notes[192] PROGMEM = {NOTE_E5, NOTE_E5, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_C5, NOTE_E5, NOTE_E5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_C5, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_D5, NOTE_F5, NOTE_A5, NOTE_A5, NOTE_G5, NOTE_F5, NOTE_E5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_E5, NOTE_E5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_C5, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_B4, NOTE_C5, NOTE_E5, NOTE_E5, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_C5, NOTE_E5, NOTE_E5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_C5, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_D5, NOTE_F5, NOTE_A5, NOTE_A5, NOTE_G5, NOTE_F5, NOTE_E5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_E5, NOTE_E5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_C5, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_B4, NOTE_C5, NOTE_E5, NOTE_E5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_D5, NOTE_D5, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_A4, NOTE_GS4, NOTE_GS4, NOTE_GS4, NOTE_GS4, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_E5, NOTE_E5, NOTE_E5, NOTE_E5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_D5, NOTE_D5, NOTE_D5, NOTE_D5, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_B4, NOTE_C5, NOTE_C5, NOTE_E5, NOTE_E5, NOTE_A5, NOTE_A5, NOTE_A5, NOTE_A5, NOTE_GS5, NOTE_GS5, NOTE_GS5, NOTE_GS5, NOTE_GS5, NOTE_GS5, NOTE_A4, NOTE_C5};

uint8_t buttonsState(void)
{
	return ((~PINE) & 0b11111100);
}

void pollButtons(void)
{
	previousButtonState = currentButtonState;
	currentButtonState = buttonsState();
}

bool pressed(uint8_t buttons)
{
	return (buttonsState() & buttons) == buttons;
}

bool justPressed(uint8_t button)
{
	return (!(previousButtonState & button) && (currentButtonState & button));
}

bool justReleased(uint8_t button)
{
	return ((previousButtonState & button) && !(currentButtonState & button));
}

int main(void)
{
	ASSR = 0b00001000; // Asynchronous Timer/Counter2
	ADCSRA = 0b00000000; // Disable ADC
	PRR = 0b00000011; // Power Reduction Register (Shutdown USART/ADC)
	LCDFRR = 0b01000000; // Prescaler clkLCD/512
	LCDCCR = 0b00010000; // LCD Maximum Drive Time
	LCDCRB = 0b10000111; // LCD Clock Select, LCD Mux Select, LCD Port Mask
	LCDCRA = 0b10000110; // LCD Enable, LCD Buffer Disable, LCD Contrast Control Disable

	DDRA = 0b11110001; // COM0, SEG0-SEG3
	DDRB = 0b01000110; // SPI, Buzzer
	DDRC = 0b11111111; // SEG12-SEG5
	DDRD = 0b11111111; // SEG22-SEG15
	DDRE = 0b00000000; // Button Inputs
	DDRF = 0b10001101; // XOR 1A,3A,4A,2A
	DDRG = 0b00011111; // SEG14,SEG13,SEG4,SEG24,SEG23

	// enable pull-ups on inputs and unused pins
	PORTA = 0b00001110;
	PORTB = 0b10110001;
	PORTE = 0b11111111;
	PORTF = 0b01110010;

	// set up Timer 1
	TCCR1A = 0; // set normal mode (which disconnects the pin)
	TCCR1B = 0b00001001; // CTC mode, No prescaling

	t.hour = 12;
	clockMode = true;

	/* Initialize registers and configure RTC. */
	init();

	while (1)
	{
		pollButtons();

		if (justReleased(B_BUTTON))
		{
			if (clockMode) // leaving clock mode
			{
				clockMode = false;
				SEG_1C = 0;
				SEG_1B = 0;
				counter = 0;
				position = 4;
				obstacles = 0;
				d2 = -1;
				d3 = -1;
				d4 = -1;
			}
			else if (!clockMode) // leaving game mode
			{
				clockMode = true;
				PORTF = 0b01110010;
				TCCR1A = 0; // set normal mode (which disconnects the pin)
			}
		}

		if (clockMode)
		{
			if (justReleased(UP_BUTTON) || justReleased(DOWN_BUTTON))
			{
				t.second = 0;
				TIMSK2 = 1; // Enable Overflow Interrupt
				TCCR1A = 0; // set normal mode (which disconnects the pin)
			}

			if (justPressed(UP_BUTTON) || justPressed(DOWN_BUTTON))
			{
				TIMSK2 = 0; // Disable Overflow Interrupt
				PORTF = 0b01110010; // Disable Colon
				OCR1A = pgm_read_word(&notes[noteIndex]);
				TCCR1A = 0b00010000; // set toggle on compare mode (which connects the pin)
				counter = 0;
			}

			if (pressed(UP_BUTTON) && ++counter == 200)
			{
				counter = 0;

				if(++noteIndex == 192) noteIndex = 0;

				OCR1A = pgm_read_word(&notes[noteIndex]);

				if (++t.minute == 60)
				{
					t.minute = 0;
					if (++t.hour == 13)
					{
						t.hour = 1;
					}
				}
			}
			else if (pressed(DOWN_BUTTON) && ++counter == 200)
			{
				counter = 0;

				if(++noteIndex == 192) noteIndex = 0;

				OCR1A = pgm_read_word(&notes[noteIndex]);

				if (--t.minute == -1)
				{
					t.minute = 59;
					if (--t.hour == 0)
					{
						t.hour = 12;
					}
				}
			}

			d3 = 0;
			d4 = t.minute;

			while (d4 > 9)
			{
				d4 = d4 - 10;
				d3 = d3 + 1;
			}

			if (t.hour > 9)
			{
				d2 = t.hour - 10;
				SEG_1C = 2;
				SEG_1B = 128;
			}
			else
			{
				d2 = t.hour;
				SEG_1C = 0;
				SEG_1B = 0;
			}
		}
		else // game mode
		{
			if (pressed(UP_BUTTON))
			{
				PORTF = 0b00001000; // player top (SEG_1A)
				player = 10;
			}
			else if (pressed(DOWN_BUTTON))
			{
				PORTF = 0b10000000; // player bottom (SEG_1D)
				player = 11;
			}
			else
			{
				PORTF = 0b00000001; // player middle (SEG_1G)
			}

			if (counter == 1500)
			{
				OCR1A = 2272; // 440Hz
				TCCR1A = 0b00010000; // set toggle on compare mode (which connects the pin)
			}

			if (++counter == 2000)
			{
				switch(position)
				{
					case 1:
						if (player == d2) // GAME OVER!
						{
							for (uint16_t z = 0; z < 65535; z++)
							{
								switch(z)
								{
									case 0: // SEG A
										OCR1A = 1136; // 880Hz, see https://pages.mtu.edu/~suits/notefreqs.html and https://eleccelerator.com/avr-timer-calculator/
										LCDDR2 = 0b00010001;
										LCDDR1 = 0b00010000;
										LCDDR0 = 0;
										PORTF = 0b00001000;
										break;
									case 4096:
										OCR1A = 1203; // 830.61Hz
										break;
									case 8192: // SEG F
										OCR1A = 1275; // 783.99Hz
										LCDDR3 = 0b00000001;
										LCDDR2 = 0b00100010;
										LCDDR1 = 0b00100000;
										PORTF = 0;
										break;
									case 12288:
										OCR1A = 1351; // 739.99Hz
										break;
									case 16384: // SEG G
										OCR1A = 1431; // 698.46Hz
										LCDDR3 = 0;
										LCDDR2 = 0b01000100;
										LCDDR1 = 0b01000000;
										PORTF = 0b00000001;
										break;
									case 20480:
										OCR1A = 1516; // 659.25Hz
										break;
									case 24576: // SEG C
										OCR1A = 1607; // 622.25Hz
										LCDDR2 = 0;
										LCDDR1 = 0b00000100;
										LCDDR0 = 0b10010010;
										PORTF = 0;
										break;
									case 28672:
										OCR1A = 1702; // 587.33Hz
										break;
									case 32768: // SEG D
										OCR1A = 1803; // 554.37Hz
										LCDDR1 = 0b00000010;
										LCDDR0 = 0b01001000;
										PORTF = 0b10000000;
										break;
									case 36864:
										OCR1A = 1911; // 523.25Hz
										break;
									case 40960: // SEG E
										OCR1A = 2024; // 493.88Hz
										LCDDR1 = 0b00000001;
										LCDDR0 = 0b00100101;
										PORTF = 0;
										break;
									case 45056:
										OCR1A = 2145; // 466.16Hz
										break;
									case 49152: // SEG G
										OCR1A = 2272; // 440Hz
										LCDDR2 = 0b01000100;
										LCDDR1 = 0b01000000;
										LCDDR0 = 0;
										PORTF = 0b00000001;
										break;
									case 53248:
										OCR1A = 2407; // 415.3Hz
										break;
									case 57344: // SEG B
										OCR1A = 2551; // 392Hz
										LCDDR2 = 0b10001000;
										LCDDR1 = 0b10001000;
										PORTF = 0b01110010;
										break;
								}
							}
							clockMode = true;
						}
						else
						{
							for (uint16_t z = 0; z < 20000; z++)
							{
								switch(z)
								{
									case 0:
										OCR1A = 1136; // 880Hz
										break;
									case 10000:
										OCR1A = 568; // 1760Hz
										break;
								}
							}
						}
						d2 = -1;
						position = 4;
						break;
					case 2:
						d2 = d3;
						d3 = -1;
						player = d2;
						position--;
						break;
					case 3:
						d3 = d4;
						d4 = -1;
						position--;
						break;
					case 4:
						if (TCNT2 & 1) d4 = 10;
						else d4 = 11;
						position--;
						break;
				}

				TCCR1A = 0; // set normal mode (which disconnects the pin)

				counter = ++obstacles * 10;

				if (counter > 1450) counter = 1450;
			}
		}

		// DIGIT2
		if (d2 == 0 || d2 == 2 || d2 == 3 || d2 == 5 || d2 == 6 || d2 == 7 || d2 == 8 || d2 == 9 || d2 == 10) SEG_2A = 16;
		else SEG_2A = 0;
		if (d2 == 0 || d2 == 1 || d2 == 2 || d2 == 3 || d2 == 4 || d2 == 7 || d2 == 8 || d2 == 9 || d2 == 10) SEG_2B = 8;
		else SEG_2B = 0;
		if (d2 == 0 || d2 == 1 || d2 == 3 || d2 == 4 || d2 == 5 || d2 == 6 || d2 == 7 || d2 == 8 || d2 == 9 || d2 == 11) SEG_2C = 16;
		else SEG_2C = 0;
		if (d2 == 0 || d2 == 2 || d2 == 3 || d2 == 5 || d2 == 6 || d2 == 8 || d2 == 9 || d2 == 11) SEG_2D = 8;
		else SEG_2D = 0;
		if (d2 == 0 || d2 == 2 || d2 == 6 || d2 == 8 || d2 == 11) SEG_2E = 4;
		else SEG_2E = 0;
		if (d2 == 0 || d2 == 4 || d2 == 5 || d2 == 6 || d2 == 7 || d2 == 8 || d2 == 9 || d2 == 10) SEG_2F = 32;
		else SEG_2F = 0;
		if (d2 == 2 || d2 == 3 || d2 == 4 || d2 == 5 || d2 == 6 || d2 == 8 || d2 == 9 || d2 == 10 || d2 == 11) SEG_2G = 64;
		else SEG_2G = 0;

		// DIGIT3
		if (d3 == 0 || d3 == 2 || d3 == 3 || d3 == 5 || d3 == 10) SEG_3A = 1;
		else SEG_3A = 0;
		if (d3 == 0 || d3 == 1 || d3 == 2 || d3 == 3 || d3 == 4 || d3 == 10) SEG_3B = 128;
		else SEG_3B = 0;
		if (d3 == 0 || d3 == 1 || d3 == 3 || d3 == 4 || d3 == 5 || d3 == 11) SEG_3C = 128;
		else SEG_3C = 0;
		if (d3 == 0 || d3 == 2 || d3 == 3 || d3 == 5 || d3 == 11) SEG_3D = 64;
		else SEG_3D = 0;
		if (d3 == 0 || d3 == 2 || d3 == 11) SEG_3E = 32;
		else SEG_3E = 0;
		if (d3 == 0 || d3 == 4 || d3 == 5 || d3 == 10) SEG_3F = 2;
		else SEG_3F = 0;
		if (d3 == 2 || d3 == 3 || d3 == 4 || d3 == 5 || d3 == 10 || d3 == 11) SEG_3G = 4;
		else SEG_3G = 0;

		LCDDR0 = SEG_3C + SEG_3D + SEG_3E + SEG_2C + SEG_2D + SEG_2E + SEG_1C;
		LCDDR2 = SEG_1B + SEG_2G + SEG_2F + SEG_2A + SEG_2B + SEG_3G + SEG_3F + SEG_3A;

		// DIGIT4
		switch(d4)
		{
			case 0:
				LCDDR1 = 0b00111111 + SEG_3B;
				break;
			case 1:
				LCDDR1 = 0b00001100 + SEG_3B;
				break;
			case 2:
				LCDDR1 = 0b01011011 + SEG_3B;
				break;
			case 3:
				LCDDR1 = 0b01011110 + SEG_3B;
				break;
			case 4:
				LCDDR1 = 0b01101100 + SEG_3B;
				break;
			case 5:
				LCDDR1 = 0b01110110 + SEG_3B;
				break;
			case 6:
				LCDDR1 = 0b01110111 + SEG_3B;
				break;
			case 7:
				LCDDR1 = 0b00111100 + SEG_3B;
				break;
			case 8:
				LCDDR1 = 0b01111111 + SEG_3B;
				break;
			case 9:
				LCDDR1 = 0b01111110 + SEG_3B;
				break;
			case 10: // top obstacle
				LCDDR1 = 0b01111000;
				break;
			case 11: // bottom obstacle
				LCDDR1 = 0b01000111;
				break;
			default:
				LCDDR1 = 0b00000000 + SEG_3B;
		}
	}
}

// AVR134: Real Time Clock (RTC) Using the Asynchronous Timer
static void init(void)
{
	/* Wait for external clock crystal to stabilize */
	for (uint16_t j = 0; j < 0xFFFF; j++)
	{
		/* Do a nop instruction to keep the empty
		 * loop from being optimized away */
		asm volatile("nop");
	}

	/* Make sure all TC2 interrupts are disabled */
	TIMSK2 = 0;

	/* Reset timer */
	TCNT2 = 0;

	/* Prescale the timer to be clock source/64 to make */
	/* TC2 overflow precisely twice every second. */
	TCCR2A = (1 << CS22);

	/* Wait until TC2 is updated */
	while (ASSR & ((1 << TCN2UB) | (1 << OCR2UB) | (1 << TCR2UB))) {}

	/* Enable Timer/Counter2 Overflow Interrupt */
	TIMSK2 = 1;

	/* Set the Global Interrupt Enable Bit */
	sei();
}

/* keep track of time */
ISR(TIMER2_OVF_vect)
{
	if (clockMode) PINF = 0b00000100; // toggle colon

	if (++t.second == 120)
	{
		t.second = 0;
		if (++t.minute == 60)
		{
			t.minute = 0;
			if (++t.hour == 13)
			{
				t.hour = 1;
			}
		}
	}
}