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#include <avr/interrupt.h>
#include <avr/io.h>
#include <stdint.h>
#include <util/delay.h>
#include "display.h"
#include "rtc.h"
// "_gfedcba"
// Reversed because a-g is mapped to pa0-6. (pa7 is decimal)
// Complemented because display is common anode
const uint32_t digit_masks[] = {
0b01000000, 0b01111001, 0b00100100, 0b00110000, 0b00011001,
0b00010010, 0b00000010, 0b01111000, 0b00000000, 0b00010000,
};
void display_setup() {
// Set prescaler CS01 + CS00 (F_CPU / 64) + CTC
// For 32768Hz -> 32768/64 = 512Hz
TCCR0B = (1 << CS01) | (1 << CS00) | (1 << WGM02);
TCCR0A = (1 << WGM01) | (1 << WGM00);
TCNT0 = 0; // Start counting from 0
OCR0A = 1; // 0-1 = 2 counts before timer interrupt (512/2 = 256Hz)
OCR0B = 0;
TIFR0 = (1 << OCF0A) | (1 << OCF0B) | (1 << TOV0); // Clear interrupt flags
TIMSK0 = (1 << OCIE0A); // Enable timer overflow interrupt
// Draw startup state
DDRA |= 0b11111111;
DDRB |= 0b11111111;
PORTA = (1 << PA7);
PORTB = (1 << PB2);
}
volatile uint8_t current_digit = 0;
// Render current digit
void display_render(void) {
DDRA |= 0b11111111;
DDRB |= 0b11111111;
write_time(minutes, seconds, current_digit);
// Next digit
current_digit = (current_digit + 1) % 4;
}
void write_digit(uint8_t digit) {
if (digit > 9 || digit < 0)
return;
PORTA = digit_masks[digit];
}
void write_time(uint16_t hour, uint16_t minute, uint8_t mask) {
uint8_t minute_digit1 = minute % 10;
uint8_t minute_digit2 = (minute / 10) % 10;
// unsigned short hour_digit1 = hour % 10;
// unsigned short hour_digit2 = (hour / 10) % 10;
// Reset digit control pins
PORTA &= ~(1 << PA7); // minute digit 1
PORTB &= ~(1 << PB2); // minute digit 2
// cli();
if (mask == 0 || mask == 2) {
#ifdef STUBBED
printf(" %d\n", minute_digit1);
fflush(stdout);
#endif
write_digit(minute_digit1);
PORTA |= (1 << PA7);
}
if (mask == 1 || mask == 3) {
#ifdef STUBBED
printf(":: %d", minute_digit2);
fflush(stdout);
#endif
write_digit(minute_digit2);
PORTB |= (1 << PB2);
}
// sei();
}
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