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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"
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) {
write_time(minutes, seconds, current_digit);
// Cycle through the 4 digits
current_digit = (current_digit + 1) % 4;
}
// TODO: Wtf. Fix the names
#define DSEGMENT_1 6
#define DSEGMENT_MASK_1 ((1 << 6) | (1 << 7))
#define DSEGMENT_2 5
#define DSEGMENT_MASK_2 ((1 << 5) | (1 << 10))
#define ALL_DUAL_PURPOSE_PINS (DSEGMENT_MASK_1 | DSEGMENT_MASK_2)
uint8_t dual_purpose_pins[] = {6, 7, 5, 10};
uint8_t dual_purpose_antipins[] = {7, 6, 10, 5};
void write_time(uint16_t hour, uint16_t minute, uint8_t digit_index) {
// reset pins
uint32_t ddr = ~ALL_DUAL_PURPOSE_PINS;
uint32_t port = 0;
uint8_t digit = get_digit(hour, minute, digit_index);
uint32_t segments = get_digit_mask(digit);
uint8_t pin = dual_purpose_pins[digit_index];
uint8_t antipin = dual_purpose_antipins[digit_index];
uint8_t segment_pin = digit_index / 2 == 0 ? DSEGMENT_1 : DSEGMENT_2;
uint8_t other_segment_pin = digit_index / 2 == 0 ? DSEGMENT_2 : DSEGMENT_1;
uint8_t other_segment_mask =
digit_index / 2 == 0 ? DSEGMENT_MASK_2 : DSEGMENT_MASK_1;
port = segments;
// Activate dual purpose segment
ddr |= (1 << pin);
port |= (1 << pin);
if (segments & (1 << segment_pin)) {
// If seg inactive, enable other input and enable pull up res
ddr &= ~(1 << antipin);
port |= (1 << antipin);
} else {
// If seg active, enable other output and set to 0
ddr |= (1 << antipin);
port &= ~(1 << antipin);
}
// Activate other dual purpose segment
if ((segments & (1 << other_segment_pin)) == 0) {
ddr |= other_segment_mask;
port &= ~other_segment_mask;
}
// cli();
DDRA = ddr;
DDRB = ddr >> 8;
PORTA = port;
PORTB = port >> 8;
// sei();
}
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