animate-basic.c

#include <avr/io.h>
#include "heart.h"

// note that one second = F_CPU/1024 (currently 1000000/1024)
// also note that the maximum duration one frame = (2^16 - 1) * 1000000/1024
// or about 1min

typedef struct {uint8_t leds[27]; uint16_t dur;} anim_frame;
typedef struct {uint16_t num_frames; anim_frame frames[];} anim;

static const anim ANIMATION = {2, {
  {{
         255, 255,      255, 255,
    255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255,
         255, 255, 255, 255, 255, 
              255, 255, 255,
                   255
    }, 976},
  {{
           0,   0,        0,   0,
      0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,
           0,   0,   0,   0,   0, 
                0,   0,   0,
                     0
    }, 976}
}};

int main() {
  uint8_t mode_pushed = 0;

  DDRA = ALL_INPUT;
  PORTA = ALL_GND_PULL_OFF;
  DDRB = ALL_INPUT;
  PORTB = ALL_POS_PULL_ON;

  // set prescaler to 1024
  TCCR1B = _BV(CS12) | _BV(CS10);
  
  while (1) {
    for (uint16_t f = 0; f < ANIMATION.num_frames; f++) {
      for (TCNT1 = 0; TCNT1 < ANIMATION.frames[f].dur; /*nothing*/) {
        for (uint8_t i = 0; i < 27; i++) {
          uint8_t tmp_port = ALL_GND_PULL_OFF, tmp_ddr = ALL_INPUT;
          if (ANIMATION.frames[f].leds[i]) {
            turn_led_on(&tmp_ddr, &tmp_port, i);
          }
          DDRA = tmp_ddr;
          PORTA = tmp_port;
        }
        DDRA = ALL_INPUT;
        PORTA = ALL_POS_PULL_ON;
        DDRB = ALL_INPUT;
        PORTB = ALL_POS_PULL_ON;

        if (debounce_passed()) {
          //return 0; // works!
          if (mode_pushed && bit_is_clear(MODE_PIN, MODE_BIT)) {
            // just halt for now
            return 0; // not happening :(
            mode_pushed = 0;
          }
        }

        if (bit_is_clear(MODE_PIN, MODE_BIT)) {
          mode_pushed = 1;
          start_debounce();
        }
      }
    }
  }
  DDRA = ALL_INPUT;
  PORTA = ALL_GND_PULL_OFF;
  return 0;
}

heart.h

#include <inttypes.h>

#define LED_DEF(pi_pos, pi_gnd) \
    { \
      pi_pos, pi_gnd \
    }
#define LED_PAIR(pi_pos, pi_gnd) \
    LED_DEF(pi_pos, pi_gnd), \
    LED_DEF(pi_gnd, pi_pos)

typedef struct {uint8_t pos, gnd;} led_pair_t;

static const led_pair_t
  LED_PINS[] = {
    LED_PAIR(5, 4),
    LED_PAIR(5, 3),
    LED_PAIR(5, 2),
    LED_PAIR(5, 1),
    LED_PAIR(5, 0),
    LED_PAIR(4, 3),
    LED_PAIR(4, 2),
    LED_PAIR(4, 1),
    LED_PAIR(4, 0),
    LED_PAIR(3, 2),
    LED_PAIR(3, 1),
    LED_PAIR(3, 0),
    LED_PAIR(2, 1),
    LED_DEF(2, 0),
  };
static const uint8_t NUM_LEDS = 27;

#define POWER_DDR DDRB
#define POWER_PORT PORTB
#define POWER_PIN PINB
static const uint8_t POWER_BIT = 2;

#define MODE_DDR DDRA
#define MODE_PORT PORTA
#define MODE_PIN PINA
static const uint8_t MODE_BIT = 6;

#define DEBOUNCE_COUNTER TCNT0
#define DEBOUNCE_CONTROL TCCR0B

static const uint8_t DEBOUNCE_DELAY = 20;

static inline void start_debounce() {
  DEBOUNCE_COUNTER = 0;
  DEBOUNCE_CONTROL = _BV(CS02) | _BV(CS00);
}

static inline uint8_t debounce_passed() {
  if (DEBOUNCE_COUNTER <= DEBOUNCE_DELAY) return 0;

  DEBOUNCE_CONTROL = 0;
  DEBOUNCE_COUNTER = 0;

  return 1;
}

static const uint8_t ALL_INPUT = 0, ALL_OUTPUT = ~0,
  ALL_POS_PULL_ON = ~0, ALL_GND_PULL_OFF = 0;

static inline void set_output(uint8_t *ddr, uint8_t pin_no) {
  *ddr |= _BV(pin_no);
}

static inline void set_input(uint8_t *ddr, uint8_t pin_no) {
  *ddr &= ~_BV(pin_no);
}

static inline void set_pos(uint8_t *port, uint8_t pin_no) {
  set_output(port, pin_no);
}

static inline void set_gnd(uint8_t *port, uint8_t pin_no) {
  set_input(port, pin_no);
}

static inline void set_pull_on(uint8_t *port, uint8_t pin_no) {
  set_output(port, pin_no);
}

static inline void set_pull_off(uint8_t *port, uint8_t pin_no) {
  set_input(port, pin_no);
}

static inline void turn_led_on(uint8_t *ddr, uint8_t *port, uint8_t num) {
  set_output(ddr, LED_PINS[num].pos);
  set_output(ddr, LED_PINS[num].gnd);
  set_pos(port, LED_PINS[num].pos);
  set_gnd(port, LED_PINS[num].gnd);
}