Počítadlo na displeji, které přežije vypnutí

arduino/DisplejTlacitko/DisplejTlacitko.ino

#include <LiquidCrystal.h>
#include <EEPROM.h>

// Zapojeni zjistene diagnostikou: RS=12, E=11, D4..D7 = 5,4,3,2
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const byte BUTTON_PIN = 6;  // klidova uroven se zjistuje pri startu (u tohoto zapojeni LOW, stisk = HIGH)

// Casy drzeni tlacitka (ms od stisku)
const unsigned long WARN1_MS = 2000;      // "Nedrz to.. / Resetujes to"
const unsigned long WARN2_MS = 5000;      // "Nebud debil / Smazes to"
const unsigned long COUNTDOWN_MS = 7000;  // odpocet 3, 2, 1 (7-10 s)
const unsigned long BLANK_MS = 10000;     // prazdny displej
const unsigned long RESET_PROMPT_MS = 11000;  // "Pust tlacitko" - reset se provede az po potvrzeni
const unsigned long DOUBLE_PRESS_MS = 600;    // okno pro druhy stisk (zruseni)

// Ukladani s rozlozenim opotrebeni: EEPROM je kruhovy buffer zaznamu.
// Kazdy zapis jde do dalsiho zaznamu, nejnovejsi ma nejvyssi poradi (seq).
struct Record {
  unsigned long seq;
  unsigned long count;
  unsigned long check;  // seq ^ count ^ KEY, odfiltruje stare/nahodne data
};

const unsigned long KEY = 0xA5C3A5C3UL;
const int SLOTS = EEPROM.length() / sizeof(Record);

int slot = 0;
unsigned long seq = 0;
unsigned long count = 0;

bool validRecord(const Record &r) {
  return r.check == (r.seq ^ r.count ^ KEY);
}

void loadCount() {
  bool found = false;
  for (int i = 0; i < SLOTS; i++) {
    Record r;
    EEPROM.get(i * sizeof(Record), r);
    if (validRecord(r) && (!found || r.seq > seq)) {
      found = true;
      seq = r.seq;
      count = r.count;
      slot = i;
    }
  }
  if (!found) {
    count = 0;
    seq = 0;
    slot = SLOTS - 1;  // prvni zapis pujde do slotu 0
  }
}

void saveCount() {
  slot = (slot + 1) % SLOTS;
  seq++;
  Record r = {seq, count, seq ^ count ^ KEY};
  EEPROM.put(slot * sizeof(Record), r);
}

enum Mode { NORMAL, WAIT_RELEASE, CONFIRM };
Mode mode = NORMAL;

bool idleLevel = LOW;     // klidova uroven pinu, zjisti se pri startu
bool lastState = LOW;
unsigned long lastChange = 0;
unsigned long pressStart = 0;
unsigned long lastRelease = 0;
int shownStage = -1;
byte presses = 0;
bool ignoreNextRelease = false;

void show() {
  lcd.clear();
  lcd.print(F("Like a Bosch"));
  lcd.setCursor(0, 1);
  lcd.print(F("Stisku: "));
  lcd.print(count);
}

void twoLines(const __FlashStringHelper *a, const __FlashStringHelper *b) {
  lcd.clear();
  lcd.print(a);
  lcd.setCursor(0, 1);
  lcd.print(b);
}

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  delay(100);
  idleLevel = digitalRead(BUTTON_PIN);  // tlacitko se pri startu nedrzi
  lastState = idleLevel;
  loadCount();
  lcd.begin(16, 2);
  show();
}

// Upozorneni behem drzeni tlacitka, meni se jen pri zmene faze
void showHoldStage(unsigned long held) {
  int stage;
  if (held >= BLANK_MS) stage = 5;
  else if (held >= COUNTDOWN_MS) stage = 10 + (3 - (int)((held - COUNTDOWN_MS) / 1000));  // 13, 12, 11
  else if (held >= WARN2_MS) stage = 2;
  else if (held >= WARN1_MS) stage = 1;
  else return;
  if (stage == shownStage) return;
  shownStage = stage;
  if (stage == 1) {
    twoLines(F("Nedrz to.."), F("Resetujes to"));
  } else if (stage == 2) {
    twoLines(F("Nebud debil"), F("Smazes to"));
  } else if (stage >= 10) {
    twoLines(F("Reset za"), F(""));
    lcd.setCursor(7, 1);
    lcd.print(stage - 10);
  } else {
    lcd.clear();
  }
}

void doReset() {
  count = 0;
  saveCount();
  twoLines(F("Reset"), F("hotovo"));
  delay(1000);
  mode = NORMAL;
  show();
}

void loop() {
  bool state = digitalRead(BUTTON_PIN);
  if (state != lastState && millis() - lastChange > 50) {
    lastChange = millis();
    lastState = state;
    bool pressed = (state != idleLevel);
    if (mode == NORMAL) {
      if (pressed) {
        pressStart = millis();
        shownStage = -1;
        ignoreNextRelease = false;
      } else if (ignoreNextRelease) {
        ignoreNextRelease = false;
      } else {
        count++;  // pusteno pred 11 s = bezny stisk
        saveCount();
        show();
      }
    } else if (mode == WAIT_RELEASE) {
      if (!pressed) {
        mode = CONFIRM;
        presses = 0;
        twoLines(F("Potvrdit: 1x"), F("Zrusit: 2x"));
      }
    } else {  // CONFIRM
      if (pressed) {
        presses++;
        if (presses >= 2) {  // dvakrat = zrusit
          mode = NORMAL;
          ignoreNextRelease = true;  // druhy stisk se jeste drzi
          show();
        }
      } else {
        lastRelease = millis();
      }
    }
  }

  if (mode == NORMAL && lastState != idleLevel && !ignoreNextRelease) {
    unsigned long held = millis() - pressStart;
    if (held >= RESET_PROMPT_MS) {
      mode = WAIT_RELEASE;
      twoLines(F("Pust tlacitko"), F("a potvrd reset"));
    } else {
      showHoldStage(held);
    }
  }

  if (mode == CONFIRM && presses == 1 && lastState == idleLevel &&
      millis() - lastRelease > DOUBLE_PRESS_MS) {
    doReset();  // jednou = potvrdit
  }
}