Medication Confirmation Reminder

#include <Wire.h>
#include <RTClib.h>
#include <Adafruit_FRAM_I2C.h>
#include <DFRobot_RGBLCD1602.h>

const uint8_t I2C_SDA_PIN = 4;
const uint8_t I2C_SCL_PIN = 5;
const uint8_t BUZZER_PIN = 6;
const uint8_t CONFIRM_PIN = 7;
const uint8_t SET_PIN = 8;
const uint8_t NEXT_PIN = 9;
const uint8_t DOSES_PER_DAY = 3;

uint8_t doseHour[DOSES_PER_DAY] = {8, 13, 20};
uint8_t doseMinute[DOSES_PER_DAY] = {0, 0, 0};
RTC_DS3231 rtc;
Adafruit_FRAM_I2C fram;
DFRobot_RGBLCD1602 lcd(0x60, 16, 2);

struct Button { uint8_t pin; bool stable = HIGH; bool raw = HIGH; unsigned long changedAt = 0; };
Button confirmButton{CONFIRM_PIN}, setButton{SET_PIN}, nextButton{NEXT_PIN};
bool alarmActive = false, framPresent = false, configuring = false;
int8_t activeDose = -1;
bool doseTriggered[DOSES_PER_DAY] = {false, false, false};
uint8_t lastDay = 0, configDose = 0, configField = 0;
unsigned long lastScreenAt = 0;
String lastLine1, lastLine2;
const uint16_t FRAM_MAGIC_ADDR = 0, FRAM_COUNT_ADDR = 2, FRAM_LOG_ADDR = 16;
const uint8_t LOG_RECORD_SIZE = 8;
const uint16_t MAX_LOGS = 4000;

bool pressed(Button &b) {
  bool raw = digitalRead(b.pin); unsigned long now = millis();
  if (raw != b.raw) { b.raw = raw; b.changedAt = now; }
  if (now - b.changedAt > 35 && raw != b.stable) { b.stable = raw; return b.stable == LOW; }
  return false;
}
String two(uint8_t n) { return n < 10 ? "0" + String(n) : String(n); }
String pad16(String s) { while (s.length() < 16) s += ' '; return s.substring(0, 16); }
void showScreen(const String &a, const String &b, bool force = false) {
  String x = pad16(a), y = pad16(b);
  if (force || x != lastLine1) { lcd.setCursor(0, 0); lcd.print(x); lastLine1 = x; }
  if (force || y != lastLine2) { lcd.setCursor(0, 1); lcd.print(y); lastLine2 = y; }
}
void initializeLog() {
  if (fram.read(FRAM_MAGIC_ADDR) != 0x4D || fram.read(FRAM_MAGIC_ADDR + 1) != 0x52) {
    fram.write(FRAM_MAGIC_ADDR, 0x4D); fram.write(FRAM_MAGIC_ADDR + 1, 0x52);
    fram.write(FRAM_COUNT_ADDR, 0); fram.write(FRAM_COUNT_ADDR + 1, 0);
  }
}
uint16_t logCount() { return uint16_t(fram.read(FRAM_COUNT_ADDR)) | (uint16_t(fram.read(FRAM_COUNT_ADDR + 1)) << 8); }
void setLogCount(uint16_t c) { fram.write(FRAM_COUNT_ADDR, c & 0xFF); fram.write(FRAM_COUNT_ADDR + 1, c >> 8); }
void writeLog(uint8_t dose, const DateTime &now) {
  if (!framPresent) return;
  uint16_t count = logCount(), address = FRAM_LOG_ADDR + (count % MAX_LOGS) * LOG_RECORD_SIZE;
  uint32_t stamp = now.unixtime();
  for (uint8_t i = 0; i < 4; i++) fram.write(address + i, (stamp >> (8 * i)) & 0xFF);
  fram.write(address + 4, dose); fram.write(address + 5, 0xA5); fram.write(address + 6, (stamp ^ dose) & 0xFF); fram.write(address + 7, 0x5A);
  setLogCount(count == 65535 ? 0 : count + 1);
  Serial.print("CONFIRMADA,"); Serial.print(now.timestamp(DateTime::TIMESTAMP_FULL)); Serial.print(",dosis "); Serial.println(dose + 1);
}
void printLog() {
  if (!framPresent) { Serial.println("FRAM no disponible"); return; }
  uint16_t count = logCount(), entries = count < MAX_LOGS ? count : MAX_LOGS, first = count < MAX_LOGS ? 0 : count % MAX_LOGS;
  Serial.println("LOG DE CONFIRMACIONES");
  for (uint16_t i = 0; i < entries; i++) {
    uint16_t a = FRAM_LOG_ADDR + ((first + i) % MAX_LOGS) * LOG_RECORD_SIZE;
    if (fram.read(a + 5) != 0xA5 || fram.read(a + 7) != 0x5A) continue;
    uint32_t stamp = uint32_t(fram.read(a)) | (uint32_t(fram.read(a + 1)) << 8) | (uint32_t(fram.read(a + 2)) << 16) | (uint32_t(fram.read(a + 3)) << 24);
    Serial.print(DateTime(stamp).timestamp(DateTime::TIMESTAMP_FULL)); Serial.print(",dosis "); Serial.println(fram.read(a + 4) + 1);
  }
}
void handleSerial() {
  if (!Serial.available()) return;
  String c = Serial.readStringUntil('\n'); c.trim(); c.toUpperCase();
  if (c == "LOG") printLog();
  else if (c.startsWith("SET ") && c.length() >= 23) {
    rtc.adjust(DateTime(c.substring(4,8).toInt(), c.substring(9,11).toInt(), c.substring(12,14).toInt(), c.substring(15,17).toInt(), c.substring(18,20).toInt(), c.substring(21,23).toInt()));
    Serial.println("RELOJ AJUSTADO");
  } else Serial.println("Comandos: LOG | SET AAAA-MM-DD HH:MM:SS");
}
void startAlarm(uint8_t dose) { alarmActive = true; activeDose = dose; lcd.setRGB(255, 0, 0); showScreen("TOME MEDICACION", "PULSE CONFIRMAR", true); Serial.print("ALARMA,dosis "); Serial.println(dose + 1); }
void stopAlarm(const DateTime &now) { noTone(BUZZER_PIN); writeLog(activeDose, now); alarmActive = false; activeDose = -1; lcd.setRGB(0, 180, 0); showScreen("Toma registrada", "Gracias", true); }
void checkSchedule(const DateTime &now) {
  if (now.day() != lastDay) { lastDay = now.day(); for (uint8_t i = 0; i < DOSES_PER_DAY; i++) doseTriggered[i] = false; }
  if (alarmActive || configuring) return;
  for (uint8_t i = 0; i < DOSES_PER_DAY; i++) if (!doseTriggered[i] && now.hour() == doseHour[i] && now.minute() == doseMinute[i]) { doseTriggered[i] = true; startAlarm(i); break; }
}
void handleConfiguration() {
  if (pressed(setButton)) {
    if (!configuring) { configuring = true; configDose = 0; configField = 0; lcd.setRGB(0, 0, 180); }
    else if (configField == 0) configField = 1;
    else if (configDose < DOSES_PER_DAY - 1) { configDose++; configField = 0; }
    else { configuring = false; lcd.setRGB(0, 120, 0); Serial.println("HORARIOS ACTUALIZADOS"); }
  }
  if (configuring && pressed(nextButton)) { if (configField == 0) doseHour[configDose] = (doseHour[configDose] + 1) % 24; else doseMinute[configDose] = (doseMinute[configDose] + 5) % 60; }
}
void updateDisplay(const DateTime &now) {
  if (alarmActive) return;
  if (configuring) { showScreen("Dosis " + String(configDose + 1) + (configField == 0 ? " hora" : " min"), two(doseHour[configDose]) + ":" + two(doseMinute[configDose]) + " SIG cambia"); return; }
  if (millis() - lastScreenAt < 1000) return;
  lastScreenAt = millis(); lcd.setRGB(0, 120, 0);
  showScreen(two(now.hour()) + ":" + two(now.minute()) + "  " + two(now.day()) + "/" + two(now.month()), "SET: horarios");
}
void setup() {
  pinMode(BUZZER_PIN, OUTPUT); pinMode(CONFIRM_PIN, INPUT_PULLUP); pinMode(SET_PIN, INPUT_PULLUP); pinMode(NEXT_PIN, INPUT_PULLUP);
  Serial.begin(115200); Wire.begin();
  lcd.init(); lcd.setRGB(0, 120, 0); showScreen("Recordatorio", "Iniciando...", true);
  if (!rtc.begin()) { lcd.setRGB(255, 0, 0); showScreen("RTC no detectado", "Revise cables", true); while (true) delay(100); }
  if (rtc.lostPower()) rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  framPresent = fram.begin(0x50);
  if (framPresent) initializeLog(); else { lcd.setRGB(255, 120, 0); showScreen("FRAM no detectada", "Log no guardado", true); delay(1500); }
  lastDay = rtc.now().day(); Serial.println("LISTO. Comandos: LOG | SET AAAA-MM-DD HH:MM:SS");
}
void loop() {
  handleSerial(); DateTime now = rtc.now();
  if (alarmActive) { tone(BUZZER_PIN, 2400); if (pressed(confirmButton)) stopAlarm(now); return; }
  handleConfiguration(); checkSchedule(now); updateDisplay(now);
}