4. Embedded Programming

// Write to slashes to comment
// This code is on C++
// First we declare our constants in this case the led and the button

const int ledPin = 17; // The number represents the pin it is connected
const int buttonPin = 4; //If you connect it to another pin other that the one specified it wont work

void setup() {  // Void setup is a function that runs just one time, at the beginning (when it powers or resets)
  Serial.begin(115200); // The serial begin starts communication at 115200 bits per secong whcih is a pretty good velocity
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {// Void loop is a function that runs continuosly

  if (digitalRead(buttonPin) == LOW) { // If the button pressed (low)
    digitalWrite(ledPin, HIGH); // the led will turn on (high)
    Serial.println("Led On"); // Prints a message to the serial monitor

  } else {  // If the button not pressed it will happen the contrary
    digitalWrite(ledPin, LOW);
    Serial.println("Led Off");
  }

  delay(400); // A small delay so the serial output prints slower
}

//Include is used to call libraries with either #include  or "name"
//They allow use to use pre-written functions

#include  // it allow us to comunicate with the screen and time module 
#include  // to control the LCD screen
#include  // To control the real time module (in this case DS1307)
#include  // to control the servo

//Configuration
LiquidCrystal_I2C lcd(0x27, 20, 4);  //(Adress LCD, columns of the screen, rows on screen)
RTC_DS1307 rtc; //no need of parenthesis the I2C address is fixed internally
Servo ServoCross; // Creates a servo object (I name it cross because I changed the horn to be a cross)

//The pin of each component, I asked ChatGPT which connections were better for each one
//The const int (constat integer) is to define a value that cant change later on
const int pinServo = 18; // Pin tyoe Output  PWM capable (Pulse width modulation)
const int pinBuzzer = 19; //Output (PWD)
const int pinLED = 5; //Output

//Inputs (when we prees the button the ESP32 reads the signal either LOW or HIGH)
const int btnConf = 27; //Changes if we are introducing the hours (H) or minutes (M) or if its on standby
const int btnUp = 14; // The numbers go up
const int btnDown = 12; // The numbers go down

//Control pins for the bipolar stepper motor
const int stepPin = 32; // Contros the steps by readyn the pulses HIGH and LOW (each pulse is one step)
const int dirPin = 33; // Controls direction (HIGH is clockwise while LOW is the opposite)

// Star Wars Imperial Song for the alarm
int melodia[] = {  // Int for whole numbers withou decimals can be positve or negative 
  440, 440, 440, //Number of Hertz; I asked ChatGPT for the Hz equivalent of the notes similar to the imperial march song
  349, 523, 440, 
  349, 523, 440,
  659, 659, 659,
  698, 523, 415, 349
};

int duraciones[] = { 
  75, 75, 75, // reduced duration for faster melody
  50, 25, 100, 
  50, 25, 125,
  75, 75, 75,
  50, 40, 75, 125 // The number of durations are the same as the number of notes we have
};

const int totalNotas = 16; //Total of notes 

// Melody variables, without them we wouldnt know the next note or the program would read the same note
int notaActual = 0; // The note that is currently playing 
unsigned long tiempoNota = 0; // The time the note started, unsigned long is use for postive whole numbers

// Clock and alarm variables
int alarmaHora = 0; //Hour 
int alarmaMinuto = 0; //Minute

bool editandoAlarma = false; //Bool means true or false, true if edits the alarm
bool editandoHora = true; // True if we are editing the hour, false if it is the minute
bool sonando = false; // true when the alarm activates
bool showThatsAll = false; // true to display "that's all for now" after stopping

unsigned long debounceTiempo = 0; //Prevents button bouncing (false/multiple triggering)

// Servo variables
int posServo = 0; //Position of the servo (angle from 0 to 180 degrees)
unsigned long tiempoServo = 0; //Timing of its movement

//Stepper variables
int pasosStepper = 0; // Counts how many steps it moves 
bool dirStepper = true; //Direction of rotation
//Main difference between stepper (open loop) and servo (closed loop)

//function to reset the stepper
void resetStepper() {
  pasosStepper = 0;
  dirStepper = true;
}

//Set up funtion (runs once at the beginning, help us define the prevous variables when the programm starts)
void setup() { 

  Serial.begin(115200); // INICIA COMUNICACIÓN REMOTA SIMPLE
  //pin mode help us define if the pins are inputs or outputs
  pinMode(pinBuzzer, OUTPUT);
  pinMode(pinLED, OUTPUT);
  pinMode(stepPin, OUTPUT);
  pinMode(dirPin, OUTPUT);
  
  pinMode(btnConf, INPUT_PULLUP); //with the pull up the button pins have internal resistors
  pinMode(btnUp, INPUT_PULLUP); //This way we wont need physical resitors
  pinMode(btnDown, INPUT_PULLUP);

  ServoCross.attach(pinServo); //attach the pin (in this case 18) to control a servo
  ServoCross.write(0); // so it starts at 0 degrees

  lcd.init(); //Initialices the LCD screen
  lcd.backlight(); //Turn on LCD
  rtc.begin(); //start the Rtc module
}

//Runs repeadtly forever 
void loop() {

  DateTime now = rtc.now(); //Current real time

  manejarBotones(); // A function that check the buttons status

  pantallaPrincipal(now); // the function that show the hour
  verificarAlarma(now);// to check if the alarm must sound
}

//Buttons

void manejarBotones() { //each if in here is a diferent task, indepent from eachother 
//When we use the buttons the programm need to check several things at the same time
  if (millis() - debounceTiempo < 30) return; // faster button change

  // Edit or change mode of edition (editing alarm)
  if (digitalRead(btnConf) == LOW) { //Conf button is the green one, when pressed is LOW
    editandoAlarma = !editandoAlarma; //Changes between the alarm conf or standby
    if (editandoAlarma) { 
      editandoHora = !editandoHora; //changes between changing the hour or the minutes in the alarm conf
    }
    debounceTiempo = millis();
  }

  if (editandoAlarma) { //Here we include the actions of the other buttons activated by editing the alarm

  //Add numbers
    if (digitalRead(btnUp) == LOW) { //button up is the blue one, if pressed is on low 
      if (editandoHora) {
        alarmaHora = (alarmaHora + 1) % 24; //Adds one number and if we pass the 24 (hrs) resets to 0
      } else {
        alarmaMinuto = (alarmaMinuto + 1) % 60; //Same but for minututes 
      }
      debounceTiempo = millis(); //Prevents bouncing
    }

  //Substract numbers
    if (digitalRead(btnDown) == LOW) { //red button
      if (editandoHora) { 
        alarmaHora--;
        if (alarmaHora < 0) alarmaHora = 23; //same but substract one number at the time
      } else {
        alarmaMinuto--;
        if (alarmaMinuto < 0) alarmaMinuto = 59;
      }
      debounceTiempo = millis();
    }
  }
}

// LCD Screen

void pantallaPrincipal(DateTime t) { //parameter that prints the rtc current time

  lcd.setCursor(0, 0); //the starting point of the cursor
  lcd.print("HORA: "); // Writes the word time on the lcd
  imprimirDosDigitos(t.hour()); lcd.print(":"); //prints 2 digits of the time (hours)
  imprimirDosDigitos(t.minute()); lcd.print(":"); //same but for minutes
  imprimirDosDigitos(t.second()); //prints the seconds (real time)

  lcd.setCursor(0, 1); // starts at the first column second row
  lcd.print("ALARMA:  "); //prints the word alarm 
  imprimirDosDigitos(alarmaHora);
  lcd.print(":");//the word alarm is followed by the stablished one
  imprimirDosDigitos(alarmaMinuto);

  if (editandoAlarma) {
    lcd.print(editandoHora ? " " : " "); // what it shows if we are editing the alarm
  } else {
    lcd.print("        "); //clear the extra part if not editing
  }

  lcd.setCursor(0, 3); //third row for alarm messages
  if (sonando) {
    lcd.print(" !Take your pills!"); // show alarm message
    showThatsAll = true; // flag to show "that's all" after stop
  } else if (showThatsAll) {
    lcd.print(" That's all for now"); // show message after alarm stops
    showThatsAll = false; // reset flag
  } else {
    lcd.print("                    "); //clear row 3
  }
}

// Alarm

void verificarAlarma(DateTime now) { //checks if the current times (DateTimeNow) matches the alarm

  if (now.hour() == alarmaHora && 
      now.minute() == alarmaMinuto && 
      now.second() == 0) { //the exact second to start the alarm

//If the alarm is active (true)
    sonando = true;
    notaActual = 0; //it will start playing the melody on the first note
    tiempoNota = millis(); // record the start time of the note
    tone(pinBuzzer, melodia[0] / 4, duraciones[0] - 15); // starts the buzzer, divides the number to make the sound deeper

    // remote communication
    Serial.print("Alarma activada a las ");
    Serial.print(alarmaHora);
    Serial.print(":");
    Serial.println(alarmaMinuto);
  }

  if (sonando) { //if the alarm is active

    ejecutarAlarmaImperial(); //runs the melody we did before

    if (digitalRead(btnConf) == LOW || //if any of the buttons is pressed the alarm goes off
        digitalRead(btnUp) == LOW || // the two lines mean or, so if the blue button is pressed OR the green one it will stop
        digitalRead(btnDown) == LOW) { // with out the two line we woul lead to press the three buttons at the same time
      detenerAlarma();
    }
  }
}

// Alarm song and led
void ejecutarAlarmaImperial() {

  if (millis() - tiempoNota >= duraciones[notaActual]) {

    notaActual++;
    if (notaActual >= totalNotas) {
      notaActual = 0;
    }

    tone(pinBuzzer, melodia[notaActual] / 2, duraciones[notaActual] - 25);
    digitalWrite(pinLED, !digitalRead(pinLED)); //So the led follow the melody
    tiempoNota = millis();
  }

  if (millis() - tiempoServo >= 100) { //moves the servo every 100ms
    posServo += 20; // faster movement
    if (posServo >= 180) posServo = 0;
    ServoCross.write(posServo);
    tiempoServo = millis();
  }

  digitalWrite(dirPin, dirStepper); //Moves the stepper step by step, changes direction after 100 steps
  digitalWrite(stepPin, HIGH);
  delayMicroseconds(400); 
  digitalWrite(stepPin, LOW);
  delayMicroseconds(400);
  
  pasosStepper++;

  if (pasosStepper >= 100) {
    dirStepper = !dirStepper;
    pasosStepper = 0;
  }
}

// Stop the alarm

void detenerAlarma() {

  sonando = false; //stops the buzzer
  noTone(pinBuzzer);
  digitalWrite(pinLED, LOW); //turn off the led
  ServoCross.write(0); //resets the servo
  notaActual = 0; //resents the melody
  
  resetStepper(); //resets the stepper

  //Remote communication
  Serial.println("Alarma detenida, gracias por tomar tu medicamento!");
}

//Format

void imprimirDosDigitos(int numero) {
  if (numero < 10) lcd.print('0'); // makes numbers smaller than 10, two digit numbers by adding a cero at the start
  lcd.print(numero);
}