Circuit Documentation

Summary

This circuit is designed to operate a medicine dispensing system that includes an Arduino UNO microcontroller, a 16x2 I2C LCD for display, a buzzer for audible alerts, a micro servo for mechanical actuation, a real-time clock (RTC) module for timekeeping, and pushbuttons for user input. The system is capable of dispensing medicine at predetermined times, with the ability to set and confirm these times using the pushbuttons. The RTC module ensures accurate timing, while the servo is used to release the medicine at the set times. The buzzer provides an audible signal when the medicine is dispensed.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Provides I/O pins for interfacing with other components
• Powers the circuit and controls the servo, buzzer, and LCD

16x2 I2C LCD

• Alphanumeric liquid crystal display with 16 characters by 2 lines
• Uses I2C communication to display information such as time and alarm settings

Buzzer

• An audible signaling device that emits a tone when activated
• Alerts the user when medicine is dispensed

Micro servo 9G

• A small-sized servo motor that provides precise control
• Actuates a mechanism to dispense medicine at set times

RTC DS3231

• A real-time clock module that maintains accurate time
• Provides time data to the Arduino for scheduling dispensing events

Pushbutton

• A momentary tactile switch used for user input
• Allows setting and confirming the dispensing times

Resistor (10k Ohms)

• A passive component used to limit current or divide voltages
• Used for pull-up resistors on the pushbutton inputs

Wiring Details

Arduino UNO

• 5V and GND pins provide power to the RTC DS3231, Micro servo 9G, 16x2 I2C LCD, and Pushbuttons
• A4 (SDA) and A5 (SCL) are used for I2C communication with the RTC DS3231 and 16x2 I2C LCD
• D9 controls the Micro servo 9G
• D6 connects to the Buzzer
• D2, D3, and D4 connect to Pushbuttons through 10k Ohm resistors

16x2 I2C LCD

• GND and VCC for power connections
• SDA and SCL for I2C data and clock lines

Buzzer

• POSITIVE connects to D6 on the Arduino UNO
• NEGATIVE connects to GND through a 10k Ohm resistor

Micro servo 9G

• GND and +5V for power connections
• PWM connects to D9 on the Arduino UNO

RTC DS3231

• GND and VCC for power connections
• SDA and SCL for I2C data and clock lines

Pushbutton

• One side connects to 5V
• The other side connects to an Arduino digital input (D2, D3, or D4) through a 10k Ohm resistor to GND

Resistor (10k Ohms)

• Connects between Pushbutton and GND
• Acts as a pull-up resistor for the Pushbutton inputs

Documented Code

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <RTClib.h>
#include <Servo.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);  // LCD address may vary, check yours
RTC_DS3231 rtc;
Servo dispenserServo;

const int buttonSetHour = 2;
const int buttonSetMinute = 3;
const int buttonConfirmTime = 4;
const int buzzerPin = 6;
const int servoPin = 9;

int alarmHours[3] = {8, 12, 20};  // Example dispensing times (8 AM, 12 PM, 8 PM)
int alarmMinutes[3] = {0, 0, 0};  // Corresponding minutes for each hour set
bool alarmTriggered[3] = {false, false, false}; // Tracks if alarm has triggered

void setup() {
  lcd.begin();
  rtc.begin();
  dispenserServo.attach(servoPin);
  pinMode(buzzerPin, OUTPUT);
  pinMode(buttonSetHour, INPUT_PULLUP);
  pinMode(buttonSetMinute, INPUT_PULLUP);
  pinMode(buttonConfirmTime, INPUT_PULLUP);

  lcd.print("Medicine Dispenser");
  delay(2000);
  lcd.clear();
}

void loop() {
  DateTime now = rtc.now();
  lcd.setCursor(0, 0);
  lcd.print("Time: ");
  lcd.print(now.hour());
  lcd.print(":");
  lcd.print(now.minute());
  lcd.print(":");
  lcd.print(now.second());

  // Check each alarm time
  for (int i = 0; i < 3; i++) {
    if (now.hour() == alarmHours[i] && now.minute() == alarmMinutes[i] && !alarmTriggered[i]) {
      dispenseMedicine(i);
      alarmTriggered[i] = true;  // Prevent retriggering in the same minute
    }
    if (now.minute() != alarmMinutes[i]) {
      alarmTriggered[i] = false; // Reset trigger for next day
    }
  }
  
  handleButtonInput();
}

void dispenseMedicine(int alarmIndex) {
  lcd.setCursor(0, 1);
  lcd.print("Dispensing Dose ");
  lcd.print(alarmIndex + 1);
  tone(buzzerPin, 1000);          // Sound buzzer
  dispenserServo.write(90);       // Rotate servo to release pills
  delay(1000);                    // Wait for pill to drop
  dispenserServo.write(0);        // Return servo to original position
  noTone(buzzerPin);
  delay(1000);  // Extra delay to ensure complete dispensing
}

void handleButtonInput() {
  static int settingHour = 8;
  static int settingMinute = 0;
  static int alarmSettingIndex = 0;

  // Increment hour setting
  if (digitalRead(buttonSetHour) == LOW) {
    settingHour = (settingHour + 1) % 24;
    delay(200);
  }

  // Increment minute setting
  if (digitalRead(buttonSetMinute) == LOW) {
    settingMinute = (settingMinute + 1) % 60;
    delay(200);
  }

  // Confirm time setting
  if (digitalRead(buttonConfirmTime) == LOW) {
    alarmHours[alarmSettingIndex] = settingHour;
    alarmMinutes[alarmSettingIndex] = settingMinute;
    alarmSettingIndex = (alarmSettingIndex + 1) % 3;  // Cycle through alarms

    lcd.setCursor(0, 1);
    lcd.print("Set Alarm ");
    lcd.print(alarmSettingIndex);
    lcd.print(": ");
    lcd.print(settingHour);
    lcd.print(":");
    lcd.print(settingMinute);
    delay(500);
  }
}

This code is responsible for controlling the medicine dispenser system. It initializes the LCD, RTC, servo, and sets up the button inputs with pull-up resistors. The main loop checks the current time against preset alarm times and triggers the dispenseMedicine function when it's time to dispense. The handleButtonInput function allows the user to set and confirm the dispensing times using the pushbuttons.