1. Assignment -1 Real Time System Design Submitted By Komati Yamini 2301709006 Research Scholar Department of ECE Puducherry Technological University Puducherry

2. Automatic Coffee Vending Machine 1. Introduction he coffee maker embedded system represents a remarkable blend of technology and convenience, designed to streamline the process of brewing coffee. Found in countless homes and businesses, it is an essential kitchen appliance that has evolved over the years to cater to the diverse preferences of coffee enthusiasts. Here's an in-depth exploration of the coffee maker embedded system: i. Microcontroller or Microprocessor: At the core of the coffee maker system is a microcontroller or microprocessor. This component serves as the brain, overseeing the entire brewing process. It interprets user input, monitors sensors, and manages the various components, ensuring a seamless and controlled brewing experience. ii. User Interface: Coffee makers feature user-friendly interfaces, ranging from basic buttons and LED displays to more advanced touchscreens and mobile apps. These interfaces allow users to customize their coffee by selecting brewing options, adjusting coffee strength, and setting brewing timers. The embedded system translates these inputs into precise brewing instructions. iii. Sensors: Sensors play a critical role in the coffee maker system, measuring key parameters such as water temperature, water level, coffee grind size, and brewing time. These sensors provide real-time data that guides the embedded system in maintaining the desired brewing conditions, ensuring that the coffee is consistently brewed to perfection. iv. Control Algorithms: Control algorithms are the intelligent algorithms that dictate how the coffee maker operates. They adjust parameters like water flow rate, brewing time, and water temperature to match the user's selected settings. These algorithms are responsible for brewing coffee to the desired strength and flavor, providing a personalized experience. v. Coffee Grinder: For machines that grind coffee beans, an integrated coffee grinder is part of the system. It crushes beans to the user's preferred consistency, whether it's for espresso, drip coffee, or other brew types. vi. Water Heating Element: The system includes a heating element responsible for heating water to the appropriate temperature for brewing, ensuring that it falls within the ideal range for coffee extraction. vii. Brewing Mechanism: This component controls the infusion of hot water with ground coffee. It manages variables such as water flow, pressure, and brewing time to achieve the chosen coffee strength and flavor profile. viii. Safety Features: Safety is a paramount concern in coffee makers. The embedded system incorporates safety features such as automatic shut-off after a brewing cycle, overheat protection, and error detection to prevent accidents or damage to the machine. ix. Connectivity: Some advanced coffee makers offer connectivity options like Wi-Fi or Bluetooth, allowing users to control the machine remotely through a smartphone app. This

3. feature also enables users to check the status of the brewing process and even schedule brewing times in advance. x. Maintenance and Diagnostics: The embedded system often includes features for maintenance and diagnostics, such as indicating when it's time to descale the coffee maker, replace filters, or perform other routine tasks to keep the machine in optimal working condition. xi. Energy Efficiency: Coffee maker embedded systems are designed with energy efficiency in mind, automatically entering low-power states when not in use to conserve energy and reduce operating costs. The coffee maker embedded system represents a remarkable fusion of technology and the art of coffee brewing. It ensures consistency, convenience, and customization, providing coffee enthusiasts with a hassle-free brewing experience. As technology continues to advance, coffee makers are likely to incorporate even more features and innovations, further enhancing the coffee brewing experience for users worldwide. 2. Basic Block Diagram Figure 1: Basic Block Diagram of Coffee Vending Machine Description and Working:A coffee maker is a kitchen appliance that simplifies the process of brewing coffee. It consists of several key components, each playing a crucial role in producing a cup of coffee. Here's a description of the main components of a typical coffee maker:

4. 1.Water Reservoir: The water reservoir is where you pour in the water that will be used to brew the coffee. It typically has markings to indicate the water level, ensuring you add the right amount for your desired number of cups. 2.Coffee Filter: Coffee filters are used to hold the coffee grounds during the brewing process. They come in various forms, including paper filters or permanent, reusable metal or plastic filters. The coffee grounds are placed in the filter, and hot water is poured over them to extract the coffee. 3.Coffee Grounds Basket: The coffee grounds basket or holder is where you place the coffee filter with the coffee grounds. It is positioned above the coffee pot or carafe. After brewing, the used coffee grounds remain in this basket. 4.Heating Element: The heating element is responsible for heating the water to the appropriate temperature for brewing. In most coffee makers, this is a heating plate or a coil that warms the water before it's dripped or pumped over the coffee grounds. 5.Coffee Pot or Carafe: The coffee pot or carafe is where the brewed coffee is collected. It often features a handle for easy pouring and a spout to avoid spills. The capacity of the pot or carafe can vary, accommodating different serving sizes. 6.Control Panel or Interface: The control panel is the user interface of the coffee maker. It typically includes buttons, switches, and LED displays. On more advanced models, you might find digital screens and programmable settings for coffee strength and brewing times. 7.Heating Plate/Warmer: Some coffee makers have a heating plate or warmer on which the coffee pot or carafe sits. It keeps the brewed coffee warm after brewing, allowing you to pour multiple cups without the coffee cooling too quickly. 8.Water Pump: In some coffee makers, especially espresso machines, a water pump is used to force water through the coffee grounds with pressure. This creates espresso- style coffee and is distinct from the drip-style brewing found in most coffee makers. 9.Grinder (in some models): High-end coffee makers, especially those designed for espresso, may include an integrated coffee grinder. This component grinds whole coffee beans just before brewing, ensuring maximum freshness. 10.Water Filtration (in some models): Some coffee makers feature built-in water filtration systems to improve the taste of the coffee by removing impurities from the water. 11.Timer and Brewing Controls (in some models): Advanced coffee makers may have programmable features, allowing you to set a specific brewing time or adjust the strength of your coffee. 12.Milk Frothier (in some models): Espresso machines and specialty coffee makers may include a milk frothier or steam wand for creating frothed milk, making cappuccinos and lattes.

5. These components work together to brew coffee, and the specific features and functionalities can vary widely depending on the type and brand of coffee maker. Whether you prefer a simple drip coffee maker or a high-end espresso machine, understanding these components can help you select the right coffee maker to suit your brewing preferences. 3. Digital System Design Schematic: Designing a digital coffee vending machine involves various components, including sensors, microcontrollers, actuators, and user interfaces. Here's an overview of the digital system design for a coffee vending machine. It is a complex and requires careful consideration of each component's functionality and how they interact. Additionally, safety, reliability, and user-friendliness should be prioritized in the design. This design can serve as a foundation for building a fully functional digital coffee vending machine. Figure 2: Schematic presentation of Coffee machine Algorithm: Simplified algorithm for a typical coffee vending machine, which primarily serves standard coffee options: Step 1: Initialization •Start the vending machine. •Initialize the system, including all sensors, pumps, and displays. •Display a welcome message on the user interface. Step 2: User Interaction •Await user input through the user interface (e.g., touch screen or buttons).

6. •Present the user with coffee options (e.g., black coffee, cappuccino, latte). •Allow the user to select their desired coffee type. Step 3: Coffee Preparation •Based on the user's selection, the machine identifies the specific coffee recipe (e.g., the type of coffee, amount of water, and milk). Step 4: Coffee Ingredients •Check the availability of coffee beans, water, milk, and other ingredients. •If any ingredient is insufficient, display an "Out of Stock" message and go to Step 6. Step 5: Brewing Process •If all ingredients are available, start the coffee brewing process: •Grind coffee beans if required. •Heat water to the appropriate temperature. •Mix coffee grounds (if pre-ground) with hot water. •Froth milk if needed. •Serve the coffee into a cup. Step 6: Dispensing Coffee •Dispense the freshly brewed coffee into a cup. •Notify the user that their coffee is ready. •Optionally, ask the user if they'd like any additional options, such as sugar or creamer. Step 7: Payment (optional) •If the machine requires payment, prompt the user for payment. •Verify payment method (e.g., coin insertion, card swipe, mobile payment). •Release the coffee once payment is confirmed. Step 8: Cleanup •After the user has taken their coffee, the machine performs cleanup tasks: •Rinse and clean the coffee dispensing components. •Check for any spills and clean the dispensing area. •Update ingredient levels and display any "Refill" messages for low ingredients. Step 9: User Exit

7. •Display a message thanking the user for their purchase. •Provide an option for the user to request a receipt or another coffee. Step 10: Shutdown •If there are no more users, or after a period of inactivity, the machine can initiate a shutdown process. •Power off the machine and all components. This algorithm is a simplified representation of typical Real-world coffee vending machines. Depending on the complexity of the machine, the algorithm may be significantly more intricate, involving more sensors and subsystems to control the brewing process. 4. Flowchart: Figure 3: Flow chart of Typical Coffee Vending Machine

8. 5. Arduino Code for Coffee vending Machine with Microcontroller Board ATMEGA-16 – Arduino Board. The following is Program is based on Arduino C. #include <Keypad.h> #include <LiquidCrystal.h> LiquidCrystal lcd(8, 9, 4, 5, 6, 7); // LCD setup const byte ROWS = 4; //four rows const byte COLS = 4; //four columns char keys[ROWS][COLS] = { {'1', '2', '3', 'A'}, {'4', '5', '6', 'B'}, {'7', '8', '9', 'C'}, {'*', '0', '#', 'D'} }; byte rowPins[ROWS] = {A0, A1, A2, A3}; //connect to the row pinouts of the keypad byte colPins[COLS] = {A4, A5, A6, A7}; //connect to the column pinouts of the keypad Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS ); // Coffee options const int blackCoffeePrice = 2; const int cappuccinoPrice = 3; const int lattePrice = 4; int selectedCoffee = 0; int insertedCoins = 0; void setup() { lcd.begin(16, 2); // Initialize the LCD lcd.print("Select coffee:"); lcd.setCursor(0, 1); lcd.print("1. Black 2. Cappuccino 3. Latte"); } void loop() { char key = keypad.getKey(); if (key) { lcd.clear(); lcd.print("You selected: "); lcd.print(key); switch (key) { case '1':

9. selectedCoffee = blackCoffeePrice; break; case '2': selectedCoffee = cappuccinoPrice; break; case '3': selectedCoffee = lattePrice; break; default: lcd.clear(); lcd.print("Invalid selection"); delay(2000); lcd.clear(); lcd.print("Select coffee:"); lcd.setCursor(0, 1); lcd.print("1. Black 2. Cappuccino 3. Latte"); break; } if (selectedCoffee > 0) { lcd.setCursor(0, 1); lcd.print("Insert coins: $"); while (insertedCoins < selectedCoffee) { char coin = keypad.getKey(); if (coin >= '0' && coin <= '9') { insertedCoins = insertedCoins * 10 + (coin - '0'); lcd.print(coin); } } if (insertedCoins >= selectedCoffee) { dispenseCoffee(); insertedCoins -= selectedCoffee; selectedCoffee = 0; } else { lcd.clear(); lcd.print("Insufficient funds"); delay(2000); lcd.clear(); lcd.print("Select coffee:"); lcd.setCursor(0, 1); lcd.print("1. Black 2. Cappuccino 3. Latte"); } } }

10. } void dispenseCoffee() { lcd.clear(); lcd.print("Dispensing coffee"); delay(2000); // Simulate a 2-second dispensing process lcd.clear(); lcd.print("Enjoy your coffee!"); delay(2000); lcd.clear(); lcd.print("Select coffee:"); lcd.setCursor(0, 1); lcd.print("1. Black 2. Cappuccino 3. Latte"); } The specific design and functionality of automatic coffee vending machines can vary widely, with some machines offering more features and customization options than others. Advanced machines may also include remote monitoring, touchless payment options, and Wi-Fi connectivity for additional convenience.