Intelligent pet feeding system based on STM32

 An intelligent pet feeding system based on an STM32 microcontroller can automate the process of feeding pets at scheduled times or based on specific conditions (e.g., pet proximity, food level, etc.). Below is a detailed explanation of how to design and implement such a system:

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System Overview

The system will consist of the following components:

1. STM32 Microcontroller: Acts as the brain of the system, controlling all peripherals and logic.

2. Servo Motor or Stepper Motor: Dispenses food from the storage container.

3. Ultrasonic Sensor or Load Cell: Measures the food level in the container.

4. Real-Time Clock (RTC): Keeps track of time for scheduled feeding.

5. Infrared (IR) Sensor or Motion Sensor: Detects the presence of the pet.

6. LCD Display or LEDs: Provides status information (e.g., feeding time, food level).

7. Wi-Fi/Bluetooth Module (Optional): Enables remote control and monitoring via a smartphone app.

8. Buzzer: Alerts the pet during feeding time.

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Hardware Components

1. STM32 Development Board: e.g., STM32F4 Discovery or STM32 Nucleo.

2. Servo Motor: To control the food dispenser mechanism.

3. HC-SR04 Ultrasonic Sensor: To measure food level.

4. DS3231 RTC Module: For accurate timekeeping.

5. PIR Motion Sensor: To detect pet presence.

6. 16x2 LCD Display: To show system status.

7. ESP8266 Wi-Fi Module (Optional): For IoT connectivity.

8. Buzzer: For alerts.

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System Design

1. Food Dispensing Mechanism

• A servo motor rotates a flap or opens a gate to dispense food from the storage container.

• The STM32 controls the servo motor using PWM (Pulse Width Modulation).

2. Food Level Monitoring

• An ultrasonic sensor measures the distance to the food surface in the container. As the food level decreases, the distance increases.

• Alternatively, a load cell can measure the weight of the food.

3. Scheduled Feeding

• The RTC module keeps track of time, and the STM32 triggers feeding at predefined times.

4. Pet Detection

• A PIR motion sensor detects the pet's presence near the feeder. Feeding can be triggered automatically when the pet is detected.

5. User Interface

• An LCD display shows the current time, food level, and feeding schedule.

• LEDs or a buzzer can indicate low food levels or feeding events.

6. Remote Control (Optional)

• A Wi-Fi module (e.g., ESP8266) enables remote control and monitoring via a smartphone app or web interface.

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STM32 Code Implementation

Below is a simplified example of the STM32 code for the system:

c

#include "stm32f4xx_hal.h"
#include "lcd.h"
#include "servo.h"
#include "ultrasonic.h"
#include "rtc.h"
#include "pir.h"

// Function prototypes
void SystemClock_Config(void);
void MX_GPIO_Init(void);
void Feed_Pet(void);
void Check_Food_Level(void);
void Check_Schedule(void);

int main(void) {
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    LCD_Init();
    Servo_Init();
    Ultrasonic_Init();
    RTC_Init();
    PIR_Init();

    while (1) {
        Check_Food_Level();  // Monitor food level
        Check_Schedule();    // Check feeding schedule
        if (PIR_Detect()) {  // Check for pet presence
            Feed_Pet();      // Dispense food
        }
        HAL_Delay(1000);    // Wait for 1 second
    }
}

// Feed the pet
void Feed_Pet(void) {
    LCD_Display("Feeding Pet...");
    Servo_Rotate(90);  // Open food dispenser
    HAL_Delay(2000);   // Wait for food to dispense
    Servo_Rotate(0);   // Close food dispenser
    LCD_Display("Feeding Complete");
}

// Check food level
void Check_Food_Level(void) {
    float distance = Ultrasonic_Measure();
    if (distance > 20.0) {  // Threshold for low food level
        LCD_Display("Low Food Level!");
        HAL_GPIO_WritePin(BUZZER_GPIO_Port, BUZZER_Pin, GPIO_PIN_SET);  // Sound buzzer
    } else {
        HAL_GPIO_WritePin(BUZZER_GPIO_Port, BUZZER_Pin, GPIO_PIN_RESET);  // Turn off buzzer
    }
}

// Check feeding schedule
void Check_Schedule(void) {
    RTC_TimeTypeDef currentTime;
    HAL_RTC_GetTime(&hrtc, &currentTime, RTC_FORMAT_BIN);

    // Example: Feed at 8:00 AM and 6:00 PM
    if ((currentTime.Hours == 8 && currentTime.Minutes == 0) ||
        (currentTime.Hours == 18 && currentTime.Minutes == 0)) {
        Feed_Pet();
    }
}

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Python Script for Remote Monitoring (Optional)

If you add a Wi-Fi module, you can use Python to create a remote monitoring and control interface.

Python Code Example

python

import socket
import time

# Connect to the STM32 via Wi-Fi
def connect_to_feeder():
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect(('192.168.1.100', 80))  # Replace with STM32's IP address
    return s

# Send a command to feed the pet
def feed_pet(s):
    s.send(b'FEED')
    response = s.recv(1024)
    print(response.decode())

# Main loop
if __name__ == "__main__":
    s = connect_to_feeder()
    while True:
        command = input("Enter command (feed/status): ").strip().lower()
        if command == "feed":
            feed_pet(s)
        elif command == "status":
            s.send(b'STATUS')
            response = s.recv(1024)
            print(response.decode())
        time.sleep(1)

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System Workflow

1. Scheduled Feeding: The RTC triggers feeding at predefined times.

2. Pet Detection: The PIR sensor detects the pet and triggers feeding.

3. Food Level Monitoring: The ultrasonic sensor alerts when food is low.

4. User Feedback: The LCD displays system status, and the buzzer alerts for low food.

5. Remote Control (Optional): The Wi-Fi module enables remote feeding and monitoring.

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Enhancements

• Mobile App: Develop a mobile app for remote control and monitoring.

• Food Type Selection: Add multiple food compartments and allow selection via the app.

• Voice Alerts: Use a speaker to play voice alerts for feeding time.

• Data Logging: Log feeding times and food levels for analysis.

This intelligent pet feeding system provides a convenient and automated solution for pet owners, ensuring their pets are fed on time and monitored effectively.