Waffle Detection System - The Perfect Time To Leave A Stroop

Made by eamonmagd / Food & Drinks

About the project

Project info

Difficulty: Easy

Platforms: Arduino

Estimated time: 2 hours

License: GNU General Public License, version 3 or later (GPL3+)

Items used in this project

Hardware components

	DHT11 Basic Temp Humidity Sensor	x 1
	Gravity: I2C LCD1602 Arduino LCD Display Module (Green)	x 1
	Grove - Passive Buzzer	x 1

Software apps and online services

	pycharm
	Arduino
	anaconda

Story

Introduction

This report details the functionalities and components of a Stroopwafel detection system implemented using an Arduino. The system uses various sensors and outputs to detect specific conditions and respond accordingly. The primary components include a temperature sensor (LM35), a DHT11 temperature and humidity sensor, an LCD display, a buzzer, and an LED. Additionally, a linear regression model was used to validate the system's performance through multiple tests. I created a full video on this as well on YouTube where I go through the tests and ideas around the project.

Components and Setup

LCD Display (LiquidCrystal_I2C)

Purpose: To display temperature readings.
Pin Configuration: I2C address is set to 0x27 for a 16x2 character display.
Initialization: Initialized in the setup() function and configured to display text at specific cursor positions.

Temperature Sensor (LM35)

Purpose: To measure the ambient temperature.
Pin Configuration: Connected to analog pin A3.
Reading Mechanism: Analog readings are converted to voltage, then to temperature in Celsius.

DHT11 Sensor

Purpose: To measure temperature and humidity.
Pin Configuration: Connected to digital pin 2.
Library Used: The DHT sensor library is used for easy interfacing.

Buzzer

Reading Mechanism: Uses the libraryÃ¢â‚¬â„¢s function to get temperature readings.
Purpose: To play a melody (Tetris theme) under certain conditions.

LED

Purpose: To indicate a condition visually.
Pin Configuration: Connected to a digital pin.
Functionality: Turns on when a certain number of serial messages are received.
Pin Configuration: Connected to analog pin A1.Functionality: The buzzer plays the Tetris theme using predefined note frequencies and durations.

Serial Communication

Purpose: To receive messages that trigger specific actions.Configuration: Initialized at 9600 baud rate.

Code Functionality

Setup Function

Initializes the LCD display, sets up the buzzer and LED pins, and waits for sensors to stabilize.
Initializes the serial communication.

Loop Function

Continuously reads temperatures from both the LM35 and DHT11 sensors.
Displays these temperatures on the LCD.
Checks for a 20% reduction in the initial temperature reading from the LM35 sensor and plays the Tetris theme if detected.
Monitors the serial input for incoming messages, counting them, and triggers the buzzer and LED if more than 20 messages are received.

Temperature Reading Functions

readTemperature(): Reads and converts the analog value from the LM35 sensor to a temperature value.
readDHTTemperature(): Reads the temperature from the DHT11 sensor using its library functions.

Music Playback

playTetrisTheme(): Contains the sequence of notes and durations for the Tetris theme. It plays the melody using the buzzer.

Serial Message Handling

Counts the number of messages received via the serial port.
If the count exceeds 20, the system plays the Tetris theme and blinks the LED for visual indication.

Motion Detection System from Laptop

This Python script uses OpenCV to capture video from a webcam and detect movement by comparing consecutive frames. When movement is detected, it sends a signal ('1') to an Arduino via serial communication at a baud rate of 9600. The script processes video frames in grayscale, applies Gaussian blur to reduce noise, computes the difference between frames, and uses contour detection to identify movement. This allows the Arduino to respond only when movement is detected, making the system efficient and responsive.

Temperature Reduction

The system tracks the percentage change in temperature from an initial reading.

A 20% reduction in temperature triggers the buzzer to play the Tetris theme.

Serial Message Count

The system counts the number of serial messages received.
Upon receiving more than 20 messages, the buzzer plays the Tetris theme and the LED blinks.

Serial Message Count

The answers for the best times from my controlled tests are below.

Conclusion

The Stroopwafel detection system is a multifaceted project combining temperature monitoring, user feedback via an LCD, and auditory/visual alerts. The integration of multiple sensors and outputs showcases the capability to create an interactive and responsive system. The core functionality is based on monitoring temperature changes and reacting to external inputs through serial communication, ensuring robust detection and alert mechanisms. Check out the full video on Youtube!

Schematics, diagrams and documents

Scematics for recreating the arduino side

Code

Python code for object detection

import cv2
import serial
import time

# Set up serial communication with the Arduino
# Replace '/dev/tty.usbmodem1431201' with the appropriate port name for your system
arduino = serial.Serial(port='/dev/tty.usbmodem1431201', baudrate=9600, timeout=1)

# Allow some time for the Arduino to initialize
time.sleep(2)

# Start video capture from the default webcam (0 is the default webcam index)
cap = cv2.VideoCapture(0)

# Check if the camera opened successfully
if not cap.isOpened():
    print("Error: Could not open camera.")
    exit()

# Read the first frame
ret, prev_frame = cap.read()
if not ret:
    print("Error: Could not read frame from camera.")
    cap.release()
    cv2.destroyAllWindows()
    exit()

# Convert the first frame to grayscale
prev_frame_gray = cv2.cvtColor(prev_frame, cv2.COLOR_BGR2GRAY)
prev_frame_gray = cv2.GaussianBlur(prev_frame_gray, (21, 21), 0)

while True:
    # Capture frame-by-frame
    ret, frame = cap.read()
    if not ret:
        print("Error: Could not read frame.")
        break

    # Convert current frame to grayscale
    frame_gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    frame_gray = cv2.GaussianBlur(frame_gray, (21, 21), 0)

    # Compute the absolute difference between the current frame and the previous frame
    frame_diff = cv2.absdiff(prev_frame_gray, frame_gray)

    # Threshold the difference to get the binary image
    _, thresh = cv2.threshold(frame_diff, 25, 255, cv2.THRESH_BINARY)
    thresh = cv2.dilate(thresh, None, iterations=2)

    # Find contours in the binary image
    contours, _ = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

    # If contours are found, movement is detected
    if len(contours) > 0:
        print("Movement detected!")
        arduino.write(b'1')  # Send a signal to the Arduino
    else:
        print("No movement")

    # Display the original frame and the threshold frame (optional)
    cv2.imshow('Frame', frame)
    cv2.imshow('Threshold', thresh)

    # Update the previous frame
    prev_frame_gray = frame_gray.copy()

    # Press 'q' to quit
    if cv2.waitKey(1) == ord('q'):
        break

# Release capture and close all windows
cap.release()
cv2.destroyAllWindows()

# Close the serial connection
arduino.close()

waffle arduino code

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

// Constants for the LCD
LiquidCrystal_I2C lcd(0x27, 16, 2); // set the LCD address to 0x27 for a 16 chars and 2 line display
const int tempPin = A3; // analog pin for the temperature sensor

// Constants for the buzzer
const int buzzerPin = A1;

// Define note frequencies (in Hz)
#define NOTE_B0 31
#define NOTE_C1 33
#define NOTE_CS1 35
#define NOTE_D1 37
#define NOTE_DS1 39
#define NOTE_E1 41
#define NOTE_F1 44
#define NOTE_FS1 46
#define NOTE_G1 49
#define NOTE_GS1 52
#define NOTE_A1 55
#define NOTE_AS1 58
#define NOTE_B1 62
#define NOTE_C2 65
#define NOTE_CS2 69
#define NOTE_D2 73
#define NOTE_DS2 78
#define NOTE_E2 82
#define NOTE_F2 87
#define NOTE_FS2 93
#define NOTE_G2 98
#define NOTE_GS2 104
#define NOTE_A2 110
#define NOTE_AS2 117
#define NOTE_B2 123
#define NOTE_C3 131
#define NOTE_CS3 139
#define NOTE_D3 147
#define NOTE_DS3 156
#define NOTE_E3 165
#define NOTE_F3 175
#define NOTE_FS3 185
#define NOTE_G3 196
#define NOTE_GS3 208
#define NOTE_A3 220
#define NOTE_AS3 233
#define NOTE_B3 247
#define NOTE_C4 262
#define NOTE_CS4 277
#define NOTE_D4 294
#define NOTE_DS4 311
#define NOTE_E4 330
#define NOTE_F4 349
#define NOTE_FS4 370
#define NOTE_G4 392
#define NOTE_GS4 415
#define NOTE_A4 440
#define NOTE_AS4 466
#define NOTE_B4 494
#define NOTE_C5 523
#define NOTE_CS5 554
#define NOTE_D5 587
#define NOTE_DS5 622
#define NOTE_E5 659
#define NOTE_F5 698
#define NOTE_FS5 740
#define NOTE_G5 784
#define NOTE_GS5 831
#define NOTE_A5 880
#define NOTE_AS5 932
#define NOTE_B5 988
#define NOTE_C6 1047
#define NOTE_CS6 1109
#define NOTE_D6 1175
#define NOTE_DS6 1245
#define NOTE_E6 1319
#define NOTE_F6 1397
#define NOTE_FS6 1480
#define NOTE_G6 1568
#define NOTE_GS6 1661
#define NOTE_A6 1760
#define NOTE_AS6 1865
#define NOTE_B6 1976
#define NOTE_C7 2093
#define NOTE_CS7 2217
#define NOTE_D7 2349
#define NOTE_DS7 2489
#define NOTE_E7 2637
#define NOTE_F7 2794
#define NOTE_FS7 2960
#define NOTE_G7 3136
#define NOTE_GS7 3322
#define NOTE_A7 3520
#define NOTE_AS7 3729
#define NOTE_B7 3951
#define NOTE_C8 4186
#define NOTE_CS8 4435
#define NOTE_D8 4699
#define NOTE_DS8 4978

// Notes of the Tetris theme (Korobeiniki)
int melody[] = {
  NOTE_E5, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_A4, NOTE_A4,
  NOTE_C5, NOTE_E5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_C5, NOTE_D5, NOTE_E5,
  NOTE_C5, NOTE_A4, NOTE_A4, NOTE_D5, NOTE_F5, NOTE_A5, NOTE_G5, NOTE_F5,
  NOTE_E5, NOTE_C5, NOTE_E5, NOTE_D5, NOTE_C5, NOTE_B4, NOTE_B4, NOTE_C5,
  NOTE_D5, NOTE_E5, NOTE_C5, NOTE_A4, NOTE_A4
};

// Note durations: 4 = quarter note, 8 = eighth note, etc.
int noteDurations[] = {
  4, 8, 8, 4, 8, 8, 4, 4,
  4, 4, 4, 8, 8, 4, 8, 8,
  4, 4, 4, 4, 4, 2, 4, 8,
  8, 4, 8, 8, 4, 4, 4, 8,
  8, 4, 8, 8, 4, 4
};

void playTetrisTheme() {
  for (int thisNote = 0; thisNote < sizeof(melody) / sizeof(melody[0]); thisNote++) {
    int noteDuration = 1000 / noteDurations[thisNote];
    tone(buzzerPin, melody[thisNote], noteDuration);
    delay(noteDuration * 1.50); // Adding a longer pause for slower tempo
    noTone(buzzerPin);
  }
}

void setup() {
  lcd.init();         // initialize the lcd
  lcd.backlight();    // Turn on the LCD screen backlight
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  pinMode(buzzerPin, OUTPUT);
  delay(2000); // Wait for the sensor to stabilize

  // Initialize the initial temperature
  initialTemperature = readTemperature();

  // Initialize serial communication at 9600 baud
  Serial.begin(9600);
}

float readTemperature() {
  int tempReading = analogRead(tempPin);
  float voltage = tempReading * (5.0 / 1023.0);
  return voltage * 100.0; // LM35 outputs 10mV per degree Celsius
}

float initialTemperature = 0.0;
int messageCount = 0;

void loop() {
  static bool musicPlayed = false;
 
  float currentTemperature = readTemperature();

  // Display the temperature on the LCD
  lcd.setCursor(6, 0);
  lcd.print(currentTemperature);
  lcd.print(" C   "); // Add some spaces to ensure old values are cleared

  // Check for 20% reduction
  if (!musicPlayed && currentTemperature <= initialTemperature * 0.8) {
    playTetrisTheme(); // Play the Tetris theme
    musicPlayed = true; // Ensure the music is played only once
  }

  // Check for serial messages
  if (Serial.available() > 0) {
    Serial.read(); // Read the incoming byte (message)
    messageCount++; // Increment the message count
  }

  // Check if message count exceeds 20
  if (messageCount > 20) {
    playTetrisTheme(); // Play the Tetris theme
    messageCount = 0; // Reset the message count to prevent retriggering
  }

  delay(1000); // Update the temperature reading every second
}

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Waffle Detection System - The Perfect Time To Leave A Stroop

About the project

Project info

Items used in this project

Hardware components

Software apps and online services

Story

Introduction

Components and Setup

LCD Display (LiquidCrystal_I2C)

Temperature Sensor (LM35)

DHT11 Sensor

Buzzer

LED

Code Functionality

Setup Function

Loop Function

Temperature Reading Functions

Music Playback

Serial Message Handling

Motion Detection System from Laptop

Temperature Reduction

Temperature Reduction

Serial Message Count

Conclusion

Schematics, diagrams and documents

Scematics for recreating the arduino side

Code

Python code for object detection

waffle arduino code

Credits

eamonmagd

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