IoT Developer & Hardware Engineer Feb 2022 - Jun 2022

Smart Pet Potty Training System

An innovative IoT-based solution designed to automate and enhance pet potty training through intelligent monitoring and reward systems. The system uses a combination of high-precision load cells and moisture sensors to detect when pets use their designated area, automatically dispensing treats for positive reinforcement while providing real-time monitoring capabilities through a mobile app interface.

The project integrates hardware components like the Arduino Nano for local control and ESP32 for WiFi connectivity, with a custom-designed treat dispensing mechanism and comprehensive sensor array. The software stack includes C++ firmware for microcontrollers and Blynk IoT platform integration for remote monitoring and control.

Arduino Nano ESP32 Blynk IoT Load Cell Sensors C++ I2C Protocol Servo Control
Key Features

Automated Detection

Weight and moisture sensors for accurate usage detection

Mobile Control

Real-time monitoring and control via Blynk app

Data Analytics

Usage patterns and behavior tracking

System Architecture

System Design

graph TB subgraph Sensors LC[Load Cell Sensor] MS[Moisture Sensor] end subgraph Local_Control AN[Arduino Nano] LCD[LCD Display] TD[Treat Dispenser] BZ[Buzzer] end subgraph Connectivity ESP[ESP32 WiFi Module] end subgraph Cloud BP[Blynk Platform] MA[Mobile App] end LC -->|Weight Data| AN MS -->|Moisture Data| AN AN -->|Status| LCD AN -->|Control| TD AN -->|Alert| BZ AN <-->|Serial| ESP ESP <-->|WiFi| BP BP <-->|Real-time Data| MA style LC fill:#2f2f2f,stroke:#666 style MS fill:#2f2f2f,stroke:#666 style AN fill:#2f2f2f,stroke:#666 style LCD fill:#2f2f2f,stroke:#666 style TD fill:#2f2f2f,stroke:#666 style BZ fill:#2f2f2f,stroke:#666 style ESP fill:#2f2f2f,stroke:#666 style BP fill:#2f2f2f,stroke:#666 style MA fill:#2f2f2f,stroke:#666
Hardware

Hardware Components

Device Gallery

Main Control Unit
Main Control Unit
 Circuit Assembly
Circuit Assembly
Sensor Array

Functionality Demo

Live hardware demo Arduino Nano + ESP32

Core Components

Arduino Nano Pinout
  • Arduino Nano (Control Unit)
  • ESP32 (WiFi Module)
  • Load Cell + HX711
  • Moisture Sensor

Output Devices

ESP32 Pinout
  • I2C LCD Display
  • Piezo Buzzer
  • Servo Motor (Treat Dispenser)

Pin Connections

Arduino Nano

  • A1 → Moisture Sensor
  • A4/A5 → LCD (I2C)
  • D2 → Buzzer
  • D3 → Servo Motor
  • D4/D5 → Load Cell (HX711)

ESP32

  • GPIO16/17 → Serial Comm
  • VIN → 5V Power
  • GND → Common Ground
Software

Software Implementation

Firmware Features

  • Weight calibration and tare functionality
  • Moisture threshold detection
  • Treat dispensing logic
  • Serial communication protocol
pet_potty_firmware.ino C++ 
// Weight Sensor Calibration
void calibrateLoadCell() {
  LoadCell.begin();
  LoadCell.start(2000);
  LoadCell.setCalFactor(calibrationValue);

  // Tare the scale
  LoadCell.tare();
  Serial.println("Scale tared!");
}

// Moisture Detection
bool checkMoisture() {
  int moistureLevel = analogRead(MOISTURE_PIN);
  return moistureLevel > MOISTURE_THRESHOLD;
}

// Treat Dispensing
void dispenseTreat() {
  treatServo.write(DISPENSE_ANGLE);
  delay(500);
  treatServo.write(REST_ANGLE);
}

Blynk Integration

Component Widget Pin Function
Mode Slider V1 Operation Mode Control
Weight Gauge V2 Weight Display
Moisture Gauge V3 Moisture Level Display
Treat Status LED & Chart V4 Treat Dispenser Status
blynk_integration.ino C++ 
// Blynk Event Handlers
BLYNK_WRITE(V1) {
  operationMode = param.asInt();
}

BLYNK_WRITE(V2) {
  // Update weight display
  Blynk.virtualWrite(V2, currentWeight);
}

// Main Loop with Blynk
void loop() {
  Blynk.run();
  timer.run();

  if (LoadCell.update()) {
    currentWeight = LoadCell.getData();
    Blynk.virtualWrite(V2, currentWeight);
  }

  // Check moisture and update
  int moisture = analogRead(MOISTURE_PIN);
  Blynk.virtualWrite(V3, moisture);
}
Development

Development Process

Week 1

Project Planning

  • Initial concept development
  • Hardware component selection
  • System architecture design
  • Load cell research and testing
Week 2

Core Development

  • Circuit design and prototyping
  • Load cell and HX711 integration
  • Basic firmware implementation
  • Treat dispenser mechanism design
Week 3

IoT Integration

  • ESP32 WiFi setup
  • Blynk platform integration
  • Mobile app configuration
  • Real-time monitoring setup
Week 4

Completion

  • System testing and calibration
  • Performance optimization
  • Documentation creation
  • Final deployment
4 Weeks
Development Time
Rapid prototyping and implementation
8+
Components
Integrated hardware modules
500+
Code Base
Lines of embedded C++
95%
Success Rate
Detection accuracy
Resources

Project Resources

3D Models

Feeder tube and mechanical components

STL Format
Download STL

Circuit Diagrams

Complete electronics schematics

JPG Format 3 Files
Load Cell Diagram ESP32 Pinout Nano Pinout

Source Code

Arduino and ESP32 firmware

.ino Files 3 Files
Nano Code v7 ESP32 Code v2 I2C Scanner

Documentation

Setup guides and reference materials

PDF Format 3 Files
Blynk Setup Guide Load Cell Guide Load Cell Manual