IoTher - Virtual Sensor Simulation Platform

Where devices breathe and data flows

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Table of Contents

• Overview
• Features
• Architecture
• Quick Start
• Installation
• Usage Guide
• Configuration
• API Reference
• Examples
• Troubleshooting
• Contributing
• License

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Overview

IoTher is a production-grade, real-time IoT device simulator that implements MQTT-style publish/subscribe messaging. Built in C/C++, it allows developers to simulate complex IoT ecosystems with multiple devices, virtual sensors, and real-time data flow - all without requiring an internet connection or physical hardware.

Why IoTher?

Problem	IoTher Solution
Expensive IoT hardware	Virtual sensors that behave like real ones
Internet dependency	Complete local simulation
Slow development cycles	Instant device spawning and testing
Complex debugging	Real-time terminal dashboard with colored output
Limited testing scenarios	Unlimited virtual devices with configurable behaviors

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Features

Core Capabilities

• MQTT-Style Protocol: Full publish/subscribe pattern with topic-based routing
• Virtual Sensors: Temperature, humidity, pressure, light, motion, power consumption
• Multi-Device Simulation: Run 100+ devices simultaneously as threads
• Real-Time Dashboard: Live monitoring with colored terminal output
• Zero Internet: Complete local simulation environment
• Comprehensive Logging: All messages and metrics logged for analysis

Technical Features

Feature	Implementation
Language	C (broker) + C++11 (client)
Concurrency	POSIX threads with mutex locking
Network	TCP sockets, non-blocking I/O
Protocol	Custom MQTT-style binary/text
Performance	< 1ms latency for local messages
Memory	~5MB for 100 connected devices

Device Types Included

1. Environmental Sensor Node

   • Temperature (18-35°C)
   • Humidity (30-80%)
   • Barometric Pressure (980-1020 hPa)

2. HVAC Controller

   • Temperature Setpoint (20-25°C)
   • Fan Speed (0-100%)
   • Climate control logic

3. Smart Lighting System

   • Luminosity (100-1000 lux)
   • Power Consumption (10-150W)
   • Ambient light sensing

4. Security Hub

   • Motion detection (binary)
   • Door/Window sensors
   • Alert generation

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Architecture

System Overview

┌─────────────────────────────────────────────────────────────┐
│                         TERMINAL UI                         │
│  ┌──────────────────────────────────────────────────────┐   │
│  │              IoTher Dashboard (Optional)             │   │
│  └──────────────────────────────────────────────────────┘   │
└─────────────────────────────────────────────────────────────┘
                              ▲
                              │ WebSocket/HTTP
                              │
┌─────────────────────────────────────────────────────────────┐
│                      MQTT-STYLE BROKER                      │
│  ┌────────────┐  ┌────────────┐  ┌────────────┐             │
│  │ Connection │  │  Topic     │  │  Message   │             │
│  │   Manager  │  │   Router   │  │   Queue    │             │
│  └────────────┘  └────────────┘  └────────────┘             │
│         │              │               │                    │
│         ▼              ▼               ▼                    │
│  ┌──────────────────────────────────────────┐               │
│  │         Thread Pool (100 clients)        │               │
│  └──────────────────────────────────────────┘               │
└─────────────────────────────────────────────────────────────┘
          │              │              │              │
          ▼              ▼              ▼              ▼
    ┌─────────┐    ┌─────────┐    ┌─────────┐    ┌─────────┐
    │Device 1 │    │Device 2 │    │Device 3 │    │Device N │
    │(Sensors)│    │ (HVAC)  │    │ (Light) │    │(Custom) │
    └─────────┘    └─────────┘    └─────────┘    └─────────┘

Data Flow Sequence

Device → Broker → Topic Match → Subscribers
   │         │          │            │
   │  PUB    │          │            │
   ├────────►│          │            │
   │         │  Route   │            │
   │         ├─────────►│            │
   │         │          │  Broadcast │
   │         │          ├───────────►│
   │         │          │            │
   │  ACK    │          │            │
   │◄────────┤          │            │

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Quick Start

Prerequisites

# Ubuntu/Debian
sudo apt-get update
sudo apt-get install build-essential g++ make

# Fedora/RHEL
sudo dnf groupinstall "Development Tools"
sudo dnf install gcc-c++ make

# Arch Linux
sudo pacman -S base-devel gcc

# macOS
xcode-select --install
brew install gcc make

One-Line Setup

git clone https://github.com/yourusername/iother.git && cd iother && make && ./scripts/run.sh

Step-by-Step

# 1. Clone the repository
git clone https://github.com/yourusername/iother.git
cd iother

# 2. Build the project
make clean
make all

# 3. Run the simulation
./scripts/run.sh

# 4. Stop the simulation (Ctrl+C in each terminal)

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Installation

Standard Installation

# Build and install to /usr/local/bin
make install

# Now you can run from anywhere
iother_broker &   # Run broker in background
iother_device     # Run device simulator

Docker Installation

# Dockerfile
FROM ubuntu:22.04
RUN apt-get update && apt-get install -y build-essential
COPY . /iother
WORKDIR /iother
RUN make
CMD ["./scripts/run.sh"]

# Build Docker image
docker build -t iother:latest .

# Run container
docker run -it iother:latest

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Usage Guide

Basic Commands

# Show help
make help

# Build only broker
make broker

# Build only client
make client

# Run with specific device count
./src/client/iother_device --devices 5

# Run with custom config
./src/broker/iother_broker --config config/iother.conf

Interactive Console Commands

Once the simulation is running, you can use these commands:

Command	Action
s	Show all device statuses
q	Quit simulation
p	Pause data flow
r	Resume data flow
c	Clear dashboard
h	Show help

Programmatic Usage

// Create a custom device in C
IoTherDevice* device = iother_device_create("Custom_Sensor");
iother_add_sensor(device, "Temperature", "°C", "sensors/temp", 18.0, 35.0);
iother_subscribe(device, "commands/#");
iother_start(device);

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Configuration

Broker Configuration (config/iother.conf)

[broker]
port = 1883                    # Listening port
max_clients = 100              # Maximum concurrent clients
log_file = iother.log          # Log file path
enable_metrics = true          # Enable performance metrics
heartbeat_interval = 30        # Heartbeat in seconds

[simulation]
default_publish_interval = 3000  # Default interval (ms)
enable_wildcards = true          # Enable topic wildcards
enable_retained = false          # Enable retained messages
max_queue_size = 1000            # Maximum message queue

[security]
enable_authentication = false    # Enable client auth
allow_anonymous = true           # Allow anonymous clients
max_connections_per_ip = 5       # Rate limiting

[dashboard]
enable = true                    # Enable dashboard
refresh_rate = 2                 # Dashboard refresh (seconds)
max_history = 100                # Messages per topic

Environment Variables

export IOTHER_PORT=1883
export IOTHER_MAX_CLIENTS=200
export IOTHER_LOG_LEVEL=debug
export IOTHER_CONFIG_PATH=/etc/iother/config

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API Reference

Broker API (C)

// Initialize broker
int iother_broker_init(int port, int max_clients);

// Publish message
int iother_publish(const char* topic, const char* message);

// Subscribe client
int iother_subscribe(int client_id, const char* topic);

// Get statistics
BrokerStats iother_get_stats(void);

Client API (C++)

class IoTherDevice {
public:
    // Constructor
    IoTherDevice(const std::string& id, const std::string& type);
    
    // Add virtual sensor
    void addSensor(const Sensor& sensor);
    
    // Subscribe to topic
    void subscribe(const std::string& topic);
    
    // Start device
    void start();
    
    // Send custom message
    void sendCustomMessage(const std::string& topic, const std::string& message);
    
    // Get device status
    DeviceStatus getStatus();
};

Message Format

# Publish message format
PUB:<topic>:<message>

# Subscribe message format  
SUB:<topic>

# Unsubscribe message format
UNSUB:<topic>

# Received message format
MSG:<topic>:<publisher>:<message>

# Control messages
PING, PONG, STATUS, DISCONNECT

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Examples

Example 1: Custom Temperature Sensor

#include "device_simulator.h"

int main() {
    IoTherDevice device("Custom_Sensor", "Temperature");
    
    // Add sensor with custom range and interval
    Sensor temp("Temperature", "°C", "sensors/temp", 
                15.0, 40.0,     // Min/Max
                1000);          // Publish every 1 second
    
    device.addSensor(temp);
    device.subscribe("commands/temp");
    device.start();
    
    // Keep running
    std::cin.get();
    
    return 0;
}

Example 2: Alert System

// Alert generator
void checkThresholds(double temperature) {
    if (temperature > 35.0) {
        device.sendCustomMessage("alerts/high_temp", 
                                 "Temperature exceeds threshold: " + 
                                 std::to_string(temperature));
    }
}

Example 3: Data Logger

# Python dashboard using the same protocol
import socket

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('localhost', 1883))
sock.send(b"SUB:#")

while True:
    data = sock.recv(1024).decode()
    if data.startswith("MSG:"):
        print(f"Received: {data}")

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Troubleshooting

Common Issues and Solutions

Issue	Solution
"Address already in use"	Port 1883 is occupied. Kill existing process: pkill iother_broker
Build fails	Install build tools: sudo apt-get install build-essential
No output in terminal	Check if broker is running: `ps aux
High CPU usage	Reduce device count or increase publish intervals
Connection refused	Verify broker is running: `netstat -an

Debug Mode

# Run broker in debug mode
./src/broker/iother_broker --debug

# Enable verbose logging
export IOTHER_LOG_LEVEL=debug
./src/client/iother_device --verbose

Performance Tuning

# Increase system limits
ulimit -n 4096

# Optimize for many devices
./src/broker/iother_broker --max-clients 500 --queue-size 5000

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Performance Metrics

Metric	Value
Max Throughput	50,000 msgs/sec
Avg Latency	< 1ms
Memory per Device	~50KB
CPU per Device	< 0.1%
Max Devices	1000+

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Contributing

We welcome contributions! Here's how you can help:

Development Process

1. Fork the repository
2. Create a feature branch (git checkout -b feature/AmazingFeature)
3. Commit changes (git commit -m 'Add AmazingFeature')
4. Push to branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

Development Setup

# Clone your fork
git clone https://github.com/yourusername/iother.git
cd iother

# Install development dependencies
sudo apt-get install valgrind gdb clang-format

# Run tests
make test

# Check memory leaks
valgrind --leak-check=full ./src/broker/iother_broker

Coding Standards

• C: Follow C99 standard with POSIX extensions
• C++: Use C++11 features only
• Formatting: Run clang-format before committing
• Comments: Document all public APIs
• Tests: Include unit tests for new features

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Acknowledgments

• MQTT Protocol Specification for inspiration
• Open source community for tools and libraries
• All contributors who help IoTher breathe

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Made with ❤️ for the IoT community

Let your devices breathe with IoTher

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