Overview
IOT-101 (GitHub Repository) is an open-source repository of practical Internet of Things (IoT) projects, microcontroller firmware, and workflow automations. It demonstrates real-world sensor interfacing, hardware GPIO control, and connecting physical devices to cloud webhooks via n8n.
I built these projects to bridge hardware and software engineering—focusing on practical applications like home safety (kitchen gas leak detection), climate tracking, and automated alerting.
Key Hardware Modules & Practical Projects
- Kitchen Gas Leak Alarm: Interfaced the MQ-6 semiconductor gas sensor for detecting LPG, butane, and propane gas concentrations. When gas levels exceed a safety threshold, the Arduino triggers a loud buzzer, turns on an emergency red LED, and sends an alert webhook.
- Temperature & Climate Monitoring: Used the DHT11 sensor to measure temperature and humidity, calculating heat index values to trigger automated warnings during extreme summer heatwaves.
- Automatic Night Lighting: Implemented an analog Light Dependent Resistor (LDR) circuit that automatically turns on lighting when ambient room or street light falls below a set threshold.
- Infrared (IR) Remote Decoding: Decoded 38kHz signals from standard handheld IR remote controls, allowing buttons to switch physical relays and AC appliances on and off safely.
- Serial Telemetry Streaming: Wrote bidirectional serial communication protocols between the microcontroller and a host computer to stream live sensor readings into cloud dashboards.
Cloud Integration with n8n
Beyond running code on the microcontroller, the project demonstrates how to connect physical hardware to cloud software workflows:
- Webhook Alerts: When a sensor trips (e.g. gas leak detected), the gateway makes an HTTP POST request to an n8n automation workflow.
- Instant Notifications: The n8n workflow formats the message and delivers an instant alert to a private Telegram channel and sends an emergency email notification.
- Self-Hosted Setup: Designed to run easily on low-cost hardware like an Arduino, ESP32, or Raspberry Pi.
Tech Stack
| Layer | Tools | What it does |
|---|---|---|
| Hardware | Arduino Uno/Nano, ESP32 | Microcontroller GPIO control, analog-to-digital conversions. |
| Sensors | MQ-6, DHT11, LDR, IR Receiver | Measuring gas levels, temperature, humidity, and optical signals. |
| Firmware | C++, Arduino IDE | Real-time interrupt handlers, sensor debounce, and serial streaming. |
| Automation | n8n, Webhooks, Telegram API | Cloud workflow triggers and emergency smartphone notifications. |
Key Results
- Hands-On Sensor Interfacing: Practical, well-documented C++ code examples for common hardware sensors.
- Connected Automation: Real-time bridge from physical sensor pins to cloud webhooks and chat notifications.
- Open Source Reference: Easy for students, hobbyists, and engineers to learn embedded systems and automation.