IoT Systems

MQTT, CoAP, and HTTP each have trade-offs in bandwidth, latency, battery, and reliability. You need to know when to use each and why. Lesson 1 benchmarks all three with the same sensor data so you can make informed decisions.

A broker is the backbone of any MQTT system. You will set up Mosquitto from scratch with TLS, authentication, ACLs, and persistence. You will also connect to cloud platforms like SiliconWit.io, a connected operations platform that accepts MQTT connections and provides dashboards, alerts, automation, and REST API access. You will understand both self-hosted and managed options.

Raw sensor data is useless without visualization and alerting. You will build dashboards with Grafana and InfluxDB, configure threshold alerts that notify via email, SMS, or Slack, and design automation rules that act without human intervention.

Most IoT tutorials skip security. This course dedicates an entire lesson to TLS, mutual authentication, certificate management, device provisioning, and firmware signing. Because an insecure IoT device is worse than no device at all.

IoT Architecture and Protocol Comparison. Survey IoT system architectures and compare MQTT, CoAP, and HTTP side by side. Send the same BME280 sensor data over all three protocols and measure bandwidth, latency, and power consumption. Build: Protocol comparison bench on ESP32. Parts: ESP32, BME280 (reuse).

MQTT Broker Setup and Secure Connections. Install and configure Mosquitto with TLS, password authentication, and topic ACLs. Connect to both your self-hosted broker and the SiliconWit.io connected operations platform. Understand retained messages, last will, QoS levels, and persistence. Build: Production-ready Mosquitto broker with TLS. Parts: Raspberry Pi or any Linux machine.

MQTT Clients on ESP32, Pico, and STM32. Write standard MQTT client firmware for three different MCU platforms. Design a consistent topic hierarchy, handle reconnection gracefully, and publish structured JSON payloads with QoS 1. Build: Three-MCU sensor network publishing to one broker. Parts: ESP32, RPi Pico W, STM32 + ESP01 (reuse).

Real-Time Dashboards and Data Visualization. Store MQTT data in InfluxDB via Telegraf, build Grafana dashboards with live charts and gauges, and explore the SiliconWit.io dashboard as a managed alternative. Query historical data and export reports. Build: Grafana dashboard with live sensor data. Parts: No new hardware.

REST APIs, Webhooks, and Device Integration. Design RESTful APIs for device management and data retrieval. Implement webhook endpoints that receive real-time push notifications, validate payloads with HMAC signatures, and integrate with external services. Build: REST API server with webhook receiver. Parts: No new hardware.

Alerts, Automation, and Rule Engines. Configure threshold alerts that notify via email, SMS, Discord, Slack, and Telegram. Build automation flows with Node-RED that trigger actions based on sensor data. Compare self-hosted rule engines with the SiliconWit.io alert system. Build: Multi-channel alert system with automation flows. Parts: No new hardware.

Device Security, TLS, and Provisioning. Generate and deploy X.509 certificates for mutual TLS authentication. Implement device identity and provisioning workflows. Secure firmware updates with signed images. Audit your IoT deployment against common attack vectors. Build: Mutual TLS connection with certificate provisioning. Parts: ESP32 (reuse).

Production IoT Monitoring System. Combine everything from this course into a complete production system. Deploy multiple sensor nodes, a broker with TLS, a time-series database, live dashboards, automated alerts, and cloud forwarding. Handle node failures, broker restarts, and network outages gracefully. Build: Complete production IoT monitoring system. Parts: All reused from prior lessons.