IOT105 · IoT Networking and Protocols (MQTT, HTTP, LoRa)
About Course
Design how IoT devices talk: compare Wi-Fi, BLE, cellular and LoRaWAN, implement HTTP and MQTT messaging with topics, QoS and last-will messages, and encode compact payloads for low-power long-range links.
Who it is for
Learners who can build a working sensor node and now need to connect fleets of devices reliably and efficiently.
Prerequisites
IOT104 (sensors and data collection) and comfort reading short C++ and Python snippets.
What you will be able to do
- Select a connectivity technology for a scenario based on range, power, data rate and cost.
- Implement MQTT publish and subscribe on a simulated ESP32 with a clear topic structure, QoS and last-will messages.
- Compare HTTP request/response and MQTT publish/subscribe and justify which to use.
- Encode and decode a compact binary payload that fits LoRaWAN airtime limits.
Lessons
- Lesson 1 · Connectivity options and trade-offs
- Lesson 2 · HTTP and MQTT in practice
- Lesson 3 · LoRa, LoRaWAN and compact payloads
- Lesson 4 · Lab and assignment
Lab: MQTT telemetry and commands for a cold-room fleet
You connect a simulated ESP32 to a public test MQTT broker, publish JSON telemetry, subscribe to a command topic that changes the reporting interval and configure a last-will message for offline detection. You then write a Python encoder and decoder that packs the same reading into a few bytes for LoRaWAN.
Free tools: Wokwi ESP32 simulator, MQTT Explorer or the HiveMQ web client, Eclipse Mosquitto (local, optional, via Docker Desktop), Google Colab (all free)
Assessed assignment
Submit your Wokwi project, screenshots of the broker client showing telemetry, command and last-will events, and your Colab notebook. Write a one-page connectivity decision for a client with 12 cold rooms in one building and 30 soil sensors on a farm 4 km away: which technology and protocol you choose for each and why. Include your topic naming scheme and explain your QoS choices. Compare the JSON and binary payload sizes and estimate the effect on battery life or airtime.
| Criterion | Weight | What excellent work looks like |
|---|---|---|
| MQTT implementation | 30% | Telemetry, command handling with validation, and retained status with last-will all work and are evidenced. |
| Connectivity decision | 30% | Technology choices for both sites are justified with range, power, data rate and cost, with realistic trade-offs. |
| Protocol design | 20% | Topic scheme is consistent and scalable; QoS and retained flags are chosen deliberately. |
| Payload efficiency | 20% | Binary encoder and decoder are correct and the size comparison is quantified and interpreted. |
Portfolio piece
An MQTT device template with topic conventions and a payload codec, plus a connectivity decision memo you can adapt for real client proposals.
Next step
Continue with IOT106 · Cloud Platforms and Dashboards for IoT · 8 hours · $56.00
Course Content
IOT105 · IoT Networking and Protocols (MQTT, HTTP, LoRa) (8 h)
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Lesson 1 · Connectivity options and trade-offs
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Lesson 2 · HTTP and MQTT in practice
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Lesson 3 · LoRa, LoRaWAN and compact payloads
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Lesson 4 · Lab and assignment
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IOT105 Assessment · IoT Networking and Protocols (MQTT, HTTP, LoRa)