Summary

In this chapter, we explored MQTT and used it to create an MQTT-based IoT alarm module. We introduced the amazing Raspberry Pi Pico W, a microcontroller that complements our Raspberry Pi. We began by understanding MQTT’s publish-subscribe model, which enables efficient and selective communication among connected devices. Additionally, we examined the significance of threading in maximizing the utilization of the Raspberry Pi Pico’s dual-core processor.

We created code for connecting to Wi-Fi and MQTT servers, handling motion detection, and activating alarm components. We learned how to use callback functions to process MQTT messages.

Furthermore, we covered saving and running our code on the Raspberry Pi Pico W, making it a standalone IoT alarm system. We also 3D printed a custom case to house the PIR sensor, LED, buzzer, and Raspberry Pi Pico W.

With our MQTT-based IoT alarm module now complete, we are ready to explore further enhancements as we expand...