Martin Harizanov blogged about his cheap DIY IoT smoke detector:
This project is an upgrade to a previous project of mine – the DIY IoT smoke alarm. It is a more advanced version that uses dedicated hardware rather than the generic “Funky” project + external components. In essence, the module integrates into cheap smoke detectors and provides wireless event transmission plus periodic battery measurements to cloud infrastructure using BBoilRF as a gateway (over MQTT).
Check out the video after the break.