Heimdall

The SmartLight Streetlight Control Node, known internally as Heimdall, is a compact, low-power device that transforms conventional street lighting into an intelligent traffic-monitoring network. Heimdall runs a custom TinyML model capable of detecting, localising and counting vehicles in real time while consuming only 1.2 W of power. The node integrates bespoke printed-circuit boards and a miniature processor no larger than a £2 coin, yet it delivers detection performance that rivals larger systems. Raw data feeds into SmartLight’s cloud-hosted content management system (CMS) via MQTT, enabling visualisations, statistics and real-time alerts. Field trials across the UK demonstrated robust operation when mounted on streetlights. Heimdall exemplifies SmartLight’s design philosophy: use bespoke hardware and optimised AI algorithms to achieve efficient edge processing. Its 1.2 W draw means the node can be powered via a streetlamp’s existing supply without additional cabling. The on-device model runs within a memory footprint of 14 KB and has been benchmarked at over 95 % classification accuracy in controlled tests. Integration with a custom CMS allows data from multiple nodes to be aggregated, analysed and exported to municipal dashboards. This end-to-end stack demonstrates the viability of edge AI for smart infrastructure — the system does not rely on continuous uplinks for inference, but it can stream results when connectivity is available, balancing local autonomy with central oversight. In sum, Heimdall provides a scalable, plug-and-play solution for cities seeking to improve traffic flow, safety and energy efficiency.