Hi All,

I'm looking to develop an ESP32-based local (that is the hub is on the same network) and small (usually no more than 10 devices per hub) IoT network over wifi.

For Most of the runtime, the devices report readings with max 1s frequency to the hub, and MQTT is great for this. But I'm looking for future needs such as FOTA, and maybe some RPC on the devices. MQTT can be used to execute functions (with the result reported on another topic) on the edge devices but it feels hacky and wrong long term.

I've looked at various IoT frameworks, but many are paid which is a non-starter or seems like overkill (like a cloud backend for millions of devices). I'm looking for the best tools for a small device network, running on a local resource-constrained Linux.

I'm hoping for open-ended feedback or some library recommendations for further reading, Many thanks in advance!