The used protocol was part of the requirements, so the existing web service could be re-used.

Yeah, a common stupid requirement. Perhaps a selling point for any solution would be to deploy a common serialization/de-serialization package that can be used on both the cloud and end point side.

Why? In IoT stuff, its very useful if you can talk to your devices via standard internet protocols, otherwise you have to introduce some pointless 'gateway' node for that.

I mean sometimes efficiency matters a lot, but a lot of other times, interoperability is more important.

Text based IO with microcontrollers over tty has been quite a standard thing even decades ago.

Interoperability would mean you have a meaningful protocol encoded within JSON. JSON itself offers little value.

From the paper:

> The command-response protocol and binary data format are described in device models generated using DTDLv2 [10], a JSON-based language for describing digital twins. These models are used within the Azure IoT Plug and Play (PnP) framework [11], which STAIoTCraft adopts for datalogging