I am interested in having EoN Nodes publish and receive messages through the Eclipse Hono MQTT broker. In reading the documentation it seems that the standard MQTT adapter in Eclipse Hono forces the device to publish to either a 'telemetry' topic or an 'event' topic.
This topics do not work with the standardised Sparkplug topic namespaces defined in the Sparkplug specification.
Does Eclipse Hono work "out-of-the-box" with the Sparkplug topics or would a specific MQTT adapter need to be written?
If a specific adapter needs to be written, is there clear documentation on how to do this?
Thank you.
You are right in assuming that Hono's standard MQTT adapter supports the telemetry and event topics for publishing data only. Consequently, Hono does not work out-of-the-box with the Sparkplug topics. Given that Sparkplug is also an Eclipse standardization effort, it might be worth considering adding native support for Sparkplug to the standard MQTT adapter. Otherwise, implementing a dedicated Sparkplug adapter might be an option as well. There are no detailed instructions for how to implement a protocol adapter. However, the MQTT adapter in particular can serve as a blue print for doing so. It is already split up into a (generic) base class which provides means to forward messages from devices to downstream applications and vice versa. The Kura adapter simply extends this base MQTT adapter class and implements a different Kura-specific topic scheme on top of it. So, in general, this might be a good approach to take for a Sparkplug adapter as well.