I wanted to let you know that we have just released under Apache 2 a peer-to-peer implementation of our zenoh protocol called Zeno-He (Zenoh Helium). This implementation fits in about 1KByte of RAM and has 4 bytes wire overhead. This implementation not only is incredibly resource efficient but it is also blazing fast as it delivers incredible point-to-point throughput and low latency.
We will be releasing a brokering system by the end of the year, likewise we be glad to help-out integrating zenoh as one of the protocols supported by ROS2. This could allow to bring ROS2 on micro-controllers!
N.B. For those of you that are familiar with XRCE, zenoh is the protocol we are proposing for standardisation. But as the standard is not finalised yet, we will keep referring it as zenoh.