MODBUS master and slave?
Is there any MODBUS implementation for the Propeller so far? I've used the search engine but haven't found much. MODBUS is used for industrial IO modules and VFDs, usually with rather low baud rates like 9.6kBd. But as the P2 has lots of power so I think it could even be used for transmitting servo commands with higher baud rates like 1MBd.
Unlike other standards like EtherCAT I think it's relatively easy to implement, at least if not all commands need to be supported. Simple register read and write commands are all you need for simple IO modules and even VFDs or servo drives with hundreds of parameters can be controlled that way.
BTW. I find the documentation of how MODBUS communication works in the technical manual of the Yaskawa GA500 drives much more comprehensible than the original MODBUS specification. It is relatively straigh-forward and explains the basics on only 6 pages whereas the official docs have 50 pages and are written in a quite "academical" style.
However, getting the CRC calculation, error and timeout handling right is somehow non-trivial, I think. So if there is existing code it would help me a lot.