We are working on a new project called OpenCN-Companion which is aimed at providing a development and test framework with a Raspberry Pi 4 and a EtherCAT slave HAT plugged on it.
We will use the EtherCAT® Shield for Raspberry PI – EtherBerry which provides various access to GPIOs. Please let us know if you have some experience with this kind of extension.
In this context, the EtherCAT command line tool (available at the official IgH EtherCAT site will be ported.