This project was started from this discussion. (Mikrocontroller.net)

The Hoymiles protocol was decrypted through the voluntary efforts of many participants. Ahoy, among others, was developed based on this work. The project is licensed under an Open Source License (GNU General Public License version 2).

The software was developed to the best of our knowledge and belief. Nevertheless, no liability can be accepted for a malfunction or guarantee loss of the inverter.

OpenDTU is freely available. If you paid money for the software, you probably got ripped off.