I started this project as a free-time project to integrate the Logitech Z906 sound system into my smart home, and to be able to stream music using Spotify Connect and other sources. In order to have full control over the system, I desoldered the microcontroller from the control panel's circuit and solder wired the LEDs and input buttons to a Raspberry Pi Zero W. I hooked up the required wires of the subwoofer cable and implemented a small python service, that accepts commands from various sources (panel, IR, HTTP) and forwards them to the subwoofer.
Install using:
curl -sL https://raw.githubusercontent.com/dominikberse/logitech-z906/master/install.sh | sh
TODO
If your Raspberry Pi has a wireless chip, bluetooth UART must be reconfigured to use the mini-UART. Otherwise the required baudrate and odd parity are not available (tested for Raspberry Pi Zero W). This line is added to /boot/config.txt under [all] section by the installation script (at the bottom).
dtoverlay=pi3-miniuart-bt