Opel-CAN-BT

Project that is supposed to be bridge between mobile phone and car (Opel Zafira B, Vectra C, Astra H etc) for purposes of listening to music.
Idea is to connect it to AUX-IN, one of the CAN buses, and to mobile phone via Bluetooth, play music, show song info on main display.
Device shall put itself to sleep when entertainment unit is shutting down and wake up with it. For this purpose ESP32 and audio DAC are powered by separate DC-DC converter that can be disabled by STM. STM is powered by low quiescent current LDO so it can sleep separately and await CAN BUS activity.