I am new to this community and a great fan of all knowledge and ideas out here!
Lately I have been working on a custom Volumio audio streamer to match my Advance Acoustic setup. The base of this build was a Rpi4b and the nice Allo DigiOne Signature board. Since the power supply for the DigiOne Signature is a critical part, this was separated from the Rpi supply. A dual 5V power supply solution feeds the both.
The startup/shutdown electronics and external displays have a 3th separate 5V power supply. It took a bit to find a touch screen that made a nice fit in the front of the Advance Acoustic FM tuner casing. In the end a 7” 1280x480 from AliExpress was used.
Both side displays are 2.8” 320x240 types.
Many thanks to @Gelo5! His Advance acoustic skin was used as a template and modified.
These power supply boards take a while before the super capacitors are fully charged. 2 of the relays are delays to delay the connection of the both power supplies with the RPi and card. The other one is to delay the startup of the side displays on the 3th supply. The 4th one is a toggle relay (flipflop) for power up/down of the entire unit.
Using the FM-tuner housing, limits the possibilities a bit. A larger touchscreen would have been nicer and more practical in use. For this, the power button had to be scrapped and the unity with the other Advance Acoustic elements was less. At the end I decided for this 7" touchscreen.
At the moment the power supply for the RPi4 takes a long time to get sufficient reserves (charging super capacitors) to start the RPi and touchscreen. I am working on a redesign of this power supply.
Otherwise the streamer works excellent and sounds great!
