07-06-2020, 02:58 AM
Hello All, I have a Raspberry Pi 4 B wired into a 12v to 5v 3A DC to DC connector, this connector is wired directly into the same wiring harness that the amp is. My amp that I have is wired directly to the wring harness that leads to 12v battery ground.
With the raspberry pi disconnected from the amp and the 3.5mm connected to my phone, the ground loop whine is gone, but when it is, I notice the classic signs, alternator whine, and changing with engine RPM's. I've tried wiring it to the 12v cigarette adapter with no luck, I've tried grounding both the amp and the Pi in the same spot on a chassis grounding bolt with no luck.
I did notice however that when using the GIPO ground pin in the number 9 slot, it reduced the whine a tad when grounded.
Is there something I'm missing? I don't understand where there could be a ground potential difference and as to why the Pi isn't fully cooperating. Any advice is welcome!
P.S. if someone could tell me whether or not the Pi can accept SWC controls over its 3.5mm jack and how to decode them, that would be fantastic as the SWC module I have has a 3.5mm output.
With the raspberry pi disconnected from the amp and the 3.5mm connected to my phone, the ground loop whine is gone, but when it is, I notice the classic signs, alternator whine, and changing with engine RPM's. I've tried wiring it to the 12v cigarette adapter with no luck, I've tried grounding both the amp and the Pi in the same spot on a chassis grounding bolt with no luck.
I did notice however that when using the GIPO ground pin in the number 9 slot, it reduced the whine a tad when grounded.
Is there something I'm missing? I don't understand where there could be a ground potential difference and as to why the Pi isn't fully cooperating. Any advice is welcome!
P.S. if someone could tell me whether or not the Pi can accept SWC controls over its 3.5mm jack and how to decode them, that would be fantastic as the SWC module I have has a 3.5mm output.