Automotive Pi Interface PCB

I need a single PCB that will sit inside a running vehicle, accept the raw 12 V battery line, regulate it cleanly to the 5 V rail required by a Raspberry Pi 5, and report back four live signals: actual battery voltage, battery load current, tachometer pulses, and oil-sender pressure (via an ADS1115 already on the Pi side).

Key electrical functions
• Buck or synchronous step-down from 12 V to a rock-solid 5 V at the Pi’s expected current draw, with noise low enough not to disturb the Pi’s camera or Wi-Fi.
• High-side voltage divider and current-sense shunt so the Pi can read battery voltage and current on separate ADC channels (ADS1115).
• An optocoupler on the tachometer line so the noisy ignition pulses never reach the Pi directly—only clean logic-level edges do.
• A routed trace that passes the oil-sender wire through a precision resistor into the ADS1115 input; the resistor must be mounted on the PCB so calibration stays fixed.

Mechanical and I/O
• A full 40-pin right-angle header soldered on-board so the Pi plugs straight in—no ribbon cables.
• Screw or JST terminals for the 12 V feed, tachometer, oil sender, and any sense leads.
• Four mounting holes; spacing is your call, as board outline is still flexible.

Deliverables
1. Schematic with all parts labelled and footprints assigned.
2. PCB layout (KiCad preferred, but Altium is acceptable) with manufacturing notes.
3. BOM with distributor part numbers.
4. Gerber and drill files ready for a standard two-layer fabrication run.

I will flash test the board on a bench supply and then in-car; acceptance is clean 5 V output under cranking transients and accurate ADC readings that track a multimeter.