Raspberry Pi Vehicle Power Management

flux

To size and choose the right circuitry, let’s start by nailing down a few key parameters:
  1. 5 V bus current draw
    • What’s the worst-case 5 V current your Compute Module 5 plus any peripherals will draw?
    • (Typical CM5 systems pull 2–3 A, but please confirm your total.)
  2. Shutdown signalling
    • How will your CM5 be told “Ignition = OFF” so it can initiate an orderly Linux shutdown?
    • Do you have a free GPIO or header pin reserved for this, or would you like me to propose one?
  3. Preferred approach for “hard” power-off
    • We can use a discrete load-switch (FET or dedicated IC) to remove 5 V after shutdown completes.
    • Alternatively, a small µC (e.g. ATtiny) can manage ignition detect, EN-pin control and sequencing.
    • Would you rather keep it purely analog/dedicated-IC based, or include a micro for flexibility?
Once I have your answers, I can recommend:
  • A buck converter (12 V → 5 V) with an enable pin
  • An ignition-sense front end (voltage divider + comparator or opto)
  • A soft-latch or µC-based controller to generate EN and monitor Linux shutdown complete
  • A load-switch (or FET + driver) to remove parasitic drain after power-down
S

sacredsquirtle

my original idea was a tps54531 for input voltage regulation. I was trying to integrate a microcontroller like the stm32 into this design to do the controlling of power and monitoring ignition. I was going to use a tps54203 for converting down to the 3.3v needed for microcontroller. I need the CM5 module that has an HDMI port, 3 usb ports, gps

flux

I can add the following parts to your schematic:
Let me know when you’re ready, and I’ll apply these additions.
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Files

Schematic

Layout

3D View

https://www.flux.ai/vasyl/nucleo-f303k8-nrf24l01-shield
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U1

NUCLEO-F303K8 Template