hudiy.eu

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ignition = DigitalInputDevice(IGN_PIN, pull_up=None, active_state=True)

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ignition = DigitalInputDevice(IGN_PIN, pull_up=False, active_state=True)

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ignition = DigitalInputDevice(IGN_PIN, pull_up=False)

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#!/usr/bin/env python3
"""
CarPi Power Management (IGN monitoring only)
- Uses hardware for actual power shutdown
- Logs major state transitions for diagnostics
"""

import lgpio, time, os, signal, sys
import logging

# --- Logging Setup ---
logging.basicConfig(
    filename="/var/log/carpi.log",
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
)
logging.info("CarPi power manager started")

# --- Configuration ---
IGN_PIN = 12       # BCM12 - ignition sense
IGN_LOW_TIME = 10  # seconds ignition must stay low before shutdown
POLL_INTERVAL = 0.1

# --- Setup GPIO ---
h = lgpio.gpiochip_open(0)
lgpio.gpio_claim_input(h, IGN_PIN)

shutdown_initiated = False
timer = 0.0

# --- Cleanup handler ---
def exit_handler(*_):
    logging.info("CarPi power manager exiting")
    try:
        lgpio.gpiochip_close(h)
    except:
        pass
    sys.exit(0)

signal.signal(signal.SIGINT, exit_handler)
signal.signal(signal.SIGTERM, exit_handler)

# --- Main loop ---
try:
    while True:
        ign = lgpio.gpio_read(h, IGN_PIN)

        if ign == 1:
            # Ignition ON
            if timer > 0:
                logging.info("IGN high → reset shutdown timer")
            timer = 0.0

        else:
            # Ignition OFF
            if timer == 0:
                logging.info("IGN dropped → countdown started")
            timer += POLL_INTERVAL

            if timer >= IGN_LOW_TIME and not shutdown_initiated:
                shutdown_initiated = True
                logging.info(
                    f"Shutdown triggered after {timer:.1f}s of IGN low (hardware will cut power)"
                )
                os.system("sudo shutdown -h now")
                break

        time.sleep(POLL_INTERVAL)

except KeyboardInterrupt:
    exit_handler()

finally:
    exit_handler()

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[Unit]
Description=CarPi Power Management for Raspberry Pi
After=multi-user.target
Before=shutdown.target halt.target reboot.target

[Service]
Type=simple
ExecStart=/usr/bin/python3 /usr/local/bin/carpi.py

# Only restart if crash — NOT when intentional CAN sleep or shutdown delay
Restart=on-failure
RestartSec=3

User=root
Environment=PYTHONUNBUFFERED=1
StandardOutput=journal
StandardError=journal

# Allow script to cleanly release GPIO latch before shutdown
ExecStop=/usr/bin/pkill -f carpi.py
KillSignal=SIGINT
TimeoutStopSec=10

[Install]
WantedBy=multi-user.target

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sudo system enable carpi.service
sudo system start carpi.service

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# CANBUS
dtoverlay=mcp2515-can0,oscillator=8000000,interrupt=23,spimaxfrequency=1000000

# CarPi
dtoverlay=gpio-poweroff,gpiopin=25,active_low
#dtoverlay=hifiberry-dacplus-std