picopwr

import machine
import time

# --- Pin Definitions ---
# Inputs
power_button = machine.Pin(14, machine.Pin.IN, machine.Pin.PULL_UP)
reset_button = machine.Pin(15, machine.Pin.IN, machine.Pin.PULL_UP)
pc_state_sensor = machine.Pin(22, machine.Pin.IN)

# Outputs
case_led = machine.Pin(16, machine.Pin.OUT)
motherboard_power_control = machine.Pin(12, machine.Pin.OUT)
power_ok_signal = machine.Pin(17, machine.Pin.OUT)
fan_relay_control = machine.Pin(18, machine.Pin.OUT)

# --- Constants ---
POWER_OK_DELAY_MS = 300 # ATX spec: 100-500ms
FAN_COOLDOWN_MINUTES = 5
FAN_COOLDOWN_MS = FAN_COOLDOWN_MINUTES * 60 * 1000
FORCE_SHUTDOWN_HOLD_MS = 5000 # 5 seconds

# --- Initial State ---
motherboard_power_control.high() # Set HIGH to keep active-low relay OFF
power_ok_signal.low()
case_led.low()
fan_relay_control.high() # Set HIGH to keep active-low fan relay OFF
print("Pico controller initialized. Waiting for commands.")

# --- Helper Functions ---
def pulse_motherboard_power():
    """Simulates a short, momentary power button press via the relay."""
    print("Pulsing motherboard power control relay...")
    motherboard_power_control.low()
    time.sleep_ms(500)
    motherboard_power_control.high()

def force_motherboard_power_off():
    """Simulates holding the power button down to force a shutdown."""
    print("FORCING SHUTDOWN: Holding motherboard power control relay ON...")
    motherboard_power_control.low()
    time.sleep(7) # Hold for 7 seconds to ensure force-off
    motherboard_power_control.high()

# --- Main Loop ---
power_press_time = 0
force_shutdown_timer_start = 0
shutdown_fan_timer_start = 0
pc_is_on_flag = pc_state_sensor.value() == 1

while True:
    current_pc_state = pc_state_sensor.value() == 1

    # --- State Change Detection (Handles PWR_OK and Fans) ---
    if current_pc_state and not pc_is_on_flag: # PC just turned ON
        print("PC turned ON.")
        fan_relay_control.low() # Turn fans ON
        shutdown_fan_timer_start = 0
        print(f"Waiting {POWER_OK_DELAY_MS}ms to send PWR_OK...")
        time.sleep_ms(POWER_OK_DELAY_MS)
        power_ok_signal.high()
        print("PWR_OK signal sent.")

    elif not current_pc_state and pc_is_on_flag: # PC just turned OFF
        print("PC turned OFF.")
        power_ok_signal.low()
        print(f"Starting {FAN_COOLDOWN_MINUTES}-minute fan cooldown.")
        shutdown_fan_timer_start = time.ticks_ms()

    pc_is_on_flag = current_pc_state

    # --- Cooldown Timer Logic ---
    if shutdown_fan_timer_start != 0:
        if time.ticks_diff(time.ticks_ms(), shutdown_fan_timer_start) >= FAN_COOLDOWN_MS:
            print("Cooldown complete. Turning fans OFF.")
            fan_relay_control.high()
            shutdown_fan_timer_start = 0

    case_led.value(pc_is_on_flag)

    # --- Button Logic ---
    power_button_pressed = power_button.value() == 0
    reset_button_pressed = reset_button.value() == 0

    if pc_is_on_flag:
        # Forced Shutdown Logic (Only when PC is ON)
        if power_button_pressed and reset_button_pressed:
            if force_shutdown_timer_start == 0:
                force_shutdown_timer_start = time.ticks_ms()
                print("Forced shutdown combo detected. Hold for 5 seconds...")

            if time.ticks_diff(time.ticks_ms(), force_shutdown_timer_start) >= FORCE_SHUTDOWN_HOLD_MS:
                force_motherboard_power_off()
                force_shutdown_timer_start = 0
                time.sleep(5)
        else:
            force_shutdown_timer_start = 0

        # Normal Shutdown Logic
        if power_button_pressed and not reset_button_pressed:
            if power_press_time == 0:
                power_press_time = time.ticks_ms()
        else:
            if power_press_time != 0:
                print("Case power button pressed. Sending clean shutdown signal.")
                pulse_motherboard_power()
                power_press_time = 0

    else: # Power ON Logic (Only when PC is OFF)
        if power_button_pressed:
            if power_press_time == 0:
                power_press_time = time.ticks_ms()
        else:
            if power_press_time != 0:
                print("Case power button pressed. Sending power ON signal.")
                pulse_motherboard_power()
                power_press_time = 0
                time.sleep(3)

    time.sleep_ms(50)