import glob
import time
import subprocess

# Base directory for the 1-Wire devices for the temperature sensor
base_dir = '/sys/bus/w1/devices/'
# Device folder for the specific sensor
device_folder = glob.glob(base_dir + '28-1f38831e64ff')[0]
# Path to the w1_slave file containing the actual temperature reading
device_file = device_folder + '/w1_slave'

def read_temp_raw():
    """Read the raw temperature data from the sensor."""
    with open(device_file, 'r') as f:
        lines = f.readlines()
    return lines

def read_temp():
    """Parse the raw temperature data and return the temperature in Celsius."""
    lines = read_temp_raw()
    # Keep checking until the sensor says its reading is valid (ends with 'YES')
    while lines[0].strip()[-3:] != 'YES':
        time.sleep(0.2)
        lines = read_temp_raw()
    # Find the temperature value in the second line 't='
    equals_pos = lines[1].find('t=')
    if equals_pos != -1:
        temp_string = lines[1][equals_pos + 2:]
        # The sensor gives temp in thousandths of a degree, so divide by 1000
        temp_c = float(temp_string) / 1000.0
        return temp_c

def execute_command(command):
    """Execute a shell command."""
    subprocess.run(command, shell=True)

# Main loop to read and print the temperature
if __name__ == "__main__":
    # Set up pin 18 to control the fan relay
    execute_command('pinctrl set 18 op')
    while True:
        # Get the current temperature
        temp_c = read_temp()
        print(f"Temperature: {temp_c:.2f} °C")
        
        # Turn fan ON if temperature is 46°C or higher by setting pin to low
        if temp_c >= 46:
            execute_command('pinctrl set 18 dl')
        # Turn fan OFF if temperature drops to 40°C or lower by setting pin to high
        elif temp_c <= 40:
            execute_command('pinctrl set 18  dh')
            
        # Wait 1 second before checking temperature again
        time.sleep(1)