55 lines
1.9 KiB
Python
55 lines
1.9 KiB
Python
import glob
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import time
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import subprocess
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# Base directory for the 1-Wire devices for the temperature sensor
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base_dir = '/sys/bus/w1/devices/'
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# Device folder for the specific sensor
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device_folder = glob.glob(base_dir + '28-1f38831e64ff')[0]
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# Path to the w1_slave file containing the actual temperature reading
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device_file = device_folder + '/w1_slave'
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def read_temp_raw():
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"""Read the raw temperature data from the sensor."""
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with open(device_file, 'r') as f:
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lines = f.readlines()
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return lines
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def read_temp():
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"""Parse the raw temperature data and return the temperature in Celsius."""
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lines = read_temp_raw()
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# Keep checking until the sensor says its reading is valid (ends with 'YES')
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while lines[0].strip()[-3:] != 'YES':
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time.sleep(0.2)
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lines = read_temp_raw()
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# Find the temperature value in the second line 't='
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equals_pos = lines[1].find('t=')
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if equals_pos != -1:
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temp_string = lines[1][equals_pos + 2:]
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# The sensor gives temp in thousandths of a degree, so divide by 1000
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temp_c = float(temp_string) / 1000.0
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return temp_c
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def execute_command(command):
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"""Execute a shell command."""
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subprocess.run(command, shell=True)
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# Main loop to read and print the temperature
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if __name__ == "__main__":
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# Set up pin 18 to control the fan relay
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execute_command('pinctrl set 18 op')
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while True:
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# Get the current temperature
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temp_c = read_temp()
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print(f"Temperature: {temp_c:.2f} °C")
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# Turn fan ON if temperature is 46°C or higher by setting pin to low
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if temp_c >= 46:
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execute_command('pinctrl set 18 dl')
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# Turn fan OFF if temperature drops to 40°C or lower by setting pin to high
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elif temp_c <= 40:
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execute_command('pinctrl set 18 dh')
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# Wait 1 second before checking temperature again
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time.sleep(1)
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