69 lines
1.6 KiB
Python
69 lines
1.6 KiB
Python
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# Imports
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import onewire, ds18x20, time
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from machine import Pin, PWM
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# Set up the LED pins
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red = Pin(18, Pin.OUT)
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amber = Pin(19, Pin.OUT)
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green = Pin(20, Pin.OUT)
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# Set up the Buzzer pin as PWM
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buzzer = PWM(Pin(13))
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# Start PWM duty to 0% at program start
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buzzer.duty_u16(0)
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# Set the data pin for the sensor
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SensorPin = Pin(26, Pin.IN)
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# Tell MicroPython that we're using a DS18B20 sensor, and which pin it's on
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sensor = ds18x20.DS18X20(onewire.OneWire(SensorPin))
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# Look for DS18B20 sensors (each contains a unique rom code)
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roms = sensor.scan()
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def alarm(): # Our alarm function
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buzzer.duty_u16(10000) # Buzzer duty (volume) up
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for i in range(5): # Run this 5 times
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buzzer.freq(5000) # Higher pitch
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# LEDs ON
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red.value(1)
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amber.value(1)
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green.value(1)
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time.sleep(0.2) # wait 1 second
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buzzer.freq(1000) # Lower pitch
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# LEDs OFF
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red.value(0)
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amber.value(0)
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green.value(0)
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time.sleep(0.2) # wait 1 second
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buzzer.duty_u16(0) # Buzzer duty (volume) off
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while True: # Run forever
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time.sleep(5) # Wait 5 seconds between readings
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for rom in roms: # For each sensor found (just 1 in our case)
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sensor.convert_temp() # Convert the sensor units to centigrade
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time.sleep(1) # Always wait 1 second after converting
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reading = sensor.read_temp(rom) # Take a temperature reading
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print(reading) # Print the reading
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if reading < 25: # If reading is less than or equal to 18
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alarm() # Call our alarm function
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