33 lines
1.0 KiB
Python
33 lines
1.0 KiB
Python
#!/usr/bin/python
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from Adafruit_MAX31855 import MAX31855
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class MAX31855SPI(object):
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'''Python driver for [MAX38155 Cold-Junction Compensated Thermocouple-to-Digital Converter](http://www.maximintegrated.com/datasheet/index.mvp/id/7273)
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Requires:
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- adafruit's MAX31855 SPI-only device library
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'''
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def __init__(self, spi_dev):
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self.max31855 = MAX31855.MAX31855(spi=spi_dev)
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def get(self):
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'''Reads SPI bus and returns current value of thermocouple.'''
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state = self.max31855.readState()
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if state['openCircuit']:
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raise MAX31855Error('Not Connected')
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elif state['shortGND']:
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raise MAX31855Error('Short to Ground')
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elif state['shortVCC']:
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raise MAX31855Error('Short to VCC')
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elif state['fault']:
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raise MAX31855Error('Unknown Error')
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return self.max31855.readLinearizedTempC()
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class MAX31855SPIError(Exception):
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def __init__(self, value):
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self.value = value
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def __str__(self):
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return repr(self.value)
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