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https://github.com/supleed2/ELEC60013-ES-CW1.git
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41 lines
1.5 KiB
Python
41 lines
1.5 KiB
Python
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"""Library for interacting with Si7201 Temperature & Humidity Sensor."""
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import smbus2
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from time import sleep
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class Si7201:
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def __init__(self, i2cBus, i2cAddress=0x40):
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self.i2c = i2cBus
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self.addr = i2cAddress
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i2cBus.pec = True # enable smbus2 Packet Error Checking
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@property
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def temperature(self, decimals=1):
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"""Measured temperature in degrees Celsius, with configurable decimal places, default 1."""
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measure_temp = smbus2.i2c_msg.write(self.addr, [0xF3])
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read_temp = smbus2.i2c_msg.read(self.addr, 2)
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self.i2c.i2c_rdwr(measure_temp)
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sleep(0.1)
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self.i2c.i2c_rdwr(read_temp)
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temp_code = int.from_bytes(read_temp.buf[0] + read_temp.buf[1], "big")
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temp = round(((175.72 * temp_code) / 65536 - 46.85), decimals)
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return temp
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@property
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def humidity(self, decimals=1):
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"""Measured relative humidity in percent, with configurable decimal places, default 1."""
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measure_hum = smbus2.i2c_msg.write(self.addr, [0xF5])
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read_rh = smbus2.i2c_msg.read(self.addr, 2)
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self.i2c.i2c_rdwr(measure_hum)
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sleep(0.1)
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self.i2c.i2c_rdwr(read_rh)
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rh_code = int.from_bytes(read_rh.buf[0] + read_rh.buf[1], "big")
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hum = round((125 * rh_code) / 65536 - 6.0, decimals)
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return hum
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def reset(self):
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"""Reset the sensor."""
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resetcmd = smbus2.i2c_msg.write(self.addr, [0xFE])
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self.i2c.i2c_rdwr(resetcmd)
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