41 lines
909 B
Python
41 lines
909 B
Python
import sys
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from i2cdriver import I2CDriver, EDS
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# Using a TCA9548A Low-Voltage 8-Channel I2C Switch
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# Three LM75B temperature sensors are connected to
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# channels 0,1 and 2. All are at address 0x48.
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class Mux:
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def __init__(self, i2, a = 0x70):
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self.i2 = i2
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self.a = a
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def select(self, n):
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assert n in range(8)
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self.i2.start(self.a, 0)
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self.i2.write([1 << n])
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self.i2.stop()
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if __name__ == '__main__':
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i2 = I2CDriver(sys.argv[1])
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mux = Mux(i2)
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sensors = [
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(0, EDS.Temp(i2)),
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(1, EDS.Temp(i2)),
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(2, EDS.Temp(i2))
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]
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# Reset all 8 channels
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for chan in range(8):
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mux.select(chan)
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i2.reset()
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def read(chan, dev):
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mux.select(chan)
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celsius = dev.read()
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return celsius
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while 1:
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print(" ".join(["%.1f" % read(chan, dev) for chan,dev in sensors]))
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