76 lines
2.1 KiB
Python
76 lines
2.1 KiB
Python
"""
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LTR-390UV
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Micropython library for the LTR-390UV(ALS+UV)
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=======================================================
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#Preliminary composition 20240120
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@dahanzimin From the Mixly Team
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"""
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import time
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from micropython import const
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_LTR390_ADDRESS = const(0x53)
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_LTR390_REG_CTRL = const(0x00)
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_LTR390_REG_MEAS = const(0x04)
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_LTR390_REG_GAIN = const(0x05)
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_LTR390_REG_ID = const(0x06)
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_LTR390_REG_ALS = const(0x0D)
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_LTR390_REG_UVS = const(0x10)
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_RATE_DEFAULT = const(0x02) #100ms
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_RESOLUTION_20BIT = (0<<4, 4)
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_RESOLUTION_19BIT = (1<<4, 2)
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_RESOLUTION_18BIT = (2<<4, 1)
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_RESOLUTION_17BIT = (3<<4, 0.5)
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_RESOLUTION_16BIT = (4<<4, 0.25)
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_RESOLUTION_13BIT = (5<<4, 0.125)
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_GAIN_X1 = (0, 1)
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_GAIN_X3 = (1, 3)
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_GAIN_X6 = (2, 6)
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_GAIN_X9 = (3, 9)
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_GAIN_X18 = (4, 18)
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class ALS_UVS:
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def __init__(self, i2c_bus, addr=_LTR390_ADDRESS, gain=_GAIN_X1, resolution=_RESOLUTION_17BIT):
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self._device = i2c_bus
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self._address = addr
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self._gain = gain
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self._reso = resolution
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self._flaga = False
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self._flagu = False
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if self._rreg(_LTR390_REG_ID) != 0xB2:
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raise AttributeError("Cannot find a LTR-390UV")
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self._wreg(_LTR390_REG_MEAS, self._reso[0] | _RATE_DEFAULT)
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self._wreg(_LTR390_REG_GAIN, self._gain[0])
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def _wreg(self, reg, val):
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'''Write memory address'''
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self._device.writeto_mem(self._address,reg,val.to_bytes(1, 'little'))
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def _rreg(self, reg, nbytes=1):
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'''Read memory address'''
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return self._device.readfrom_mem(self._address, reg, nbytes)[0] if nbytes<=1 else self._device.readfrom_mem(self._address, reg, nbytes)[0:nbytes]
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def ultraviolet(self):
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if not self._flagu:
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self._wreg(_LTR390_REG_CTRL, 0x0A) #UVS in Active Mode
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time.sleep_ms(int(self._reso[1] * 100))
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self._flagu = True
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self._flaga = False
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buf = self._rreg(_LTR390_REG_UVS, 3)
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return buf[2] << 16 | buf[1] << 8 | buf[0]
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def ambient_light(self):
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if not self._flaga:
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self._wreg(_LTR390_REG_CTRL, 0x02) #ALS in Active Mode
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time.sleep_ms(int(self._reso[1] * 100))
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self._flaga = True
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self._flagu = False
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buf = self._rreg(_LTR390_REG_ALS, 3)
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return 0.6 * (buf[2] << 16 | buf[1] << 8 | buf[0]) / (self._gain[1] * self._reso[1])
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