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Kenneth Bell
70 lines
1.7 KiB
Go
70 lines
1.7 KiB
Go
package bme280
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// Constants/addresses used for I2C.
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// The I2C address which this device listens to.
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const Address = 0x76
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// Registers. Names, addresses and comments copied from the datasheet.
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const (
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CTRL_MEAS_ADDR = 0xF4
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CTRL_HUMIDITY_ADDR = 0xF2
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CTRL_CONFIG = 0xF5
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REG_PRESSURE = 0xF7
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REG_CALIBRATION = 0x88
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REG_CALIBRATION_H1 = 0xA1
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REG_CALIBRATION_H2LSB = 0xE1
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CMD_RESET = 0xE0
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WHO_AM_I = 0xD0
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CHIP_ID = 0x60
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)
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// Increasing sampling rate increases precision but also the wait time for measurements. The datasheet has a table of
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// suggested values for oversampling, output data rates, and iir filter coefficients by use case.
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const (
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SamplingOff Oversampling = iota
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Sampling1X
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Sampling2X
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Sampling4X
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Sampling8X
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Sampling16X
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)
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// In normal mode (the default) the sensor takes masurements periodically. In forced
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// mode, the sensor takes a measurement only when requested.
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//
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// For use-cases with infrequent sampling, forced mode is more power efficient.
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const (
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ModeNormal Mode = 0x03
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ModeForced Mode = 0x01
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ModeSleep Mode = 0x00
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)
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// IIR filter coefficients, higher values means steadier measurements but slower reaction times
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const (
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Coeff0 FilterCoefficient = iota
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Coeff2
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Coeff4
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Coeff8
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Coeff16
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)
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// Period of standby in normal mode which controls how often measurements are taken
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//
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// Note Period10ms and Period20ms are out of sequence, but are per the datasheet
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const (
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Period0_5ms Period = 0b000
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Period62_5ms = 0b001
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Period125ms = 0b010
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Period250ms = 0b011
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Period500ms = 0b100
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Period1000ms = 0b101
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Period10ms = 0b110
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Period20ms = 0b111
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)
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const (
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SEALEVEL_PRESSURE float32 = 1013.25 // in hPa
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)
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