kopia lustrzana https://github.com/cyoung/stratux
82 wiersze
2.0 KiB
Go
82 wiersze
2.0 KiB
Go
// Package sensors provides a stratux interface to sensors used for AHRS calculations.
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package sensors
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import (
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"errors"
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"time"
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"../goflying/bmp280"
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"github.com/kidoman/embd"
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)
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const (
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bmp280PowerMode = bmp280.NormalMode
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bmp280Standby = bmp280.StandbyTime63ms
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bmp280FilterCoeff = bmp280.FilterCoeff16
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bmp280TempRes = bmp280.Oversamp16x
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bmp280PressRes = bmp280.Oversamp16x
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)
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// BMP280 represents a BMP280 sensor and implements the PressureSensor interface.
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type BMP280 struct {
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sensor *bmp280.BMP280
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data *bmp280.BMPData
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running bool
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}
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var errBMP = errors.New("BMP280 Error: BMP280 is not running")
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// NewBMP280 looks for a BMP280 connected on the I2C bus having one of the valid addresses and begins reading it.
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func NewBMP280(i2cbus *embd.I2CBus, freq time.Duration) (*BMP280, error) {
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var (
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bmp *bmp280.BMP280
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errbmp error
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)
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bmp, errbmp = bmp280.NewBMP280(i2cbus, bmp280.Address1,
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bmp280PowerMode, bmp280Standby, bmp280FilterCoeff, bmp280TempRes, bmp280PressRes)
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if errbmp != nil { // Maybe the BMP280 isn't at Address1, try Address2
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bmp, errbmp = bmp280.NewBMP280(i2cbus, bmp280.Address2,
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bmp280PowerMode, bmp280Standby, bmp280FilterCoeff, bmp280TempRes, bmp280PressRes)
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}
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if errbmp != nil {
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return nil, errbmp
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}
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newbmp := BMP280{sensor: bmp, data: new(bmp280.BMPData)}
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go newbmp.run()
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return &newbmp, nil
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}
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func (bmp *BMP280) run() {
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bmp.running = true
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clock := time.NewTicker(100 * time.Millisecond)
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for bmp.running {
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<-clock.C
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bmp.data = <-bmp.sensor.C
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}
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}
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// Temperature returns the current temperature in degrees C measured by the BMP280
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func (bmp *BMP280) Temperature() (float64, error) {
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if !bmp.running {
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return 0, errBMP
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}
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return bmp.data.Temperature, nil
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}
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// Pressure returns the current pressure in mbar measured by the BMP280
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func (bmp *BMP280) Pressure() (float64, error) {
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if !bmp.running {
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return 0, errBMP
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}
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return bmp.data.Pressure, nil
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}
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// Close stops the measurements of the BMP280
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func (bmp *BMP280) Close() {
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bmp.running = false
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bmp.sensor.Close()
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}
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