code: func (d *BMP280Driver) Altitude() (alt float32, err error) {
  	atmP, _ := d.Pressure()
  	atmP /= 100.0
  	alt = float32(44330.0 * (1.0 - math.Pow(float64(atmP/bmp280SeaLevelPressure), 0.1903)))
  
  	return
  }
docs: // Altitude returns the current altitude in meters based on the
  // current barometric pressure and estimated pressure at sea level.
  // Calculation is based on code from Adafruit BME280 library
  // 	https://github.com/adafruit/Adafruit_BME280_Library