public Bme280 Initialize()
{
Logger.Log("BME280::Initialize");
try
{
var settings = new I2cConnectionSettings(Bme280Address);
settings.BusSpeed = I2cBusSpeed.StandardMode;
settings.SharingMode = I2cSharingMode.Shared;
string aqs = I2cDevice.GetDeviceSelector(_i2CControllerName);
_bme280 = I2cDevice.FromId(_i2CControllerName, settings);
if (_bme280 == null)
{
Logger.Log("BME280 device not found", Logger.LogLevel.Warning);
}
}
catch (Exception e)
{
Logger.Log("BME 280 exception: " + e.Message + "\n" + e.StackTrace, Logger.LogLevel.Error);
throw;
}
byte[] readChipId = new byte[] { (byte)ERegisters.BME280_REGISTER_CHIPID };
byte[] readBuffer = new byte[] { 0xFF };
//Read the device signature
_bme280.WriteReadPartial(readChipId, readBuffer);
Logger.Log("BME280 Signature: " + readBuffer[0], Logger.LogLevel.Info);
//Verify the device signature
if (readBuffer[0] != Bme280Signature)
{
Logger.Log("BME280::Begin Signature Mismatch.", Logger.LogLevel.Warning);
return(this);
}
//Set configuration registers
WriteConfigRegister();
WriteControlMeasurementRegister();
WriteControlRegisterHumidity();
//Set configuration registers again to ensure configuration of humidity
WriteConfigRegister();
WriteControlMeasurementRegister();
WriteControlRegisterHumidity();
//Read the coefficients table
_calibrationData = ReadCoefficeints();
//Dummy read temp to setup t_fine
ReadTemperature();
return(this);
}
//Method to read the caliberation data from the registers
private Bme280CalibrationData ReadCoefficeints()
{
// 16 bit calibration data is stored as Little Endian, the helper method will do the byte swap.
_calibrationData = new Bme280CalibrationData();
// Read temperature calibration data
_calibrationData.DigT1 = (ushort)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_T1, 2);
_calibrationData.DigT2 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_T2, 2);
_calibrationData.DigT3 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_T3, 2);
// Read presure calibration data
_calibrationData.DigP9 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P9, 2);
_calibrationData.DigP8 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P8, 2);
_calibrationData.DigP7 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P7, 2);
_calibrationData.DigP6 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P6, 2);
_calibrationData.DigP5 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P5, 2);
_calibrationData.DigP4 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P4, 2);
_calibrationData.DigP3 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P3, 2);
_calibrationData.DigP2 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P2, 2);
_calibrationData.DigP1 = (ushort)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_P1, 2);
// Read humidity calibration data
_calibrationData.DigH1 = (byte)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_H1);
_calibrationData.DigH2 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_H2, 2);
_calibrationData.DigH3 = (byte)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_H3);
short e4 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_H4_L); // Read 0xE4
short e5 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_H4_H); // Read 0xE5
short e6 = (short)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_H5_H); // Read 0xE6
_calibrationData.DigH6 = (sbyte)_bme280.ReadValue((byte)ERegisters.BME280_REGISTER_DIG_H6);
_calibrationData.DigH4 = (short)((e4 << 4) + (e5 & 0x0F));
_calibrationData.DigH5 = (short)((e5 >> 4) + (e6 << 4));
return(_calibrationData);
}
