//Method to read the calibration data from the registers
private async Task <BME280_CalibrationData> ReadCoefficeints()
{
// 16 bit calibration data is stored as Little Endian, the helper method will do the byte swap.
CalibrationData = new BME280_CalibrationData();
// Read temperature calibration data
CalibrationData.dig_T1 = ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_T1);
CalibrationData.dig_T2 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_T2);
CalibrationData.dig_T3 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_T3);
// Read presure calibration data
CalibrationData.dig_P1 = ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P1);
CalibrationData.dig_P2 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P2);
CalibrationData.dig_P3 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P3);
CalibrationData.dig_P4 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P4);
CalibrationData.dig_P5 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P5);
CalibrationData.dig_P6 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P6);
CalibrationData.dig_P7 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P7);
CalibrationData.dig_P8 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P8);
CalibrationData.dig_P9 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_P9);
// Read humidity calibration data
CalibrationData.dig_H1 = ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H1);
CalibrationData.dig_H2 = (Int16)ReadUInt16_LittleEndian((byte)eRegisters.BME280_REGISTER_DIG_H2);
CalibrationData.dig_H3 = ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H3);
CalibrationData.dig_H4 = (Int16)((ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H4) << 4) | (ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H4 + 1) & 0xF));
CalibrationData.dig_H5 = (Int16)((ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H5 + 1) << 4) | (ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H5) >> 4));
CalibrationData.dig_H6 = (sbyte)ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H6);
await Task.Delay(1);
return(CalibrationData);
}
private async Task Begin()
{
Debug.WriteLine("BME280::Begin");
byte[] WriteBuffer = new byte[] { (byte)eRegisters.BME280_REGISTER_CHIPID };
byte[] ReadBuffer = new byte[] { 0xFF };
//Read the device signature
Slave.WriteRead(WriteBuffer, ReadBuffer);
Debug.WriteLine("BME280 Signature: " + ReadBuffer[0].ToString());
//Verify the device signature
if (ReadBuffer[0] != BME280_Signature)
{
Debug.WriteLine("BME280::Begin Signature Mismatch.");
return;
}
//Set the initialize variable to true
init = true;
//Read the coefficients table
CalibrationData = await ReadCoefficeints();
//Write control register
await WriteControlRegister();
//Write humidity control register
await WriteControlRegisterHumidity();
}
