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
bme280.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 initalize variable to true
init = true;
//Read the coefficients table
CalibrationData = await ReadCoefficeints();
//Write control register
await WriteControlRegister();
//Write humidity control register
await WriteControlRegisterHumidity();
}
//Method to read the caliberation 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);
CalibrationData.dig_H1 = ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H1_REG);
CalibrationData.dig_H2 = (Int16)((ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H2_MSB) << 8) | ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H2_LSB));
CalibrationData.dig_H3 = ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H3_REG);
CalibrationData.dig_H4 = (Int16)((ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H4_MSB) << 4) | (ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H4_LSB) & 0xF));
CalibrationData.dig_H5 = (Int16)((ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H5_MSB) << 4) | (ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H5_LSB) >> 4));
CalibrationData.dig_H6 = ReadByte((byte)eRegisters.BME280_REGISTER_DIG_H6_REG);
//p_bme280->cal_param.dig_H1 = a_data_u8[BME280_HUMIDITY_CALIB_DIG_H1];
//com_rslt += p_bme280->BME280_BUS_READ_FUNC(
//p_bme280->dev_addr,
//BME280_HUMIDITY_CALIB_DIG_H2_LSB_REG, a_data_u8,
//BME280_HUMIDITY_CALIB_DATA_LENGTH);
//p_bme280->cal_param.dig_H2 = (s16)((((s16)((s8)a_data_u8[BME280_HUMIDITY_CALIB_DIG_H2_MSB])) << BME280_SHIFT_BIT_POSITION_BY_08_BITS) | a_data_u8[BME280_HUMIDITY_CALIB_DIG_H2_LSB]);
//p_bme280->cal_param.dig_H3 = a_data_u8[BME280_HUMIDITY_CALIB_DIG_H3];
//p_bme280->cal_param.dig_H4 = (s16)((( (s16)((s8)a_data_u8[ BME280_HUMIDITY_CALIB_DIG_H4_MSB])) << BME280_SHIFT_BIT_POSITION_BY_04_BITS) |
//(((u8)BME280_MASK_DIG_H4) & a_data_u8[BME280_HUMIDITY_CALIB_DIG_H4_LSB]));
//p_bme280->cal_param.dig_H5 = (s16)((( (s16)((s8)a_data_u8[ BME280_HUMIDITY_CALIB_DIG_H5_MSB])) << BME280_SHIFT_BIT_POSITION_BY_04_BITS) |
//(a_data_u8[BME280_HUMIDITY_CALIB_DIG_H4_LSB] >> BME280_SHIFT_BIT_POSITION_BY_04_BITS));
//p_bme280->cal_param.dig_H6 = (s8)a_data_u8[BME280_HUMIDITY_CALIB_DIG_H6];
await Task.Delay(1);
return(CalibrationData);
}
