/// <summary>
/// Reads the compensation data.
/// </summary>
/// <remarks>
/// The compensation data is written to the chip at the time of manufacture and cannot be changed.
/// This information is used to convert the readings from the sensor into actual temperature,
/// pressure and humidity readings.
/// From the data sheet, the register addresses and length are:
/// Temperature and pressure: start address 0x88, end address 0x9F (length = 24)
/// Humidity 1: 0xa1, length = 1
/// Humidity 2 and 3: start address 0xe1, end address 0xe7, (length = 8)
/// </remarks>
private void ReadCompensationData()
{
var temperatureAndPressureData = _bme280.ReadRegisters(0x88, 24);
var humidityData1 = _bme280.ReadRegisters(0xa1, 1);
var humidityData2To6 = _bme280.ReadRegisters(0xe1, 7);
_compensationData.T1 = (ushort)(temperatureAndPressureData[0] + (temperatureAndPressureData[1] << 8));
_compensationData.T2 = (short)(temperatureAndPressureData[2] + (temperatureAndPressureData[3] << 8));
_compensationData.T3 = (short)(temperatureAndPressureData[4] + (temperatureAndPressureData[5] << 8));
//
_compensationData.P1 = (ushort)(temperatureAndPressureData[6] + (temperatureAndPressureData[7] << 8));
_compensationData.P2 = (short)(temperatureAndPressureData[8] + (temperatureAndPressureData[9] << 8));
_compensationData.P3 = (short)(temperatureAndPressureData[10] + (temperatureAndPressureData[11] << 8));
_compensationData.P4 = (short)(temperatureAndPressureData[12] + (temperatureAndPressureData[13] << 8));
_compensationData.P5 = (short)(temperatureAndPressureData[14] + (temperatureAndPressureData[15] << 8));
_compensationData.P6 = (short)(temperatureAndPressureData[16] + (temperatureAndPressureData[17] << 8));
_compensationData.P7 = (short)(temperatureAndPressureData[18] + (temperatureAndPressureData[19] << 8));
_compensationData.P8 = (short)(temperatureAndPressureData[20] + (temperatureAndPressureData[21] << 8));
_compensationData.P9 = (short)(temperatureAndPressureData[22] + (temperatureAndPressureData[23] << 8));
//
_compensationData.H1 = humidityData1[0];
_compensationData.H2 = (short)(humidityData2To6[0] + (humidityData2To6[1] << 8));
_compensationData.H3 = humidityData2To6[2];
_compensationData.H4 = (short)((humidityData2To6[3] << 4) + (humidityData2To6[4] & 0xf));
_compensationData.H5 = (short)(((humidityData2To6[4] & 0xf) >> 4) + (humidityData2To6[5] << 4));
_compensationData.H6 = (sbyte)humidityData2To6[6];
}
/// <summary>
/// Create a new TMP102 object using the default configuration for the sensor.
/// </summary>
/// <param name="address">I2C address of the sensor.</param>
/// <param name="speed">Speed of the communication with the sensor.</param>
public TMP102(byte address = 0x48, ushort speed = 100, ushort updateInterval = MinimumPollingPeriod,
float temperatureChangeNotificationThreshold = 0.001F)
{
if ((speed < 10) || (speed > 1000))
{
throw new ArgumentOutOfRangeException(nameof(speed), "Speed should be 10 KHz to 3,400 KHz.");
}
if (temperatureChangeNotificationThreshold < 0)
{
throw new ArgumentOutOfRangeException(nameof(temperatureChangeNotificationThreshold), "Temperature threshold should be >= 0");
}
if ((updateInterval != 0) && (updateInterval < MinimumPollingPeriod))
{
throw new ArgumentOutOfRangeException(nameof(updateInterval), "Update period should be 0 or >= than " + MinimumPollingPeriod);
}
TemperatureChangeNotificationThreshold = temperatureChangeNotificationThreshold;
_updateInterval = updateInterval;
_tmp102 = new I2CBus(address, speed);
var configuration = _tmp102.ReadRegisters(0x01, 2);
_sensorResolution = (configuration[1] & 0x10) > 0
? Resolution.Resolution13Bits
: Resolution.Resolution12Bits;
if (updateInterval > 0)
{
StartUpdating();
}
else
{
Update();
}
}
/// <summary>
/// Update the temperature and pressure from the sensor and set the Pressure property.
/// </summary>
public void Update()
{
//
// Tell the sensor to take a temperature and pressure reading, wait for
// 3ms (see section 2.2 of the datasheet) and then read the ADC values.
//
_mpl115a2.WriteBytes(new byte[] { Registers.StartConversion, 0x00 });
Thread.Sleep(5);
var data = _mpl115a2.ReadRegisters(Registers.PressureMSB, 4);
//
// Extract the sensor data, note that this is a 10-bit reading so move
// the data right 6 bits (see section 3.1 of the datasheet).
//
var pressure = (ushort)(((data[0] << 8) + data[1]) >> 6);
var temperature = (ushort)(((data[2] << 8) + data[3]) >> 6);
Temperature = (float)((temperature - 498.0) / -5.35) + 25;
//
// Now use the calculations in section 3.2 to determine the
// current pressure reading.
//
const double PRESSURE_CONSTANT = 65.0 / 1023.0;
var compensatedPressure = _coefficients.A0 + ((_coefficients.B1 + (_coefficients.C12 * temperature))
* pressure) + (_coefficients.B2 * temperature);
Pressure = (float)(PRESSURE_CONSTANT * compensatedPressure) + 50;
}
/// <summary>
/// Read the six sensor bytes and set the values for the X, Y and Z acceleration.
/// </summary>
/// <remarks>
/// All six acceleration registers should be read at the same time to ensure consistency
/// of the measurements.
/// </remarks>
public void Update()
{
var data = _adxl345.ReadRegisters(Registers.X0, 6);
X = (short)(data[0] + (data[1] << 8));
Y = (short)(data[2] + (data[3] << 8));
Z = (short)(data[4] + (data[5] << 8));
if ((_updateInterval != 0) &&
((Math.Abs(X - _lastX) > AccelerationChangeNotificationThreshold) ||
(Math.Abs(Y - _lastY) > AccelerationChangeNotificationThreshold) ||
(Math.Abs(Z - _lastZ) > AccelerationChangeNotificationThreshold)))
{
Vector lastNotifiedReading = new Vector(_lastX, _lastY, _lastZ);
Vector currentReading = new Vector(X, Y, Z);
_lastX = X;
_lastY = Y;
_lastZ = Z;
AccelerationChanged(this, new SensorVectorEventArgs(lastNotifiedReading, currentReading));
}
}
/// <summary>
/// Force the sensor to make a reading and update the relevant properties.
/// </summary>
public void Update()
{
int temp = 0;
//
// Get the humidity first.
//
_groveTH02.WriteRegister(Registers.Config, StartMeasurement);
//
// Maximum conversion time should be 40ms but loop just in case
// it takes longer.
//
Thread.Sleep(40);
while ((_groveTH02.ReadRegister(Registers.Status) & 0x01) > 0)
{
;
}
byte[] data = _groveTH02.ReadRegisters(Registers.DataHigh, 2);
temp = data[0] << 8;
temp |= data[1];
temp >>= 4;
Humidity = (((float)temp) / 16) - 24;
//
// Now get the temperature.
//
_groveTH02.WriteRegister(Registers.Config, StartMeasurement | MeasureTemperature);
//
// Maximum conversion time should be 40ms but loop just in case
// it takes longer.
//
Thread.Sleep(40);
while ((_groveTH02.ReadRegister(Registers.Status) & 0x01) > 0)
{
;
}
data = _groveTH02.ReadRegisters(Registers.DataHigh, 2);
temp = data[0] << 8;
temp |= data[1];
temp >>= 2;
Temperature = (((float)temp) / 32) - 50;
}
/// <summary>
/// Update the Temperature property.
/// </summary>
public void Update()
{
var temperatureData = _tmp102.ReadRegisters(0x00, 2);
var sensorReading = 0;
if (SensorResolution == Resolution.Resolution12Bits)
{
sensorReading = (temperatureData[0] << 4) | (temperatureData[1] >> 4);
}
else
{
sensorReading = (temperatureData[0] << 5) | (temperatureData[1] >> 3);
}
Temperature = (float)(sensorReading * 0.0625);
}
/// <summary>
/// Force a read of the current sensor values and update the Temperature
/// and Pressure properties.
/// </summary>
public void Update()
{
//
// Force the sensor to make a reading by setting the OST bit in Control
// register 1 (see 7.17.1 of the datasheet).
//
Standby = false;
//
// Pause until both temperature and pressure readings are available.
//
while ((Status & 0x06) != 0x06)
{
Thread.Sleep(5);
}
Thread.Sleep(100);
var data = _mpl3115a2.ReadRegisters(Registers.PressureMSB, 5);
Pressure = DecodePresssure(data[0], data[1], data[2]);
Temperature = DecodeTemperature(data[3], data[4]);
}
/// <summary>
/// Create a new MPL115A2 temperature and humidity sensor object.
/// </summary>
/// <param name="address">Sensor address (default to 0x60).</param>
/// <param name="speed">Speed of the I2C interface (default to 100 KHz).</param>
/// <param name="updateInterval">Number of milliseconds between samples (0 indicates polling to be used)</param>
/// <param name="temperatureChangeNotificationThreshold">Changes in temperature greater than this value will trigger an event when updatePeriod > 0.</param>
/// <param name="pressureChangedNotificationThreshold">Changes in pressure greater than this value will trigger an event when updatePeriod > 0.</param>
public MPL115A2(byte address = 0x60, ushort speed = 100, ushort updateInterval = MinimumPollingPeriod,
float temperatureChangeNotificationThreshold = 0.001F, float pressureChangedNotificationThreshold = 10.0F)
{
if ((speed < 10) || (speed > 1000))
{
throw new ArgumentOutOfRangeException(nameof(speed), "Speed should be 10 KHz to 3,400 KHz.");
}
if (temperatureChangeNotificationThreshold < 0)
{
throw new ArgumentOutOfRangeException(nameof(temperatureChangeNotificationThreshold), "Temperature threshold should be >= 0");
}
if (pressureChangedNotificationThreshold < 0)
{
throw new ArgumentOutOfRangeException(nameof(pressureChangedNotificationThreshold), "Pressure threshold should be >= 0");
}
if ((updateInterval != 0) && (updateInterval < MinimumPollingPeriod))
{
throw new ArgumentOutOfRangeException(nameof(updateInterval), "Update period should be 0 or >= than " + MinimumPollingPeriod);
}
TemperatureChangeNotificationThreshold = temperatureChangeNotificationThreshold;
PressureChangeNotificationThreshold = pressureChangedNotificationThreshold;
_updateInterval = updateInterval;
var device = new I2cBus(address, speed);
_mpl115a2 = device;
//
// Update the compensation data from the sensor. The location and format of the
// compensation data can be found on pages 5 and 6 of the datasheet.
//
var data = _mpl115a2.ReadRegisters(Registers.A0MSB, 8);
var a0 = (short)(ushort)((data[0] << 8) | data[1]);
var b1 = (short)(ushort)((data[2] << 8) | data[3]);
var b2 = (short)(ushort)((data[4] << 8) | data[5]);
var c12 = (short)(ushort)(((data[6] << 8) | data[7]) >> 2);
//
// Convert the raw compensation coefficients from the sensor into the
// doubleing point equivalents to speed up the calculations when readings
// are made.
//
// Datasheet, section 3.1
// a0 is signed with 12 integer bits followed by 3 fractional bits so divide by 2^3 (8)
//
_coefficients.A0 = (double)a0 / 8;
//
// b1 is 2 integer bits followed by 7 fractional bits. The lower bits are all 0
// so the format is:
// sign i1 I0 F12...F0
//
// So we need to divide by 2^13 (8192)
//
_coefficients.B1 = (double)b1 / 8192;
//
// b2 is signed integer (1 bit) followed by 14 fractional bits so divide by 2^14 (16384).
//
_coefficients.B2 = (double)b2 / 16384;
//
// c12 is signed with no integer bits but padded with 9 zeroes:
// sign 0.000 000 000 f12...f0
//
// So we need to divide by 2^22 (4,194,304) - 13 doubleing point bits
// plus 9 leading zeroes.
//
_coefficients.C12 = (double)c12 / 4194304;
if (updateInterval > 0)
{
StartUpdating();
}
else
{
Update();
}
}
/// <summary>
/// Display the registers.
/// </summary>
public void DisplayRegisters()
{
var data = _ds323x.ReadRegisters(0, 0x12);
DebugInformation.DisplayRegisters(0, data);
}
