/// <summary>
/// Reads the data from the sensor.
/// </summary>
/// <returns cref="Pms5003Data">The data.</returns>
/// <exception cref="ReadFailedException">Thrown when the read fails.</exception>
public Pms5003Data ReadData()
{
var currentTry = 0;
const int maxRetries = 5;
while (currentTry < maxRetries)
{
try
{
var buffer = new byte[32];
_serialPort.Read(buffer, 0, 32);
return(Pms5003Data.FromBytes(buffer));
}
catch (Exception e)
{
Logger?.LogWarning(e.ToString());
Thread.Sleep(1000);
}
finally
{
currentTry += 1;
}
}
throw new ReadFailedException();
}
/// <summary>
/// Instantiates a new instance from the given byte buffer.
/// </summary>
/// <param name="buffer">The data buffer</param>
/// <returns>A new instance.</returns>
public static Pms5003Data FromBytes(byte[] buffer)
{
var pms5003Measurement = new Pms5003Data();
if (buffer.Length < 4)
{
throw new BufferUnderflowException();
}
if (buffer[0] != Pms5003Constants.StartByte1 || buffer[1] != Pms5003Constants.StartByte2)
{
throw new InvalidStartByteException(buffer[0], buffer[1]);
}
var frameLength = Utils.CombineBytes(buffer[2], buffer[3]);
if (frameLength > 0)
{
var currentDataPoint = 0;
for (var i = 4; i < frameLength + 4; i += 2)
{
pms5003Measurement._data[currentDataPoint] = Utils.CombineBytes(buffer[i], buffer[i + 1]);
currentDataPoint += 1;
}
}
var checkSum = 0;
for (var i = 0; i < frameLength + 2; i++)
{
checkSum += buffer[i];
}
if (pms5003Measurement.Checksum != checkSum)
{
throw new ChecksumMismatchException();
}
return(pms5003Measurement);
}
