private ushort[] runCommand(SGPCommand cmd, ushort[] parameters = null)
{
bus.SetDevice(this.address);
var bytesToWrite = new byte[cmd.OpCode.Length + (cmd.ParameterLength * (WORD_LENGTH + CRC_LENGTH))];
if (cmd.ParameterLength > 0 && parameters?.Length != cmd.ParameterLength)
{
throw new ArgumentException(nameof(parameters));
}
Array.Copy(cmd.OpCode, 0, bytesToWrite, 0, cmd.OpCode.Length);
if (parameters != null)
{
foreach (var i in Enumerable.Range(0, parameters.Length))
{
Span <byte> span = bytesToWrite.AsSpan().Slice(i * (WORD_LENGTH + CRC_LENGTH) + cmd.OpCode.Length, (WORD_LENGTH + CRC_LENGTH));
span[0] = (byte)(parameters[i] >> 8);
span[1] = (byte)(parameters[i] & 0xFF);
span[2] = CRC(span.Slice(0, WORD_LENGTH));
}
}
var argBytes = bytesToWrite.AsSpan(1);
bus.WriteI2cBlockData(bytesToWrite[0], argBytes.ToArray());
Thread.Sleep(cmd.ResponseTimeMs);
if (cmd.ResponseLength > 0)
{
var data = new byte[cmd.ResponseLength * (WORD_LENGTH + CRC_LENGTH)];
bus.ReadI2cBlockData(0, data);
ushort[] result = ReadCheckSummedWords(data);
return(result);
}
return(Array.Empty <ushort>());
}
public void InitAirQuality()
{
SGPCommand cmd = new SGPCommand()
{
OpCode = new byte[] { 0x20, 0x03 },
ResponseLength = 0,
ResponseTimeMs = 10,
ParameterLength = 0
};
var result = this.runCommand(cmd);
}
public void SetBaseline(ushort a, ushort b)
{
SGPCommand cmd = new SGPCommand()
{
OpCode = new byte[] { 0x20, 0x1e },
ResponseLength = 0,
ResponseTimeMs = 10,
ParameterLength = 2
};
this.runCommand(cmd, new ushort[] { a, b });
}
public (ushort Raw_CO2, ushort Raw_VOC) GetBaseline()
{
SGPCommand cmd = new SGPCommand()
{
OpCode = new byte[] { 0x20, 0x15 },
ResponseLength = 2,
ResponseTimeMs = 10,
ParameterLength = 0
};
var result = this.runCommand(cmd);
return(Raw_CO2 : result[0], Raw_VOC : result[1]);
}
public (ushort CO2_PartsPerMillion, ushort VOC_PartsPerMillion) MeasureAirQuality()
{
SGPCommand cmd = new SGPCommand()
{
OpCode = new byte[] { 0x20, 0x08 },
ResponseLength = 2,
ResponseTimeMs = 12,
ParameterLength = 0
};
var result = this.runCommand(cmd);
return(CO2_PartsPerMillion : result[0], VOC_PartsPerMillion : result[1]);
}
public int GetFeatureSetVersion()
{
SGPCommand cmd = new SGPCommand()
{
OpCode = new byte[] { 0x20, 0x2f },
ResponseLength = 1,
ResponseTimeMs = 2,
ParameterLength = 0
};
var result = this.runCommand(cmd);
return(result[0]);
}
public string GetSerialNumber()
{
SGPCommand cmd = new SGPCommand()
{
OpCode = new byte[] { 0x36, 0x82 },
ResponseLength = 3,
ResponseTimeMs = 1,
ParameterLength = 0
};
var result = this.runCommand(cmd);
return(string.Join(" ", result.Select(x => string.Format("0x{0:X4}", x))));
}
