private void ReadData()
{
dataCollection = new Dictionary <string, List <GsrPpgPacket> >()
{
["GSR"] = new List <GsrPpgPacket>(),
["PPG"] = new List <GsrPpgPacket>()
};
int data_rx = 0;
bool receivingData = false;
bool wasPPG = false;
int byteCount = 0;
int data = 0;
var stopwatch = new Stopwatch();
stopwatch.Start();
while (reading)
{
data_rx = base.ReadByte();
// start bit detected. ready to receive data
if (!receivingData && (data_rx & 0x1) == 0x0)
{
byteCount = 0;
receivingData = true;
}
// receiving data
else if (receivingData && (data_rx & 0x1) == 0x1)
{
switch (byteCount)
{
case 0:
// check if this data is PPG
wasPPG = (data_rx & 0x02) != 0;
data = (data_rx & 0xfc) >> 2;
byteCount += 1;
break;
case 1:
// check if data is continuous. if not, it's an error
if (wasPPG != ((data_rx & 0x02) != 0))
{
byteCount = 0;
receivingData = false;
break;
}
data += (data_rx & 0xfc) << 4;
byteCount += 1;
break;
case 2:
// check if data is continuous. if not, it's an error
if (wasPPG != ((data_rx & 0x02) != 0))
{
byteCount = 0;
receivingData = false;
break;
}
data += (data_rx & 0xfc) << 10;
var packetReceivedTickCount = stopwatch.ElapsedTicks;
DataArrivedEventArgs args = new DataArrivedEventArgs {
Timestamp = packetReceivedTickCount, Data = data
};
if (wasPPG)
{
dataCollection["PPG"].Add(new GsrPpgPacket(data, packetReceivedTickCount));
OnPpgDataArrived(args);
}
else
{
dataCollection["GSR"].Add(new GsrPpgPacket(data, packetReceivedTickCount));
OnGsrDataArrived(args);
}
// clean up
byteCount = 0;
receivingData = false;
break;
}
}
// dirty data, ready for receive new data
else
{
byteCount = 0;
receivingData = false;
}
}
}
protected virtual void OnPpgDataArrived(DataArrivedEventArgs e)
{
PpgDataArrived?.Invoke(this, e);
}
