private void USBWrite(int opcode, byte[] payload)
{
if (serialPort.IsOpen)
{
byte[] packet = DAQPacket.Encode(opcode, payload);
serialPort.Write(packet, 0, packet.Length);
}
}
private int USBRXProcessing(DAQPacket packet)
{
switch (packet.opcode)
{
case Opcodes.txAnalogInA: {
int channel = packet.payload[0];
if (channel < 1 || channel > (analogInChannels.Length / 2))
{
return(1);
}
if (analogInChannels[channel - 1] != null)
{
int sampleNum = (packet.payloadLength - 1) / 2;
int[] values = new int[sampleNum];
for (int i = 0; i < sampleNum; i++)
{
values[i] = (packet.payload[1 + (2 * i)] << 8) + packet.payload[1 + (2 * i + 1)];
}
analogInChannels[channel - 1].AddValues(values);
}
break;
}
case Opcodes.txAnalogInB: {
int channel = packet.payload[0];
if (channel < 1 || channel > (analogInChannels.Length / 2))
{
return(1);
}
channel += 8;
if (analogInChannels[channel - 1] != null)
{
int sampleNum = (packet.payloadLength - 1) / 2;
int[] values = new int[sampleNum];
for (int i = 0; i < sampleNum; i++)
{
values[i] = (packet.payload[1 + (2 * i)] << 8) + packet.payload[1 + (2 * i + 1)];
}
analogInChannels[channel - 1].AddValues(values);
}
break;
}
}
return(0);
}
private void USBRXThread()
{
DAQPacket rxPacket = new DAQPacket();
int index = 0;
int rxDataPacketLength = 0;
byte[] rxDataPacket = new byte[550];
byte[] rxBuffer = new byte[1024];
while (rxUSBThreadRun)
{
if (serialPort.IsOpen)
{
int rxLength = 0;
try {
//rxLength = await serialPort.BaseStream.ReadAsync(rxBuffer, 0, rxBuffer.Length);
rxLength = serialPort.BaseStream.Read(rxBuffer, 0, rxBuffer.Length);
} catch {
return;
}
for (int i = 0; i < rxLength; i++)
{
if (index == 0)
{
//First Byte of package is the Opcode
rxDataPacket[index++] = rxBuffer[i];
}
else if (index == 1)
{
//Second and Third byte of package is the length
rxDataPacket[index++] = rxBuffer[i];
rxDataPacketLength = (rxBuffer[i] << 8);
}
else if (index == 2)
{
//Second and Third byte of package is the length
rxDataPacket[index++] = rxBuffer[i];
rxDataPacketLength += rxBuffer[i];
if (rxDataPacketLength > 512)
{
//RX Buffer overflow
index = 0;
usbRXErrorCount += 1;
}
}
else if (index < (rxDataPacketLength + 3 + 2))
{
//Rest bytes are payload
rxDataPacket[index++] = rxBuffer[i];
}
else
{
//Full packet received
rxPacket.Decode(rxDataPacket);
if (USBRXProcessing(rxPacket) != 0)
{
//Packet Processing Error
usbRXErrorCount += 1;
}
usbRXPacketCount += 1;
index = 0;
}
}
usbRXByteCount += rxLength;
if (usbRXStopwatch.ElapsedMilliseconds > 1000)
{
usbRXDatarate = (float)usbRXByteCount;
usbRXByteCount = 0;
usbRXErrorRate = (float)usbRXErrorCount;
usbRXErrorCount = 0;
usbRXStopwatch.Restart();
}
}
}
}