//-------------------------------------------------------------------------------------------------------------------------------------------
private byte GetVariableIndexFromBuffer(byte command_byte, byte[] buffer)
{
byte index_high_nibble = buffer[1];
byte index_low_nibble = buffer[2];
byte index = NumberConversions.HexStringToByte(new String(new char[] { (char)index_high_nibble, (char)index_low_nibble }));
Debug.Print("Command 0x" + NumberConversions.ByteToHexString(command_byte) + ": variable index = " + index.ToString());
return(index);
}
//-------------------------------------------------------------------------------------------------------------------------------------------
private byte GetByteValueFromBuffer(byte command_byte, byte[] buffer)
{
byte value_high_nibble = buffer[3];
byte value_low_nibble = buffer[4];
byte value = NumberConversions.HexStringToByte(new String(new char[] { (char)value_high_nibble, (char)value_low_nibble }));
Debug.Print("Command 0x" + NumberConversions.ByteToHexString(command_byte) + ": setting with byte value = " + value.ToString());
return(value);
}
//-------------------------------------------------------------------------------------------------------------------------------------------
private ushort GetShortValueFromBuffer(byte command_byte, byte[] buffer)
{
byte msb_value_high_nibble = buffer[3];
byte msb_value_low_nibble = buffer[4];
byte msb = NumberConversions.HexStringToByte(new String(new char[] { (char)msb_value_high_nibble, (char)msb_value_low_nibble }));
byte lsb_value_high_nibble = buffer[5];
byte lsb_value_low_nibble = buffer[6];
byte lsb = NumberConversions.HexStringToByte(new String(new char[] { (char)lsb_value_high_nibble, (char)lsb_value_low_nibble }));
ushort value = (ushort)(((short)msb << 8) + (short)lsb);
Debug.Print("Command 0x" + NumberConversions.ByteToHexString(command_byte) + ": setting with short value = " + value.ToString());
return(value);
}
//-------------------------------------------------------------------------------------------------------------------------------------------
private bool ValidateCommandPacket(byte command_byte, byte[] buffer)
{
if (buffer.Length < (int)GetCommandPacketLength(command_byte))
{
Debug.Print("ERROR: Command parsing for command 0x" + NumberConversions.ByteToHexString(command_byte) + " (" + ByteToCommandName(command_byte) + ") was skipped because not enough data was available");
return(false);
}
if (buffer[1] == 0 || buffer[2] == 0)
{
Debug.Print("ERROR: Command parsing for command 0x" + NumberConversions.ByteToHexString(command_byte) + " (" + ByteToCommandName(command_byte) + ") failed because of null byte(s) in variable index");
return(false);
}
Debug.Print("Command " + ByteToCommandName(command_byte) + " validation OK");
return(true);
}
//-------------------------------------------------------------------------------------------------------------------------------------------
/// <summary>
/// Returns the command packet and shifts remaining data in RX buffer down
/// </summary>
/// <param name="index_of_command_byte"></param>
/// <returns></returns>
private byte[] ExtractCommandPacketFromRxBuffer(int index_of_command_byte)
{
// the following variables are only used for the debug print statement that is going to
// try to help visualize what's in the buffer, and what is getting extracted for command processing, e.g.
// | command bytes here | rest of buffer here
// print all buffer bytes up to index_of_command_byte
// index_of_command_byte: print | before this position
// print all buffer bytes up to index_of_command_byte + command_packet_length
// print | after last command packet byte
// print rest of buffer bytes
// determine the number of bytes that should be in the command packet, based on the command
byte command_id = _rx_buffer[index_of_command_byte];
byte command_packet_length = GetCommandPacketLength(command_id);
Debug.Print("Handling command ID: " + ByteToCommandName(command_id) + ", expected packet length = " + command_packet_length);
#region VISUALIZATION DEBUG MESSAGE
// now print the debug buffer visualization line
string viz = "";
// print all bytes up to command byte position
for (int i = 0; i < index_of_command_byte; i++)
{
viz += NumberConversions.ByteToHexString(_rx_buffer[i]) + " ";
}
viz += "> ";
// print command packet
for (int i = index_of_command_byte; i < index_of_command_byte + command_packet_length; i++)
{
viz += NumberConversions.ByteToHexString(_rx_buffer[i]) + " ";
if (i == index_of_command_byte + command_packet_length - 1)
{
viz += "< ";
}
}
// print remaining bytes in buffer
for (int i = index_of_command_byte + command_packet_length; i < RX_BUFFER_SIZE; i++)
{
if (_rx_buffer[i] == 0)
{
break;
}
viz += NumberConversions.ByteToHexString(_rx_buffer[i]) + " ";
}
Debug.Print(viz);
#endregion
// now create the array for just the packet
byte[] packet = new byte[command_packet_length];
Array.Copy(_rx_buffer, index_of_command_byte, packet, 0, command_packet_length);
//Debug.Print( "copied command packet from buffer into new packet array");
// we need to save the current _rx_buffer_pointer, because that's the ONLY way we know what the new
// _rx_buffer_pointer should be once we shift down the bits.
int old_rx_buffer_pointer = _rx_buffer_pointer;
// modify the rx buffer and shift down the remaining bytes
_rx_buffer_pointer = index_of_command_byte + command_packet_length; // now it points to the element after the command packet we're handling
// the new rx buffer is where the end of the existing data will end up once we shift all of the bytes down
int new_rx_buffer_pointer = old_rx_buffer_pointer - _rx_buffer_pointer;
Debug.Assert(new_rx_buffer_pointer >= 0, "RX buffer pointer problems!");
//Debug.Print( "rx buffer pointer points at: " + _rx_buffer_pointer);
int bytes_remaining_in_buffer = RX_BUFFER_SIZE - _rx_buffer_pointer;
//Debug.Print( bytes_remaining_in_buffer.ToString() + " bytes left in buffer");
// shift down
//Debug.Print( "shifting down bytes");
for (int i = 0; i < bytes_remaining_in_buffer; i++)
{
_rx_buffer[i] = _rx_buffer[_rx_buffer_pointer + i];
}
//Debug.Print( "clearing remaining space");
// clear remaining space (possibly unnecessary)
for (int i = bytes_remaining_in_buffer; i < RX_BUFFER_SIZE; i++)
{
_rx_buffer[i] = 0;
}
//Debug.Print( "Setting new RX buffer pointer to " + new_rx_buffer_pointer);
_rx_buffer_pointer = new_rx_buffer_pointer;
return(packet);
}
