public bool read(byte[] buffer, int expectedBytes)
{
try
{
if (expectedBytes == 0)
{
return(true);
}
int timeout = 10000;
int readResult = 0;
while (timeout > 0 && readResult == 0)
{
readResult = printer.ReadSerialFromHost(buffer, expectedBytes);
if (readResult != expectedBytes)
{
timeout--;
Thread.Sleep(10);
}
}
if (timeout == 0)
{
var message = Encoding.UTF8.GetBytes("TIMEOUT" + char.MinValue);
printer.WriteSerialToHost(message, message.Length);
return(false);
}
return(true);
}
catch (Exception e)
{
System.Console.WriteLine(e.StackTrace);
return(false);
}
}
// Handle incoming commands from the serial link
void Process()
{
// Todo - receive incoming commands from the serial link and act on those commands by calling the low-level hardwarwe APIs, etc.
while (!fDone)
{
byte[] header = ReadPacket(printer, 4);
byte length = header[1];
byte[] response;
if (header.Any(b => b != 0))
{
//Console.WriteLine("\nFirmware sending to host: ");
//for (int i = 0; i < header.Length; i++)
//{
// Console.Write(" ");
// Console.Write(header[i]);
//}
printer.WriteSerialToHost(header, 4);
byte[] ack = ReadPacket(printer, 1);
if (ack[0] == 0xA5)
{
byte[] data = ReadPacket(printer, length);
if (data.Length == 0)
{
response = Encoding.ASCII.GetBytes("Timeout");
}
else
{
ushort checksum = FindChecksum(header[0], data, data.Length);
//Console.WriteLine("Host Checksum: " + header[2] + header[3] + "\n");
//Console.WriteLine("Firmware checksum: " + BitConverter.GetBytes(checksum)[0] + BitConverter.GetBytes(checksum)[1]);
if ((header[2] == BitConverter.GetBytes(checksum)[0]) && (header[3] == BitConverter.GetBytes(checksum)[1]))
{
response = ProcessCmd(header[0], data);
}
else
{
response = Encoding.ASCII.GetBytes("CHECKSUM");
}
}
//Console.WriteLine("\nFirmware sending response to host: ");
byte[] nullByte = { (byte)0 };
response = response.Concat(nullByte).ToArray();
//for (int i = 0; i < response.Length; i++)
//{
// Console.Write(" ");
// Console.Write(response[i]);
//}
printer.WriteSerialToHost(response, response.Length);
}
}
}
}
void ReceiveHeaderAndSend(byte[] headerReceived)
{
int bytesRead = 0;
while (bytesRead < 1)
{
bytesRead = printer.ReadSerialFromHost(headerReceived, 4);
}
printer.WriteSerialToHost(headerReceived, 4);
}
void Process()
{
byte[] value = new byte[HEADER_SIZE];
byte[] cmdParams = new byte[64];
int bytesRead = 0;
string retString = "";
int timeout;
while (!fDone)
{
do // Wait for command byte
{
bytesRead = printer.ReadSerialFromHost(value, HEADER_SIZE); // Read command, length, and checksum
} while (!fDone && bytesRead == 0);
// Console.WriteLine("Process: {0} {1}", value[0], value[1]);
if (!fDone && bytesRead == HEADER_SIZE) // Successfully read command byte, length byte, and checksum bytes
{
// Write header back to host
printer.WriteSerialToHost(value, HEADER_SIZE);
byte[] ACKNAK = new byte[2];
ACKNAK[0] = 0;
do // Wait for ACK/NACK byte
{
bytesRead = printer.ReadSerialFromHost(ACKNAK, 1); // Read ACK/NAK
} while (!fDone && bytesRead == 0);
if (ACKNAK[0] == ACK_BYTE)
{
timeout = 0;
if (value[1] > 0)
{
do
{
timeout++;
} while ((bytesRead = printer.ReadSerialFromHost(cmdParams, value[1])) == 0 && timeout < TIMEOUT_THRESHOLD); // Read in the parameters
}
if (timeout == TIMEOUT_THRESHOLD)
{
retString = "TIMEOUT";
}
else
{
// Validate checksum
short checkSum = (byte)(value[0] + value[1]);
short targetCheckSum = (short)(((short)value[3] << 8) + value[2]);
for (int i = 0; i < value[1]; i++)
{
checkSum += cmdParams[i];
}
if (checkSum == targetCheckSum) // Valid checksum, proceed
{
if (value[0] != FWCommands.CMD_BUFFER)
{
retString = DoCommand(value[0], cmdParams, 0);
}
else // Process command buffer
{
while (cmdParams[0] != FWCommands.CMD_INVALID)
{
byte Ndx = 0;
byte bufferLen = value[1];
byte cmd = cmdParams[Ndx++];
byte len = cmdParams[Ndx++];
Ndx += len;
retString = DoCommand(cmd, cmdParams, 2);
// Delete used command
for (byte i = 0; i < bufferLen - (len + 2); i++)
{
cmdParams[i] = cmdParams[len + 2 + i];
}
for (byte i = (byte)(bufferLen - (len + 2)); i < bufferLen; i++)
{
cmdParams[i] = FWCommands.CMD_INVALID;
}
}
}
}
else
{
retString = "CHECKSUM";
}
} // If no TIMEOUT
printer.WriteSerialToHost(retString.Select(c => (byte)c).ToArray(), retString.Length);
value[0] = 0;
printer.WriteSerialToHost(value, 1);
} // if ACK'd
}
}
}
string FirmwareToHost(PrinterControl printer) // took out byte[] packet, // need to change the return type to the same as the host side
{
//Firmware-to-Host Communication Procedure
int header_size = 4; // 4 is header size
int response_size = 1; // UNSURE OF SIZE OF RESPONSE
int ACK_NAK_size = 1; // size of both ACK and NAK bytes
byte[] ACK = { 0xA5 }; // ACK byte
byte[] NAK = { 0xFF }; // ACK byte
string timeout = "TIMEOUT";
string success = "SUCCESS";
string checksum = "CHECKSUM";
string nak = "NAK";
// Read 4-byte header from host
byte[] header_recieved = new byte[header_size];
// wait for bytes to be recieved
while (printer.ReadSerialFromHost(header_recieved, header_size) < header_size) // the function returns header_bytes_recieved
{
; // wait
}
ClearBuffer(printer); // This should clear the buffer
printByteArray(header_recieved, "Firmware received header");
// Write 4-byte header back to host
byte[] header_sent = header_recieved.ToArray();
printByteArray(header_sent, "Firmware sent header");
int header_bytes_sent = printer.WriteSerialToHost(header_sent, header_size);
// Read ACK/NAK byte
byte[] ACK_NAK = { 0x00 }; // change this to a one element array with nothing in it
while (printer.ReadSerialFromHost(ACK_NAK, ACK_NAK_size) < 1) // function inside returns ACK_NAK_recieved (int)
{
; // wait
}
//ClearBuffer(printer); // This should clear the buffer
printByteArray(ACK_NAK, "Firmware received ACK or NAK");
// If ACK received
if (ACK_NAK.SequenceEqual(ACK))
{
// Attempt to read number of parameter bytes indicated in command header
int num_bytes_rest = (int)(header_recieved[1]); // header_recieved[1] is the number of bytes in the rest of the packet
byte[] rest_bytes = new byte[num_bytes_rest];
int rest_bytes_recieved = 0;
// header_recieved[1] should be rest of packet size
int test_count = 0;
bool timeout_test = false;
while ((rest_bytes_recieved = printer.ReadSerialFromHost(rest_bytes, num_bytes_rest)) < num_bytes_rest) // function inside returns rest_bytes_recieved
{
// wait
if (rest_bytes_recieved < num_bytes_rest && test_count >= 100)
{
timeout_test = true;
break;
}
}
ClearBuffer(printer); // This should clear the buffer
printByteArray(rest_bytes, "Firmware received data");
// If insufficient bytes are received
if (timeout_test) // if number of bytes recieved is less than number of bytes sent
{
// return “TIMEOUT”
byte[] response_bytes = ResponseMaker(timeout);
printByteArray(response_bytes, "Firmware sent response");
int response_bytes_sent = printer.WriteSerialToHost(response_bytes, response_size);
return(timeout);
}
else
{
// Validate checksum(Be sure NOT to include checksum values themselves)
byte[] combined = new byte[header_recieved.Length + rest_bytes.Length]; // change header_revcieved.,length to header_size
System.Buffer.BlockCopy(header_recieved, 0, combined, 0, header_recieved.Length);
System.Buffer.BlockCopy(rest_bytes, 0, combined, 4, rest_bytes.Length);
byte[] combined_checksum = Checksum(combined); // compare bytes 2 and 3 from both the header and what is recieved by adding up both parts: header and rest
var combined_checksum_bytes = combined_checksum.Skip(2).Take(2).ToArray();
var header_checksum_bytes = header_recieved.Skip(2).Take(2).ToArray();
// If checksum correct
if (combined_checksum_bytes.SequenceEqual(header_checksum_bytes)) // .SequenceEqual checks the actual value
{
// Combined should be the packet without the checksum. make sure
// Process // TYLER's Section
ProcessCommand(combined, printer); // change from packet to actual packet that goes into the function // how can this work without returning????
// Return “SUCCESS” or “VERSION n.n”
byte[] response_bytes = ResponseMaker(success);
printByteArray(response_bytes, "Firmware sent Success or Version response");
int response_bytes_sent = printer.WriteSerialToHost(response_bytes, response_bytes.Length);
//ClearBuffer(printer); // This should clear the buffer
return(success); // SUCCESS
}
// Else
else
{
// Return “CHECKSUM”
byte[] response_bytes = ResponseMaker(checksum);
printByteArray(response_bytes, "Firmware sent Checksum response");
int response_bytes_sent = printer.WriteSerialToHost(response_bytes, response_bytes.Length);
return(checksum); // CHECKSUM
}
}
}
// Else if NAK received
else if (ACK_NAK.SequenceEqual(NAK))
{
//ClearBuffer(printer);
// Ignore command – it will be resent
return(nak);
}
else
{ // BANDAID
int max_size = 20;
byte[] nak_byte = new byte[response_size];
byte[] nak_bytes = new byte[max_size];
int num_received = 0;
int i = 0;
while (true) // might get hung up here
{
num_received = printer.ReadSerialFromHost(nak_byte, 1);
if (num_received == 1)
{
i++; // ++'s the number of bytes received
nak_bytes[i] = nak_byte[nak_byte.Length - 1]; // fills the byte[] with the bytes starting at 1 for some reason
num_received = 0; // resets num_received
}
// NAK[0] because one byte long
if (nak_bytes[i] == NAK[0]) // should I use .SequenceEqual()?
{
break; // exit the wait loop
}
}
ClearBuffer(printer); // This should clear the buffer
return("Found the bloody NAK"); // should never get to this but it does
}
}