// Sends a message to the Arduino and updates ArduinoBoard member variables upon receiving the response
public async Task Communicate(DATACATEGORY cat, SUBCATEGORY subcat, ACTION action, object data = null, double timeoutLength = -1.0)
{
// Throws an ArduinoCommunicationException if unsuccessful
Console.WriteLine("In Communicate. The current thread is {0}", Thread.CurrentThread.ManagedThreadId.ToString());
List <byte> resp = new List <byte>();
try
{
// Send data to Arduino and get the raw response:
resp = await CommunicateRaw(cat, subcat, action, data, timeoutLength);
}
catch (Exception)
{
throw;
}
// Process the response received from the Arduino:
switch (cat)
{
case DATACATEGORY.NULL:
// I'm not sure what sorts of repsonses would be in this category, if any, since I don't know anything that would be sent in this category
throw new ArduinoCommunicationException("The response was of the NULL category.");
case DATACATEGORY.PING:
if (resp.Count == 5 && resp[0] == sotb && resp[1] == 0x01 && resp[2] == 0xF0 && resp[4] == eotb)
{
if (resp[3] == 0x00 || resp[3] == 0x01)
{
TestStarted = Convert.ToBoolean(resp[3]);
return;
}
else
{
throw new ArduinoCommunicationException("Ping failed: Response contained an invalid value.");
}
}
else
{
throw new ArduinoCommunicationException("Ping failed: Invalid response.");
}
case DATACATEGORY.CONFIG:
if (action == ACTION.READVAR)
{
if (subcat == SUBCATEGORY.ALL)
{
// Check for sot and eot ? When should that be done ?
if (resp.Count > 46 || resp.Count < 9)
{
throw new ArduinoCommunicationException("The response string is of the wrong length.");
}
if (resp[1] != (byte)DATACATEGORY.CONFIG && resp[2] != (byte)((byte)action | (byte)subcat))
{
throw new ArduinoCommunicationException("The response string contains the wrong request code.");
}
int nullterm = resp.IndexOf(0x00, 3);
if (nullterm == -1)
{
throw new ArduinoCommunicationException("Could not parse the Package Name from the response string.");
}
else
{
// As always, use Windows-1252 encoding for chars and strings sent over serial:
PackageName = Encoding.GetEncoding(1252).GetString(resp.ToArray(), 3, nullterm - 3);
}
int nullterm2 = resp.IndexOf(0x00, nullterm + 1);
if (nullterm2 == -1)
{
throw new ArduinoCommunicationException("Could not parse the Test Duration from the response string.");
}
else
{
TestDuration = uint.Parse(Encoding.GetEncoding(1252).GetString(resp.GetRange(nullterm + 1, nullterm2 - nullterm - 1).ToArray()), System.Globalization.NumberStyles.HexNumber);
}
if (resp.Count < nullterm2 + 4)
{
throw new ArduinoCommunicationException("The response string is of the wrong length.");
}
// The start delay in seconds as a byte (the 0x4 is to correct for avoiding sending sot or eot over serial. Arduino side adds 0x4 before sending.)
StartDelay = (byte)(resp[nullterm2 + 1] - 0x4);
// The sample period in seconds as a float
SamplePeriod = ((byte)(resp[nullterm2 + 2] - 0x4)) / 8.0f;
Console.WriteLine("Done parsing the config response.");
return;
}
else
{
// Not implemented yet
throw new ArduinoCommunicationException("Error, not implemented yet...");
}
}
else if (action == ACTION.WRITEVAR || action == ACTION.SENDCOMMAND)
{
switch (subcat)
{
case SUBCATEGORY.PACKAGE_NAME:
if (resp.Count == 4 && resp[1] == (byte)cat && resp[2] == (byte)((byte)action | (byte)subcat))
{
PackageName = (string)data; // Success. Can update this now.
return;
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
case SUBCATEGORY.TEST_DUR:
if (resp.Count == 4 && resp[1] == (byte)cat && resp[2] == (byte)((byte)action | (byte)subcat))
{
TestDuration = (uint)data; // Success. Can update this now.
return;
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
case SUBCATEGORY.SAMPLE_PERIOD:
if (resp.Count == 4 && resp[1] == (byte)cat && resp[2] == (byte)((byte)action | (byte)subcat))
{
SamplePeriod = (float)data; // Success. Can update this now.
return;
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
case SUBCATEGORY.START_DELAY:
if (resp.Count == 4 && resp[1] == (byte)cat && resp[2] == (byte)((byte)action | (byte)subcat))
{
StartDelay = Convert.ToByte((int)data); // Success. Can update this now.
return;
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
// Implement the rest of the cases later
default:
throw new ArduinoCommunicationException("Error, not implemented yet...");
}
}
else
{
// invalid action type
throw new ArduinoCommunicationException("Invalid communication action type.");
}
case DATACATEGORY.OTHER:
if (action == ACTION.SENDCOMMAND || action == ACTION.WRITEVAR)
{
switch (subcat)
{
case SUBCATEGORY.START_TEST:
case SUBCATEGORY.STOP_TEST:
if (resp.Count == 5 && resp[1] == (byte)cat && resp[2] == (byte)((byte)action | (byte)subcat))
{
if (resp[3] == 0x00 || resp[3] == 0x01)
{
TestStarted = Convert.ToBoolean(resp[3] & 0x01);
return;
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
case SUBCATEGORY.TIME_DATE:
if (resp.Count == 4 && resp[1] == (byte)cat && resp[2] == (byte)((byte)action | (byte)subcat))
{
return;
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
default:
throw new ArduinoCommunicationException("Error, not implemented yet...");
}
}
else if (action == ACTION.READVAR)
{
if (subcat == SUBCATEGORY.TIME_DATE)
{
if (resp.Count == 11 && resp[1] == (byte)cat && resp[2] == (byte)((byte)action | (byte)subcat))
{
// Set local copy of Arduino's RTC time here
throw new ArduinoCommunicationException("Error, not implemented yet...");
}
else
{
throw new ArduinoCommunicationException("The response didn't match the expected value.");
}
}
else
{
throw new ArduinoCommunicationException("Error, not implemented yet...");
}
}
else
{
// invalid action type
throw new ArduinoCommunicationException("Invalid communication action type.");
}
default:
throw new ArduinoCommunicationException("The response is of an invalid category.");
}
}
// Gets a timeout length in milliseconds
private double _GetTimeoutLength(DATACATEGORY cat, SUBCATEGORY subcat, ACTION action, object data = null)
{
// Different kinds of communication take different amounts of time, so maybe you'd want to adjust the timeout length based on that.
// For now, this method is a placeholder
return(600.0); // 600 ms (placeholder)
}
// Sends a message to the Arduino and returns its response
private async Task <List <byte> > CommunicateRaw(DATACATEGORY cat, SUBCATEGORY subcat, ACTION action, object data = null, double timeoutLength = -1.0)
{
// Returns the raw response without validating it.
// If there is no response or if some other kind of error occurs, it throws an ArduinoCommunicationException exception.
bool gotLock = false;
try
{
// Spin for up to 500 ms trying to enter into communication
commLock.TryEnter(500, ref gotLock);
if (!gotLock) // Don't enter the critical section if the lock wasn't acquired.
{
Console.WriteLine("Could not enter critical section. Lock is held by another thread. ");
throw new ArduinoCommunicationException("Serial port is busy. Could not enter critical section.");
}
if (Port == null || !Port.IsOpen)
{
if (gotLock)
{
commLock.Exit(false);
}
throw new ArduinoCommunicationException("The serial port is null or not open.");
}
// The timeoutLength is the total time in milliseconds between just before the data is sent and right after the response is received.
if (timeoutLength < 0.0) // If the user didn't specify a timeout length
{
// Use the recommended timeout length for the type of communication you're using
timeoutLength = _GetTimeoutLength(cat, subcat, action, data); // Returns a placeholder value for now
}
bool noResponse = true;
if (_ExpectedResponseCancellation.IsCancellationRequested)
{
_ExpectedResponseCancellation = new CancellationTokenSource();
Console.WriteLine("Made new cancellation token."); // Just for debugging
}
// try using the token.register thing?
_ReceivedBytes.Clear(); // This should be ok b/c we have the commLock. But is One-Way communication data safe?
_ReceivedTwoWayData.Clear();
SendData(cat, subcat, action, data); // Send the data
try
{
// Wait until timeout or until response is received
Task.Delay(TimeSpan.FromMilliseconds(timeoutLength), _ExpectedResponseCancellation.Token).Wait();
Console.WriteLine("---No longer waiting for a response!!!");
}
catch (TaskCanceledException)
{
noResponse = false;
Console.WriteLine("Canceled the delay for the response.");
}
catch (AggregateException ex) // Hmmm. There could be a legit bad exception that it lets through
{
AggregateException aggregateException = ex.Flatten();
foreach (var inner_ex in ex.InnerExceptions)
{
if (inner_ex is TaskCanceledException)
{
noResponse = false;
}
}
if (noResponse)
{
throw ex;
}
}
catch (Exception ex)
{
throw ex;
}
// These were both uncommented before: (2/24/2019)
//_ExpectedResponseCancellation.Dispose();
//_ExpectedResponseCancellation = new CancellationTokenSource(); // Create new one for next time
if (noResponse)
{
throw new ArduinoCommunicationException("No response.");
}
List <byte> resp_data_bytes = new List <byte>();
resp_data_bytes.AddRange(_ReceivedTwoWayData);
_ReceivedTwoWayData.Clear();
Console.WriteLine("### CommunicateRaw. Received: {0}\n......Which is the same as: {1}", BytesToString(resp_data_bytes), BitConverter.ToString(resp_data_bytes.ToArray()));
if (gotLock)
{
commLock.Exit(false);
}
return(resp_data_bytes);
}
catch (Exception e)
{
Console.WriteLine("In CommunicateRaw: Exception caught: " + e.Message);
// Only give up the lock if you actually acquired it
if (gotLock)
{
commLock.Exit(false);
throw;
}
else
{
throw new ArduinoCommunicationException("Exception in CommunicateRaw. ", e);
}
}
finally
{
// Only give up the lock if you actually acquired it
//if (gotLock) commLock.Exit();
//throw new ArduinoCommunicationException("In CommunicateRaw in finally. You should never see this exception! ");
//Console.WriteLine("In CommunicateRaw in finally. You should never see this! ");
}
}
// Sends data over serial
public void SendData(DATACATEGORY cat, SUBCATEGORY subcat, ACTION action, object data = null)
{
// Need to check for invalid input in this method!!!!
// Return a COMMERROR ? An maybe change everything over to Exceptions (b/c some errors already begin as exceptions, and they are more detailed in description and don't require a special Response class)?
switch (cat)
{
case DATACATEGORY.NULL: // Not used. Or maybe it could have a use later?
// cat = 0
SendData(new byte[] { (byte)cat, 0x00 });
break;
case DATACATEGORY.PING:
// cat = 1
SendData(new byte[] { (byte)cat, 0xF0 });
break;
case DATACATEGORY.CONFIG:
// cat = 2. The first hex is F just so that the byte isn't 0x02, which is sot (start of text).
if ((byte)subcat == (byte)SUBCATEGORY.SAMPLE_PERIOD && data != null) // Write sample period
{
SendData(new byte[] { (byte)cat, (byte)((byte)action | (byte)subcat), (byte)(((float)data) * 8.0 + 4.0) });
}
else if ((byte)subcat == (byte)SUBCATEGORY.TEST_DUR && data != null) // Write test duration
{
char[] hex = BitConverter.ToString(BitConverter.GetBytes((uint)data).Reverse().ToArray()).Replace("-", "").ToCharArray(); // Converts test duration to ascii-encoded char array
SendData(new byte[] { (byte)cat, (byte)((byte)action | (byte)subcat), (byte)hex[2], (byte)hex[3], (byte)hex[4], (byte)hex[5], (byte)hex[6], (byte)hex[7] }); // cat = 2
}
else if ((byte)subcat == (byte)SUBCATEGORY.PACKAGE_NAME && data != null) // Write package name
{
List <byte> bytelist = new List <byte>();
bytelist.Add((byte)cat);
bytelist.Add((byte)((byte)action | (byte)subcat));
bytelist.AddRange(StringToBytes((string)data));
SendData(bytelist.ToArray());
}
else if ((byte)subcat == (byte)SUBCATEGORY.START_DELAY && data != null) // Write start delay
{
// Add 4 to the start delay before sending to avoid sending 0x02 or 0x03 which are the special sotb and eotb bytes:
SendData(new byte[] { (byte)cat, (byte)((byte)action | (byte)subcat), Convert.ToByte((int)data + 4) });
}
else // Else use the default case. Used for reading and whatever else
{
SendData(new byte[] { (byte)cat, (byte)((byte)action | (byte)subcat) });
}
break;
case DATACATEGORY.OTHER:
// cat = 3. The first hex is F just so that the byte isn't 0x03, which is eot (end of text).
if (subcat == (byte)SUBCATEGORY.START_TEST || (byte)subcat == (byte)SUBCATEGORY.STOP_TEST) // Start test or stop test
{
SendData(new byte[] { (byte)cat, (byte)((byte)ACTION.SENDCOMMAND | (byte)subcat) });
}
else if ((byte)subcat == (byte)SUBCATEGORY.TIME_DATE) // Set or read time/date
{
if ((action == ACTION.SENDCOMMAND || action == ACTION.WRITEVAR) && data != null)
{
// Set the time and date on the arduino's RTC (real-time clock)
DateTime dt = (DateTime)data;
List <byte> bytelist = new List <byte>();
bytelist.AddRange(new byte[] { (byte)cat, (byte)((byte)action | (byte)subcat), (byte)(dt.Hour + 4), (byte)(dt.Minute + 4), (byte)(dt.Second + 4), (byte)(dt.Month + 4), (byte)(dt.Day + 4) });
bytelist.AddRange(Encoding.GetEncoding(1252).GetBytes(dt.Year.ToString())); // array of extended ascii-encoded bytes representing the year
SendData(bytelist.ToArray());
}
else if (action == ACTION.READVAR)
{
SendData(new byte[] { (byte)cat, (byte)((byte)action | (byte)subcat) });
}
}
// Features not implemented yet:
// Real-time data toggle
// etc.
// Don't forget the 0x02 and 0x03 bytes can't be used
break;
case DATACATEGORY.SENSORS:
// Not implemented yet...
break;
case DATACATEGORY.DATAFILE:
// The two bytes are structured as: (data file # - upper 5b)(cat), (data file # - lower 6b)0(action)
SendData(new byte[] { (byte)((((byte)subcat & 0x7C0) >> 3) | (byte)cat), (byte)((((byte)subcat & 0x3F) << 2) | (byte)action) });
break;
default:
throw new ArduinoCommunicationException("Invalid transmission category.");
}
}