I am using serial port to read the data off the scale that is attached to the thin client. In 99% of cases the data is read correctly - ie whatever is on the scale is what is captured by the application.
However, sometimes, it looks like data is dropped. For instance instead of 90.007 it will be read as 0.007. I am using ReadLine function:
private void CaptureWeight()
{
globalCounter++;
string value = "";
_sp.DiscardInBuffer();
while (!this._processingDone)
{
try
{
value = this._sp.ReadLine();
if (value != "")
{
if (value == "ES")
{
_sp.DiscardInBuffer();
value = "";
}
else
{
this.Invoke(this.OnDataAcquiredEvent, new object[] { value });
}
}
}
catch (TimeoutException)
{
//catch it but do nothing
}
catch
{
//reset the port here?
MessageBox.Show("some other than timeout exception thrown while reading serial port");
}
}
} //end of CaptureWeight()
Don't call DiscardInBuffer. The operating system buffer is filled asynchronously as data is shifted in through the UART. Read all of the data and act on it accordingly because you have no way of knowing what is in the buffer at the time you discard it!
When does "ES" come? It is theory possible that the value immediately after "ES", is not read correctly, because you call DiscardInBuffer(). If in that time the buffer contains part of the next reading, e.g. the 9 in 90.007, the 9 gets discarded and you read 0.007.
Try discarding only everything before the last CR LF. But leave incomplete lines.
Related
I have a master device and ESP32 acting as a slave, communicating directly over UART with RX/TX cables. I've created a task that checks the serial stream every 50 ms and parses the data. My problem is that the serial stream freezes up, seemingly randomly, and only restarts if the master or the slave are restarted.
The task looks as such:
void TaskListen_UART(void *pvParameters)
{
while (true)
{
if (readSerialIn())
{
slaveRunCommand(serialData.command); // Execute received commmand
}
vTaskDelay(50 / portTICK_PERIOD_MS);
}
}
It checks the serial stream through readSerialIn() which looks like the following:
bool readSerialIn()
{
if (UART.available() > 0) // Check if the Serial port received data
{
serialData.clearStruct(); // Clear previously saved data
if (UART.find(0x2A)) // Find "*" // Find starting delimiter
{
serialData.length = UART.read(); // Read length
if (serialData.length > BYTE_BUFFER_LEN)
{
writeSerialNACK(); // Write NACK if length seems incorrect
return false;
}
Serial.printf(("Message length: %d\n"), serialData.length);
serialData.checksum = UART.read(); // Read Checksum
Serial.printf(("Checksum: %d\n"), serialData.checksum);
if (parseBuffer(serialData.length)) // Parse the data
{
if (serialData.checkSum()) // If the checksum passes
{
serialData.assignBuffer(); // Save the parsed data to the global buffer
return true;
}
else
{
writeSerialNACK();
return false;
}
}
else
false;
}
else
return false;
}
}
The parseBuffer() function is what actually reads the stream and parses it into their according values on the slave. I tried to write it in the most fail-safe fashion, but it still hasn't cleared up my issue.
bool parseBuffer(uint8_t bufferLength)
{
uint8_t bufferPos = 0;
bool uartDetectFlag = false;
while (UART.available() > 0)
{
uartDetectFlag = true;
if (bufferPos < bufferLength)
{
serialData.serialBuffer[bufferPos] = UART.read();
}
bufferPos++;
}
if (uartDetectFlag)
return true;
else
return false;
}
At first I was suspicious that the ESP was trying to access a block in memory that doesn't exist. I noticed however that it doesn't reset itself like it normally would if that were the case, and I tried writing parseBuffer in a non-blocking manner. I also tried increasing the task delay to 100 ms, which reduced the frequency of the blocking but did not suffice in terms of speed. Regardless, it freezes up and (I think) it's caused by a large flow of data through the serial stream.
I am trying to modify the multihop Oscilloscope program so that the sink node is able to send data both to UART and radio medium as well. As far as researched, I found out that the same hardware is used for sending packets via UART and radio too.
In this case, how do I modify my code so that I can send data to UART or radio based on a condition I receive. Here in the sample prorgram, I send data via radio on every 10 packets received.
The receive module for my sink node is:
event message_t* Receive.receive(message_t* msg, void *payload, uint8_t len) {
oscilloscope_t* in = (oscilloscope_t*)payload;
counter++;
am_addr_t rec = call AMPacket.source(msg);
oscilloscope_t* out;
counter++;
call Leds.led0On();
if (uartbusy == FALSE) {
out = (oscilloscope_t*)call SerialSend.getPayload(&uartbuf, sizeof(oscilloscope_t));
if (len != sizeof(oscilloscope_t) || out == NULL) {
return msg;
}
else {
memcpy(out, in, sizeof(oscilloscope_t));
}
uartlen = sizeof(oscilloscope_t);
post uartSendTask();
} else {
message_t *newmsg = call UARTMessagePool.get();
if (newmsg == NULL) {
report_problem();
return msg;
}
//Serial port busy, so enqueue.
out = (oscilloscope_t*)call SerialSend.getPayload(newmsg, sizeof(oscilloscope_t));
if (out == NULL) {
return msg;
}
memcpy(out, in, sizeof(oscilloscope_t));
if (call UARTQueue.enqueue(newmsg) != SUCCESS) {
call UARTMessagePool.put(newmsg);
fatal_problem();
return msg;
}
}
if(counter % 10 == 0){
oscilloscope_t* btrpkt = (oscilloscope_t*)(call Packet.getPayload(&pkt, sizeof(oscilloscope_t)));
call Leds.led1On();
if (call AMSend.send(rec, &pkt, sizeof(oscilloscope_t)) == SUCCESS) {
call Leds.led0On();
sendbusy = TRUE;
}
}
return msg;
}
Once the data sends back to the node from where it received the packet , it is unable to process it through UART again. Could anyone help me how could I solve my problem?
According to the question and comments:
You must instantiate AMSenderC with the same id as for the receiver. In this case, AM_OSCILLOSCOPE if you want a message to be processed by the same code. Or another id plus a new implementation of the Receive interface.
You missed putting payload into btrpkt.
You must check for sendbusy - it is a bug if you try to use the radio stack when it is busy.
this will be my first post and I will do my best to be clear and concise. I've checked some of the other posts on this forum but was unable to find a satisfactory answer.
My question pertains to the use of JavaFX and the jSSC(java simple serial connection) library. I've designed a very simple GUI application that will host four different charts. Two of the charts will display readings from temperature and solar sensors for the past hour, while the other two display that data over an extended period -- a 14-hour period. Eventually I would like to make that more flexible and set the application to "sleep" when the readings become roughly zero (night).
How can I stream data to display this data in real time?
After referencing several sources online and from "JavaFX 8 Intro. by Example", I've been able to construct most of the serial connection class. I'm having trouble processing the data readings, so that it can be displayed on the chart.
public class SerialComm implements SerialPortEventListener {
Date time = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("mm");
boolean connected;
StringBuilder sb;
private SerialPort serialPort;
final StringProperty line = new SimpleStringProperty("");
//Not sure this is necessary
private static final String [] PORT_NAMES = {
"/dev/tty.usbmodem1411", // Mac OS X
"COM11", // Windows
};
//Baud rate of communication transfer with serial device
public static final int DATA_RATE = 9600;
//Create a connection with the serial device
public boolean connect() {
String [] ports = SerialPortList.getPortNames();
//First, Find an instance of serial port as set in PORT_NAMES.
for (String port : ports) {
System.out.print("Ports: " + port);
serialPort = new SerialPort(port);
}
if (serialPort == null) {
System.out.println("Could not find device.");
return false;
}
//Operation to perform is port is found
try {
// open serial port
if(serialPort.openPort()) {
System.out.println("Connected");
// set port parameters
serialPort.setParams(DATA_RATE,
SerialPort.DATABITS_8,
SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
serialPort.setEventsMask(SerialPort.MASK_RXCHAR);
serialPort.addEventListener(event -> {
if(event.isRXCHAR()) {
try {
sb.append(serialPort.readString(event.getEventValue()));
String str = sb.toString();
if(str.endsWith("\r\n")) {
line.set(Long.toString(time.getTime()).concat(":").concat(
str.substring(0, str.indexOf("\r\n"))));
System.out.println("line" + line);
sb = new StringBuilder();
}
} catch (SerialPortException ex) {
Logger.getLogger(SerialComm.class.getName()).log(Level.SEVERE, null, ex); }
}
});
}
} catch (Exception e) {
System.out.println("ErrOr");
e.printStackTrace();
System.err.println(e.toString());
}
return serialPort != null;
}
#Override
public void serialEvent(SerialPortEvent spe) {
throw new UnsupportedOperationException("Not supported yet.");
}
public StringProperty getLine() {
return line;
}
}
Within the try block, I understand the port parameters, but the eventListener is where I am having difficulty. The significance of the stringbuilder is to append data the new data as it is read from the device.
How will I account for the two sensor readings? Would I do that by creating separate data rates to differentiate between the incoming data from each sensor??
I hope that this is clear and that I've provided enough information but not too much. Thank you for any assistance.
-------------------------------UPDATE--------------------------
Since your reply Jose, I've started to make the additions to my code. Adding the listener within the JavaFX class, I'm running into some issues. I keep getting a NullPointerException, which I believe is the String[]data not being initialized by any data from the SerialCommunication class.
serialPort.addEventListener(event -> {
if(event.isRXCHAR()) {
try {
sb.append(serialPort.readString(event.getEventValue()));
String str = sb.toString();
if(str.endsWith("\r\n")) {
line.set(Long.toString(time.getTime()).concat(":").concat(
str.substring(0, str.indexOf("\r\n"))));
System.out.println("line" + line);
sb = new StringBuilder();
}
} catch (SerialPortException ex) {
Logger.getLogger(SerialComm.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
}
} catch (Exception e) {
System.err.println(e.toString());
}
I'm adding the time to the data being read. As Jose mentioned below, I've added tags to the data variables within the arduino code, I'm using: Serial.print("Solar:"); Serial.println(solarData);
Rough code of the JavaFx listener:
serialPort.getLine().addListener((ov, t, t1) -> {
Platform.runLater(()-> {
String [] data = t1.split(":");
try {
//data[0] is the timestamp
//data[1] will contain the label printed by arduino "Solar: data"
switch (data[1]) {
case "Solar":
data[0].replace("Solar:" , "");
solarSeries.getData().add(new XYChart.Data(data[0], data[1]));
break;
case "Temperature":
temperatureSeries.getData().add(new XYChart.Data(data[0], data[1]));
break;
}
Is the reason this code has NullPointerException a result of the String [] data array being uninitialized?
Exception Error
Ports: /dev/tty.usbmodem1411Connected
Exception in thread "EventThread /dev/tty.usbmodem1411" java.lang.NullPointerException
at SerialComm.lambda$connect$0(SerialComm.java:61)
at SerialComm$$Lambda$1/1661773475.serialEvent(Unknown Source)
at jssc.SerialPort$LinuxEventThread.run(SerialPort.java:1299)
The SerialPortEventListener defined in the jssc library allows listening for serial port events. One of those events is the RXCHAR event, that occurs when the Arduino board is sending some data and some bytes are on the input buffer.
event.getEventValue() returns an int with the byte count, and serialPort.readString(event.getEventValue()) get the String format from those bytes.
Note that this method does not return a full line, so you need to listen to carriage return and line feed characters. Once you find "\r\n", you can get the line, and reset the StringBuilder for the next one:
sb.append(serialPort.readString(event.getEventValue()));
String str=sb.toString();
if(str.endsWith("\r\n")){
line.set(str.substring(0,str.indexOf("\r\n")));
sb=new StringBuilder();
}
where line is an observable String:
final StringProperty line=new SimpleStringProperty("");
On the Arduino side, if you want to send values from different sensors at different rates, I suggest you define on the Arduino sketch some identification string for each sensor, and you print for each value the id of its sensor.
For instance, these will be the readings you will get with the serial event listener:
ID1,val1
ID1,val2
ID2,val3
ID1,val4
ID3,val5
...
Finally, on the JavaFX thread, define a listener to changes in line and process the String to get the sensor and the value. Something like this:
serial.getLine().addListener(
(ObservableValue<? extends String> observable, String oldValue, String newValue) -> {
Platform.runLater(()->{
String[] data=newValue.split("\\,");
if(data[0].equals("ID1"){
// add to chart from sensor 1, value data[1];
} else if(data[0].equals("ID2"){
// add to chart from sensor 2, value data[1];
} else if(data[0].equals("ID3"){
// add to chart from sensor 3, value data[1];
}
});
});
Note you need to add Platform.runLater(), since the thread that gets the data from serial port and updates line is not on the JavaFX thread.
From my experience, on the Arduino side, add a comma or something to separate the different values when you print and when you receive that string in Java simply split that string by commas.
String[] stringSeparate = str.split(",");
I am trying to retrieve a value from a Zebra printer by interrogating it with this code:
public static string GetSettingFromPrinter(string cmd)
{
string setting = string.Empty;
try
{
BasicPortSettings bps = new BasicPortSettings();
bps.BaudRate = BaudRates.CBR_19200;
bps.Parity = OpenNETCF.IO.Serial.Parity.none;
bps.StopBits = OpenNETCF.IO.Serial.StopBits.one;
Port serialPort = new Port("COM1:", bps);
serialPort.Open();
byte[] sendBytes = Encoding.ASCII.GetBytes(cmd);
MessageBox.Show(Encoding.ASCII.GetString(sendBytes, 0, sendBytes.Length));
serialPort.Output = sendBytes;
serialPort.Query(); // <= this is new
byte[] responseBytes = serialPort.Input;
setting = GetString(responseBytes);
serialPort.Close();
return setting;
}
catch (Exception x)
{
MessageBox.Show(x.ToString());
return setting;
}
}
However, I don't see where the Output is actually sent, or how to do that. My best guess was calling the Port.Query() method, but that doesn't work, either - at least there is nothing in setting / the Port.Input value after doing so.
I have successfully passed commands to the printer using the older SerialPort class:
public static bool SendCommandToPrinter(string cmd)
{
bool success; // init'd to false by default
try
{
SerialPort serialPort = new SerialPort();
serialPort.BaudRate = 19200;
serialPort.Handshake = Handshake.XOnXOff;
serialPort.Open();
serialPort.Write(cmd);
serialPort.Close();
success = true;
}
catch // may not need a try/catch block, as success defaults to false
{
success = false;
}
return success;
}
...but was advised not to use that due to its longness of tooth.
I would revert back to this snaggletooth if I knew how to read from the old SerialPort class. Does anybody know what I need to do to send sendBytes (and receive responseBytes)?
UPDATE
I tested "COM1" instead of "COM1:" (I used the latter because there is a post that says the colon is necessary (<= not medical advice, although that is doubtless true in that sense, too), but sans the ":" made no noticeable difference.
I then tried "string.Empty" in place of giving it a name, and got, "OpenNETCF.IO.Serial.CommPortException: CreateFileFailed 2 ..."
Onward...or is it Sideward...
FWIW, setting the Output property immediately sends the data on the wire. No additional call is necessary.
I have direct show filter which takes an input and process it and give the result to outputpin.
I want to write this filter output data to a file...And i want to do it in its filter class.So i want to get the output pin buffer data.
Shortly how to reach final data of outputpin in its filter? How can i do it?
Not: The output pin is derived from CBaseOutputPin.This is an open source filter it "magically" :-) put wright data to its output pin which i can not figure out how yet...
Update:
Here is the siutuation:
Media Source ----> GFilter ----> FileWriter
I have source code of GFilter... I have no source code of FileWriter...What i want to make is make GFilter write its own data...I debug GFilter get some insight how its transform data but my attemp to write this data result with wrong data... So i deceide for now how to simply get data at its output pin...
Update[2]
In Filter outputpin somwhere the filter writer pass the file writer pin to IStreamPtr variable...Everthing seems to written to a variable m_pIStream which is type of [IStreamPtr]
GFilterOutput::CompleteConnect(IPin *pReceivePin)
{
// make sure that this is the file writer, supporting
// IStream, or we will not be able to write out the metadata
// at stop time
// m_pIStream is IStreamPtr type
m_pIStream = pReceivePin;
if (m_pIStream == NULL)
{
return E_NOINTERFACE;
}
return CBaseOutputPin::CompleteConnect(pReceivePin);
}
...
GFilterOutput::Replace(LONGLONG pos, const BYTE* pBuffer, long cBytes)
{
//OutputDebugStringA("DEBUG: Now at MuxOutput Replace");
// all media content is written when the graph is running,
// using IMemInputPin. On stop (during our stop, but after the
// file writer has stopped), we switch to IStream for the metadata.
// The in-memory index is updated after a successful call to this function, so
// any data not written on completion of Stop will not be in the index.
CAutoLock lock(&m_csWrite);
HRESULT hr = S_OK;
if (m_bUseIStream)
{
IStreamPtr pStream = GetConnected();
if (m_pIStream == NULL)
{
hr = E_NOINTERFACE;
} else {
LARGE_INTEGER liTo;
liTo.QuadPart = pos;
ULARGE_INTEGER uliUnused;
hr = m_pIStream->Seek(liTo, STREAM_SEEK_SET, &uliUnused);
if (SUCCEEDED(hr))
{
ULONG cActual;
hr = m_pIStream->Write(pBuffer, cBytes, &cActual);
if (SUCCEEDED(hr) && ((long)cActual != cBytes))
{
hr = E_FAIL;
}
}
}
} else {
// where the buffer boundaries lie is not important in this
// case, so break writes up into the buffers.
while (cBytes && (hr == S_OK))
{
IMediaSamplePtr pSample;
hr = GetDeliveryBuffer(&pSample, NULL, NULL, 0);
if (SUCCEEDED(hr))
{
long cThis = min(pSample->GetSize(), cBytes);
BYTE* pDest;
pSample->GetPointer(&pDest);
CopyMemory(pDest, pBuffer, cThis);
pSample->SetActualDataLength(cThis);
// time stamps indicate file position in bytes
LONGLONG tStart = pos;
LONGLONG tEnd = pos + cThis;
pSample->SetTime(&tStart, &tEnd);
hr = Deliver(pSample);
if (SUCCEEDED(hr))
{
pBuffer += cThis;
cBytes -= cThis;
pos += cThis;
}
}
}
}
return hr;
}
You have full source code, step it through with debugger until you reach the point where your filter calls IPin::Receive of the peer downstream filter, update/override code there and you have full control as for writing data into file etc.