I am pretty sure that is where the RDY and WAIT commands come in to play. I modified the code from that thread and was able to get both Servos and Steppers to work using it.
SIZE=2FONT=Times New RomanCOLOR=#000000SEROUT 16, 16572,'RDY',10/COLOR/FONT/SIZE SIZE=2FONT=Times New RomanCOLOR=#000000SERIN 16,16572,15,timeout,WAIT('!' I don't have time right now for a complete answer but in the mean time think about using headers to seperate your data. Everything with a header is read as data everthing else is discarded, including the echo For example IF SerialInput = '1' THEN SEROUT 16, 16468, 'mydata',CR,'11.111', CR ELSEIF SerialInput = '2' THEN SEROUT 16, 16468, 'mydata',CR,'22.222', CR ELSEIF SerialInput = '3' THEN SEROUT 16, 16468, 'mydata',CR,'33.333', CR ENDIF VB looks for the 'mydata' header with ReadLine and knows the following string is valid data. In VB Readline looks for a string terminated with a Newline character which has a default value of 10, Carriage return has a value of 13. The default NewLine value can be modified in VB eg SerialPort1.NewLine=10 or SerialPort.NewLine=13 This means the default would be SEROUT 16, 16468, Changing to SerialPort.NewLine=13 would mean SEROUT 16, 16468, Jeff T. When you say that what you're sending to the BASIC Stamp module seems to be in your input buffer that makes complete sense.
The BASIC Stamp modules have a 4.7K resistor between their SIN/SOUT lines, which causes echo. So from the VB application perspective what you send you also receive. From the BASIC Stamp module perspective this never happens because the BASIC Stamps module does not have a serial buffer and since it can perform only one task at a time, all data sent is sent before you can SERIN and see it.
![]()
Note To view the.NET Framework source code for this type, see the. You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see. Use this class to control a serial port file resource. This class provides synchronous and event-driven I/O, access to pin and break states, and access to serial driver properties. Additionally, the functionality of this class can be wrapped in an internal object, accessible through the property, and passed to classes that wrap or use streams.
The SerialPort class supports the following encodings:, and any encoding defined in mscorlib.dll where the code page is less than 50000 or the code page is 54936. You can use alternate encodings, but you must use the or method and perform the encoding yourself.
![]()
You use the method to retrieve the valid ports for the current computer. If a SerialPort object becomes blocked during a read operation, do not abort the thread. Crack the sims 1 full expansion tank. Instead, either close the base stream or dispose of the SerialPort object.
![]()
Hi All, I am back playing with serial ports and stuff. I would like to know if there is an advantage (programatically) between the.ReadLine and.ReadExisiting functions of the SerialPort class. I have previously used the.ReadExisting (and built up a string which I then process) in the DataReceived event. I am able to specify on my device, the 'header' and 'footer' strings to send.
If I send a r n (new line) I can use the.ReadLine function. Recently I have seen that data coming from the device has been missing characters etc, and am wondering if it is because the thread which processes the DataReceived Event is still busy when more data is arriving. Is it better to use the ReadLine function? Does the ReadLine function clear the port's InBuffer when it is run, or do I still have to clear the buffer?
Oh and by the way, I am using vs2008. I've heard the the 3.x versions of the SerialPort class are riddled with problems, so am using the 2.0 framework for this particular project. I had faced problems using.ReadLine method, even i had some characters missing. Lately I tried using.ReadExisting method, which helped me receiving the entire data in a single event.
Roberto carlos pra sempre. But then i faced a problem with encoding, which i tried changing the encoding type & found the correct results. Similarly like you had some trouble with the threads as well, I introduced the Delay method (i.e.
Visual Basic Serial Port Programming
Thread.Sleep(1000)) which helped me solved the problem. ReadLine can be used if an end of line is expected, else ReadExisting is best for reading the entire data. Try having a Delay, hopefully u would have complete data. Following code i have written for you. Private Sub SerialPort1DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived 'This event will Receive the data from the selected COM port.
How to: Receive Strings From Serial Ports in Visual Basic. 2 minutes to read. Contributors. In this article This topic describes how to use My.Computer.Ports to receive strings from the computer's serial ports in Visual Basic. To receive strings from the serial port. Initialize the return string. Dim returnStr As String = '.
Determine which serial port should provide the strings. This example assumes it is COM1. Use the My.Computer.Ports.OpenSerialPort method to obtain a reference to the port. For more information, see. The Try.Catch.Finally block allows the application to close the serial port even if it generates an exception.
All code that manipulates the serial port should appear within this block. Dim com1 As IO.Ports.SerialPort = Nothing Try com1 = My.Computer.Ports.OpenSerialPort('COM1') com1.ReadTimeout = 10000 Catch ex As TimeoutException returnStr = 'Error: Serial Port read timed out.' Finally If com1 IsNot Nothing Then com1.Close End Try. Create a Do loop for reading lines of text until no more lines are available. Do Loop. Use the method to read the next available line of text from the serial port. Dim Incoming As String = com1.ReadLine.
Use an If statement to determine if the method returns Nothing (which means no more text is available). If it does return Nothing, exit the Do loop. If Incoming Is Nothing Then Exit Do End If.
Visual Basic Serial Port Communication
Add an Else block to the If statement to handle the case if the string is actually read. The block appends the string from the serial port to the return string. Else returnStr &= Incoming & vbCrLf. Return the string. Return returnStr Example Function ReceiveSerialData As String ' Receive strings from a serial port. Dim returnStr As String = ' Dim com1 As IO.Ports.SerialPort = Nothing Try com1 = My.Computer.Ports.OpenSerialPort('COM1') com1.ReadTimeout = 10000 Do Dim Incoming As String = com1.ReadLine If Incoming Is Nothing Then Exit Do Else returnStr &= Incoming & vbCrLf End If Loop Catch ex As TimeoutException returnStr = 'Error: Serial Port read timed out.' Finally If com1 IsNot Nothing Then com1.Close End Try Return returnStr End Function This code example is also available as an IntelliSense code snippet.
This web site may reference real estate listing(s) held by a brokerage firm other than the broker and/or agent who owns this website. Any information relating to a property referenced on this web site comes from CRMLS. The data contained herein is copyrighted by CRMLS and is protected by all applicable copyright laws.
![]() See More On MSDN
In the code snippet picker, it is located in Connectivity and Networking. For more information, see. Compiling the Code This example assumes the computer is using COM1. Robust Programming This example assumes the computer is using COM1. For more flexibility, the code should allow the user to select the desired serial port from a list of available ports.
For more information, see. This example uses a Try.Catch.Finally block to make sure that the application closes the port and to catch any timeout exceptions. For more information, see.
Comments are closed.
|
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |