RS-232 Only Able To Read In Data That Changes Constantly?
May 5, 2011
I am working on a project that reads in data from a device. I am able to read in the constantly changing data only, i need to be able to read in the saved data that is in the device as well.
My question is if the data that is saved in a certain type and i only read try to read it in as text for example, will the saved data I am looking for not be displayed?
ex: im trying to read in text but my device has the data saved in hex, do i see anything or nothing?
idk if this helps or matters but the rs-232 connection is a null modem and im working with VB 2010
I have a DataTable that's constantly being updated with new data from my database via a timer. That data is eventually reformatted and displayed in a DataGridView control.In an effort to prevent the DataGridView from completely refreshing from re-databinding (thus, clearing out selections, resetting scrollbars, defaulting sorting settings, and making the gridview flash as it reupdates), I'm simply removing old rows from the datagrid that no longer exist in the DataTable, and adding new rows to the datagrid that appear in the DataTable since the last update.
For the sake of simplicity, we'll call DataGridView the LEFT table, and DataTable the RIGHT table I'm looking for a way to go through both tables (LEFT and RIGHT), and remove old rows that are no longer in RIGHT and delete them from LEFT. And look for new items in RIGHT and add them to LEFT. Each table has a column called "RecID" containing a unique id for each entry that can be used for comparison. is there a way to do this all in one loop? What I'm looking for, in pseudo code:
<loop through everything> if RecID does not exist in LEFT but exists in RIGHT add new item to LEFT if RecID does exist in LEFT but does not exist in RIGHT
Ive been working recently on a chat. Ive been using FTP to comunicate through both forms but it need to constantly download the new data and make the application freeze. Even with a Backgroundworker. So my question is : is there a way to keep a constant connection between the form and the host? And not LAN ,I mean that doesnt need to be on the same router.
I have created several small applications that use my own DLL. The problem is, this DLL is constantly changing. My current solution to this problem is that I have a Setup project in the class library solution that creates and registers the DLL. In all my applications I then have to open the solution and re-reference the newly created/registered DLL. Then I have to re-compile their setup projects, uninstall the old applications, and then re-install the new application.
There has to be a better way and I'm just not sure because I'm fairly new to all this. I have looked into ClickOnce but I don't think that will solve my issue as I cannot publish a class library. I have looked into checking version numbers but I must be doing something wrong because it doesn't work either.I understand that once a DLL is created and being used in an application it should essentially not be touched. I do not have that option in this situation. It is constantly updated. Done.
Edit: The DLL is not constantly changing during runtime but it is constantly evolving to allow more functionality and detail within the other applications. Also, one big thing I guess I should have mentioned is the Public interface is constantly chaning - usually adding new methods.
I have built a web browser and my new window function is working great, it allows me to open popups that use normal https links without a hassle. But I am having some problems when the links contain java code (like the one below:
The reason why this operation fails because the string that is being passed to the Navigate method is not an actual URL.It is apiece of Javascript code which needs Javascript engine to process it firstly. Apparently, Webbrowser.Navigate() does not have this functionality,so it fails. If you simply put the string in IE�s address bar and press enter, IE will also not able to open it. The reason why it does work if you access the HTML page in IE and click the hype link is because this will make IE to use Javascript engine to process the code.
Since the API(Webbrowser.Navigate) does not have the functionality to process Javascript code,build up my own code to process the string which you get by using the GetAttribute method. The code reads the string and finds the actual URL and passes it to the Navigate method.
The only problem is that the javascript code constantly changes (varies upon what link is opening) and the url itself will change depending on what the link is linking to! Below is the code that I use at the moment to get the full link .finding the actual URL in the javascript even with the javascript differing from link to link).
Dim myElement As HtmlElement = CType(TabControl1.SelectedTab.Controls.Item(0), WebBrowser).Document.ActiveElement Dim address As String = myElement.GetAttribute("href")
I've project where i wanna check if user is connected to internet if he isn't then form must close and another form should show up ! Problem i'm getting is i can't use check it constantly, even if i use while loop
keep looping the following code until condition is wrong or until connection is made While IsConnectionAvailable() = False ' code goes here for when connection to hotflask can't be made[code].....
but here form 2 keep showing up and it crashes system, is there any simple way to do it .
I have a stream reader that reads a website text and places it in a txt file synonyms.txt then I can read to a specific line in the textfile that the results always end up on and place that line in a richtextbox in my project.the line looks something like this:
\tab\tab\tab\tab <br /><div class="ResultsSubTitle">Synonyms (Grouped by Similarity of Meaning) of <span class="Accent I">verb</span> house</div><br /><div class="Accent Sense">Sense 1:</div>house<br /><span class="equals">accommodate, hold, admit</span><br
So I have been trying to make this game in visual basic, it is basically like the worlds hardest game but in viusal basic but I am having problems programming the enemy, it doesn't seem to move up and down or left and right at all.
This is an annoying issue that started less than a week ago and couldn't come at a worse time, as I have a major project deadline to meet. At least once every TEN minutes, the program crashes with the error "Microsoft Visual Studio has stopped working" -- it only occurs when I am writing/editing code while execution is paused (Edit and Continue), which I do all the time since I am stepping through rather complex subroutines line-by-line. I literally have trained myself to save after each line of code I write, delete, or change, so thankfully I never lose much, if anything, when I restart, but it is irritating and time-consuming having to set up everything in the program and get to the place in the code that I was before. I have installed VS 2010 SP1, tried deleting the .suo file, and a few other supposed fixes that I came across online, to no avail.[code]...
In my program, I have a condition I need to constantly check for. When my program gives an error, I change a label to a different text, lets say "fail" for now. I'm trying to make a condition where the program constantly checks for the label change to "fail" from the start of the program. I am having trouble trying to get this to work.
Im working on a HSD 32 bit data bus to serial converter via a microcontroller. Now first I want to make a sort of data sniffer to read the data bus (32Bit) .All on the controller side is working and the stream of bytes are coming in via RS232 as 4 bytes in HEX like FD,A5,45,8B . I already converted the bytes in Dec and ASCII to determine what is passed true the bus and how fast and stuff.. Now that is all correct and working very well if the LSB (least significant bit) of the 32 data bus is Data line 0 and the MSB (most significant bit) is Data line 31 but if that is not the case I need to invert the 32Bits (like as I would invert the connector on the bus) . How do I best do this using the 4 bytes I send from the micro controller.
Example:
(MSB) 01001000 01100101 01101100 01110000 (LSB) HEX= 48 65 6C 70 DEC= 72,101,108,112 ASCII= H E L P
I have the following code for a gradient form below. When I step through my code it seems to fire constantly. Does this mean that it fires constantly at run-time? If so, is there a way to stop it from firing constantly
Private Sub Form1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint Dim Mybrush As New System.Drawing.Drawing2D.LinearGradientBrush(Me.ClientRectangle, Color.LightSkyBlue, _ Color.Snow, Drawing2D.LinearGradientMode.Vertical) e.Graphics.FillRectangle(Mybrush, Me.ClientRectangle) End Sub
I am using creating a server/client style program, and it uses tcp connections.Now, the server is like this, but it will only listen until it has received its one request. My issue lies in the fact that it only listens till it receives the one message, then closes. The bigger issue, though, is the lag, it will not let me interact with the form in any way until it closes the connection. Is there a way to make it "passively" listen, for lack of a better word? I do not want it to take up tons of cpu.
I am navigating to a web page and when I programicly click a button to go to the next page that next page is constantly refreshing over and over.Is there anyway to stop the page from refreshing constantly?
I was getting some slightly unusual behavior when using the mouse wheel for some zooming/scaling work (only vaguely related to the earlier thread, for those who remember it). Frankly, it is likely that I have a bug in some code, but that wasn't quite enough to explain what I was seeing. Therefore, I used a error logging feature in my app to note the delta being passed in each Mouse Wheel event. I then ran the app and gave the wheel one good spin, which was about the maximum that I would normally ever spin the wheel in one steady, continuous motion. I wasn't going slow, I wasn't going fast, and I rotated it about as much as my finger comfortably could in a single roll.[code]I then rolled it back the other way using the same motion, and got 8 events, mostly under 200, but one of them was -331 and the other was -7940.
After a handful of tests, it appears that the wheel event is raised often, which is no surprise, but that the values fluctuate all over the place. With a continuous rotation, or as nearly continuous as I can make it, I can see a series of events with one of them easily being ten times the rest.The problem this presents is that the scaling I am using is not smooth (nor is it standard mathematical scaling, but that's a different story). Each zoom level doubles the size of the objects relative to the previous level, though the distance between them stays the same. I would like to do this by dividing the delta by some factor, and if that is above a threshold, increase the zoom level. That won't work smoothly, in this case. If I make the factor something small enough that I pick up a small rotation, then any larger rotation is likely to include a delta that takes the screen through all zoom levels in a single step. Alternatively, if I make the factor large, then all smaller rotations are simply ignored.One option would be to filter out rotation values below 200 and above 800, or so. I am looking for other alternatives.
im developing an application that constantly checks a particular webpage for changes in the page. im using the webbrowser.documenttext to read changes in the source, its working great. until when i tried to use webbrowser.refresh(), an ugly popup that says. "To display the webpage again, Internet Explorer needs to resend the information you've previously submitted.If you were making a purchase, you should click Cancel to avoid a duplicate transaction. Otherwise, click Retry to display the webpage again."
dim reader as new streamreader("txt.txt") dim placeholder as integer = 0 dim line as string
[Code].....
this checks my file for any position with latdif < 30, I want this to be on a timer but I want it not to open the text file everytime is this possible?
I made a little application that check the servers and if the servers go off for more than 5 mins then the program will sent me a mail.My problem is how do I compare the server date time witch display in a textbox to the real datetime which display in a label also how do I run the program constantly till the user decides to exit by clicking on a exit button.
I have a windows form where I want the time to constantly be updated. Right now it will take the current time from when the program was started.
For example, if I started the program at 4:30:29 PM that is what it will show the whole time the program runs.I need it to constantly be updated as the seconds tick by. So, If I started the program at 4:30:29 PM and ran it for exactly 5 minutes, the time displayed then should be 4:35:29 PM.The data being taken in and saved needs a time associated with it and the end user also need to know the current time as the program is ran in full-screen. [code]...
I have a fairly simple XML file that I just want to read the data from.
It has 3 levels, root, main section and items. There are no attributes. I want to go to the first main section by name, then read in all the items. The items all are named the same. I've seen this done before, so it should be ok. No writing will be done. Basically this is a static data file
I'm only getting started with VB.Net, using VB Express 2008.Using the System.Data.SQLite wrapper, I need to read data off a SQLite database file, and chart data using basic bars, pies, lines, etc. Nothing fancy.
That code works to read the entry data and to recognise the correct data, and the incorrect. However, even if entry is correct, the error msgbox will appear (x times of how many records there are in file), despite being navigated to the menu. Anyway that the Else isn't triggered when data is correct. Also for it to appear just one instead of (x times of how many records there are in file.)
I am trying to make a voice recognition thing with google's voice api.I modified UPLOADFILEEX function that can be found on codeproject.The file I wish to delete is C:ecord.flac Here is the function below
Public Shared Function UploadFile(ByVal uploadfilename As String, ByVal url As String, ByVal fileFormName As String, ByVal contenttype As String, ByVal querystring As System.Collections.Specialized.NameValueCollection, ByVal cookies As CookieContainer) As String If (fileFormName Is Nothing) OrElse (fileFormName.Length = 0) Then fileFormName = "file"
i have a embedded device that send data through PC over USB communication.i want to accept those parameters and using those parameters plot a graph(for example plot a graph over "x-axis" and "y-axis".Can any help me how to create such aplication using visual basic.
i would like to know how to read the USB data through VB. so far my project is like this, DAQ using PIC18F4550 and the data will interface with PC. In PIC part, i make it sending data in every second as ideal. i would like to use VB to collect the data and view the data in graph form. 2 type data will be collected. 1st data will be voltage versus time (analog data). 2nd data will be time using versus n-times (digital data).
