I am trying to read data from a serial device. It has an LED that turns on when I connect it to an actual serial port (on an old XP machine).
On my target machine however, I need to use a USB-serial adapter, and the LED does not turn on when connecting it.
It does turn on when I open the serial port with Putty or Hyperterminal though.
Now I have been trying to read it in my .Net project, and in order to do that, i run the example code from the MSDN documentation here :
https://msdn.microsoft.com/en-us/library/system.io.ports.serialport.readline%28v=vs.110%29.aspx
when I do, nothing gets read from the port, and the LED does not even turn on. I would expect it to turn on whenever I hit the
_serialPort.Open();
but it does not.
Is there a specific step, or configuration, or workaound, to ensure the serial port receives power when using USB adapters?
My serial device is a GlobalCaché GC-IRE.
The USB adapters I have been testing: 3 different ones, two no-names and one TrendNet TU-S9.
Related
I am trying to connect to a virtual com port provided by the drivers of a u-blox GPS device.
The device appears normally under the Sensors tab in Device Manager and I can really get the coordinate data using GeoCoordinateWatcher class from C#.
But I want to read the underlying NMEA data.
So in the process of doing that I installed the Virtual Com Port driver provided by U-BLOX and it generated a u-blox virta com port in devices manager.
Connecting to that using Putty is OK and I can see all the NMEA lines being dumped there.
but when I try to connect to the same port (after Putty is closed obviously) using C# I get the exception mentioned in the title
The given port name does not start with COM/com or does not resolve to
a valid serial port
My code is fairly simple (not the first time I use com ports) and everything is correctly defined (Port Name, Stop Bits, Parity, BaudRate etc). I even tried changing to a "wrong" com port name to see the exception I will get and it is completely different (Com Port does not a exit exception).
So what is happening with C# at this point? Am I doing something wrong? Is this a bug in the SerialPort class? Putty seems to work just fine in connecting and streaming the data.
My code is as simple as the following
m_port = new SerialPort
{
PortName = m_portName,
BaudRate = m_baudRate,
Parity = m_parityBit,
DataBits = m_dataBits,
StopBits = m_stopBit
};
m_port.Open();
I even tried hardcoding the values and I still get the same exception.
I tried many of the suggested solutions found here, none of them helped.
I also tried changing the COM port number from Device Manager advanced settings, that also did not help
As it turns out U-BLOX virtual COM port driver does not fully emulate a COM port which causes issues with .Net. Regardless if it is C# or C++ or any other language running on .Net
The only solution is to either, not use this device, or use an intermediary software.
If you don't have any particular reason for using the VCP driver, use the CDC driver instead. Available as "u-blox GNSS Standard Driver for Windows" at their website:
https://www.u-blox.com/en/product-resources/2673The/field_file_category/driver-221/field_file_products%253Afield_product_category/position-time-152
I had the same problem as you, but by changing the device driver, everything works as expected. It seems like their VCP driver is not fully compatible with the regular serial port driver structure.
I managed to resolve this issue, and thought I'd share my solution.
I wasn't able to use the CDC driver, as my device is a Rugged Windows Device with a dedicated GPS - the CDC solution may only work for removable gps devices via USB. The sensor driver must be installed, and the VCP driver can be installed alongside the sensor to provide a COM port.
Whilst the VCP driver does not fully emulate a COM port, you can use another piece of software to fully emulate the uBlox virtual com port and fill in the gaps. GPS Gate was that software for me - https://gpsgate.com/. The end result is uBlox Sensor -> uBlox VCP -> GPS Gate VCP. I was then able to successfully use the GPS Gate VCP in my C# app, and have GPS data coming down.
GPS Gate also offers a Location API plugin which could remove the uBlox VCP from the equation (uBlox Sensor -> GPS Gate VCP through Location API), but I didn't have much luck with it, plus I already had a working solution.
I have a device which sends data by com port on my computer.
I know how to simulate it, but the controller must be plugged in to simulate sending data (using Proteus)
Is it possible to simulate the com port sending data without having any external device plugged in?
For example: I want to write a C# program which opens the com port and waits for data, and another c# program which writes data on the same port.
The best way to do this is to use a software COM port emulator. I use com0com :
Null-modem emulator
This provides virtual NM COM port pairs on the system (ie: what is output to one is input to the other and vice-versa). The devices show up in Device Manager just like a real COM port so you interact with them in C# as though they were real hardware devices.
For simplicity's sake, get yourself a com port or null modem emulator. You'll get very far off track, and maybe waste a lot of time, trying to do this yourself.
See this post, too:
Faking an RS232 Serial Port
I have application to communication with device. Device is connected through serial COM port. My app can comunicate with device.
I need some method / event, that can scan COM ports through running app. When I'll connect device to PC - method / event will print MessageBox with message "connected", or something like that.
I found something like this:
comPort.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);
But it doesnt work.
I'm not sure if you are trying to auto-detect which port a device is connected to, or auto-detect whether a device is connected to a specific port.
In both cases though, the principle is the same:
you enumerate the the serial ports using: SerialPort.GetPortNames if you need to determine the port, or skip to the Step 2 if you already know the port
for each port in the collection you open a connection by creating a new SerialPort object for it, and by calling Open
for each open connection you attempt to write/read from the port the sequence of data that determines whether your device is attached
for each open connection if the data read times out then there is no device attached to the port; otherwise, if you get back what you expect you know your device is attached
for each port, close the connection using Close on the SerialPort object.
Performing the above at any given point will tell you whether your device is attached at that point, and which port it is attached to.
If you need to do presence detection continuously, then you will probably want to create a timer and perform this test periodically (every 30 seconds, or every 2 minutes - depending on the latency you are willing to accept).
NOTE
As others have indicated in the answers, you will want to run the serial port detection code asynchronously so as not to block your main application while scanning the ports. The scanning is guaranteed to take a while because of the time-outs of the ports that have no device attached.
In a C# application, what are some good ways to detect the presence of certain device connected to the computer? Programatically, of course. I need to support Windows XP and 7.
Background
I've been given a huge C# application that uses some connected device. The devices are custom hardware and are not designed to use without the software. When the C# app starts, it searches for such connected devices and communicates with them when appropriate. There can be more than one connected devices. I haven't looked into the source code that searches the devices. The devices are plugged into the PC with either USB or serial cable. They appear as COM port in device manager. Sometimes there can be USB hub or serial to USB converters in between the PC and the device.
When the device is connected with certain USB hub, or certain serial to USB converter is used, sometimes the software cannot detect the device properly. Sometimes it varies from PC to PC. We're not sure if it causes for some driver.
I'm told to look into the device searching algorithm and if possible, come up with better solution and replace current implementation. I haven't done this sort of task before and I need to learn how Windows manage the devices under the hood.
How can I search for specific connected devices in C#? What are some good practice and what I should be aware of or avoid?
You can find all devices in registry: HKLM/CurrentControlSet/Enum ( http://msdn.microsoft.com/en-us/library/windows/hardware/ff546173(v=vs.85).aspx )
But there will be problem with serial port. You can't be certain in which device is connected to a serial port. It can be mobile phone, modem, mouse, your device, another custom device, etc. To guarantee that it is your device connected to a given serial port you must try to communicate with it. And if it responds in proper way - then yes, it is your device.
Because of this many programs that works with serial devices asks user to manually select serial port, where device is connected.
UPD:
Another link about enumerating serial ports: http://social.msdn.microsoft.com/Forums/en-US/netfxbcl/thread/afb62e84-53e5-4f17-ba91-8de15c4c2e38/
I have a device connected to a host computer through cradle usb. Now, I'm just wondering if I could use C# sockets to communicate with the device (ie device sending data, host computer processing it then replying back to the device). How can I accomplish this? by that, what ip address etc etc.. do I have to change so that it would connect cause I have the sockets working on wireless. If not, then is there a way to connect to the device, open and read a file (a text document to be more specific) from the device to my host application.. any ideas?
Thanks! :)
Depending on your target device, when you connect via ActiveSync it likely makes a local RNDIS network connection between teh two devices. You can resolve "ppp_peer" as the partner's network name instead of trying to use a hard-coded IP address (IIRC the IP is different on XP than on Vista).
Be aware that it's not a full connection. TCP packets gets passed through, but things like ICMP do not.
Of course, this just gives you a socket connection, just like if you were to connect between two PCs. It's not going to allow you to do file system operations unless you have an app on the other side listening for commands. If you want that type of thing, Microsoft provides the Remote API (RAPI) interface (wrapped in managed code here)for a lot of basic commands, and it can be extended (with C) to do anything you'd like.