Serial IO in VisualStudio 2011 / C++
I needed to hack together a quick windows application to read data over a serial port and write it to a file. Unfortunately I think VisualStudio is probably still the best way of writing Win32 GUI apps. However I’ve not really used VisualStudio since the VisualStudio.net beta, and most of the stuff I did before that was on VisualStudio 6.
Man Microsoft have really murdered C++… are these proprietary garbage collection extensions all over the place? I couldn’t see a way of writing a pure C++, unmanaged GUI app in VS 2011…
Anyway, to get Serial IO working in a GUI application I needed to add the following methods, these were all added to the Form itself, like I say this was a quick hack:
public:
// members
String^ comport;
String^ dump_filepath;
String^ current_filename;
SerialPort^ serialn;
// initalise serial port
void init_acquire() {
int baudRate=9600;
serialn = gcnew SerialPort(comport, baudRate);
serialn->ReadTimeout = 50;
serialn->Open();
}
// Read from serial port
String^ acquire() {;
String^ s;
try {
s = serialn->ReadLine();
}
catch (TimeoutException ^) { }
return s;
}
// Button handler, starts thread
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
dumped_lines = 0;
dumped_file_count = 0;
dump_filepath = this->drop_location_textbox->Text;
current_filename = dump_filepath + dumped_file_count + ".txt";
comport = comport_textbox->Text;
ThreadStart ^myThreadDelegate = gcnew ThreadStart(this, &Form1::repeat);
trd = gcnew Thread(myThreadDelegate);
trd->IsBackground = true;
trd->Start();
dumped_lines = 0;
}
// Thread code
delegate void DelegateThreadTask();
private: void ThreadTask() {
// This weirdness is required because setting the TextBox text is not thread safe.
if (data_textbox->InvokeRequired == false) {
String ^data = acquire();
this->data_textbox->Text = this->data_textbox->Text + data;
//current_filename
StreamWriter^ sw = gcnew StreamWriter(current_filename,true);
sw->WriteLine(data);
sw->Close();
} else {
DelegateThreadTask ^myThreadDelegate = gcnew DelegateThreadTask(this,&Form1::ThreadTask);
this->Invoke(myThreadDelegate);
}
}
// Thread loop (reads from serial, dumps to file/textbox.
private: void repeat() {
init_acquire();
while(true) {
ThreadTask();
Thread::Sleep(100);
}
}
You’ll also need to add the following headers:
using namespace System::IO::Ports; using namespace System::Threading; using namespace System::IO;
RSS