Code examples

 		High Level Code generation in C, C++, Visual C++ VC6.0
1.1 the simplest RS232 only TX program


Create Your own MFC Dialog Project
Insert a EditControl and a Button
Add files serial.cpp and serial.h to your project


In the function OnInitDialog open the serial port
Adapt the variable iComPort to your port

If you have problems download the complete project
download source and EXE
The EXE is in the "Release" directory

1.2 RS232 only TX more sofisticated


add another button
add CR Carriage Return and LF Line Feed to the STRING
Send this string over RS232

If you have problems download the complete project
download source and EXE
The EXE is in the "Release" directory
1.3 RS232 RX and TX communication


Now we use also the receiver routine from serial.cpp

Press the RX-button and read the contents of RS232 RX buffer.
If you need a more sofistcated receiver routine have a look to the next program.

download source and EXE
1.4 RS232 serial communication in hex- and textmode



In this program you can change baudrate and toggle DTR and CTS line

download source and EXE

Compiled with Visual C++ 6.0
1.5 RS232 draw received bytes



this program can be usefull if you have an embedded board and this board sends
one byte data like a temperature or other.
you can test this program also with "1.6 send one byte every second"
download source and EXE

Compiled with Visual C++ 6.0
1.6 RS232 send one byte half (less or more) second



You can connect two serial ports together on your PC to test this program
with the program "1.5 draw received byte"
download source and exe

Compiled with Visual C++ 6.0
1.7 RS232 open COM1 COM2 COM3 COM4


download source and exe for this 1+4 windows
the first window is a dialog window (parent) with 4 kind dialog windows
IDD_COM1, IDD_COM2, IDD_COM3, IDD_COM4 

Serial4.cpp and Serial4.h
For every port we need a different handle

the kind windows needs 3 WM_MESSAGES:
 WM_INITDIALOG function OnInitDialog  (to start the timer)
 WM_TIMER      function OnTimer       (to read every 50 msec the COM port)
 WM_CLOSE      function OnClose        to kill the timer and to close COM port)


Compiled with Visual C++ 6.0
2 RS232 connected with a Modem

Send text data and receive text data from a modem.
download source with EXE
Compiled with Visual C++ 6.0 
void CRs232aDlg::OnTimer(UINT nIDEvent) 
{
unsigned char buf[500];
int xx,index;

  if(nIDEvent==1)
  {
   xx = ReadRs232Input(buf, COM1);
   if(xx)
   {
    index=0; 
    while(xx--)  m_strEditRead += buf[index++];
    UpdateData(false);
   }
  }
 CDialog::OnTimer(nIDEvent);
}

There is a periodically readout of the input buffer of RS232 with a TIMER-Function.
RS232 connected with a Modem

Send text data and receive text data from a modem with LF detect.
download source with EXE
Compiled with Visual C++ 6.0 
void CRs232aDlg::OnTimer(UINT nIDEvent) 
{
unsigned char buf[500];
int xx,index;

  if(nIDEvent==1)
  {
   xx = ReadRs232Input(buf, COM1);
   if(xx)
   {
   index=0;
   
    while(xx--) {  m_strEditRead   += buf[index];
                   RxBuffer[iRxIndex++] = buf[index];
                   if(buf[index] == LF) LineFeedDetected();
                   index++;
                }

   
        UpdateData(false);
   }
  }
 CDialog::OnTimer(nIDEvent);
}

void CRs232aDlg::LineFeedDetected()
{
CString str;
RxBuffer[iRxIndex]=0;  // end of string; now you can evaluate this string 
iRxIndex=0;

str.Format("LineFeed%c%c",CR,LF);
m_strEditRead += str;
}
There is a periodically readout of the input buffer of RS232 with a TIMER-Function.
In the function "LineFeedDetected()" you can evaluate the content of RxBuffer
RS232 Modem state_machine


download source with EXE
Compiled with Visual C++ 6.0

To control a Modem we need automatics steps. One solution is a state machine. This is an example with six states.
Send ATZ with CarriageReturn and LineFeed, the modem answers with ATZ CR LF followed with OK CR LF.
Every time we receive a LF the input string is checked.
  GSM-MODEM terminal program


download the EXE

download the complete C-sourcefiles

Compiled with Visual C++ 6.0
3 LPT: read and write to parallel port

download the EXE
download the driver GIVEIO.SYS

download the complete C-sourcefiles

Compiled with Visual C++ 6.0

The driver GIVEIO.SYS must be in the root directory c:\
to install this driver you must have administrator rigths
if you have an error in attempt to write to LPT restart the program
The output byte toggles only from 0xAA to 0x55
3.01 LPT: flashing light on parallel port

download the EXE and source
download the complete C-sourcefiles

Compiled with Visual C++ 6.0

The driver GIVEIO.SYS must be in the root directory c:\
to install this driver you must have administrator rigths

3.01 LPT: flashing light on parallel port

download the EXE and source
download the complete C-sourcefiles

Compiled with Visual C++ 6.0

The driver GIVEIO.SYS must be in the root directory c:\
to install this driver you must have administrator rigths

7 Exercises and training programs

Exercises to learn hex and binary arithmetic
The programs can print a DINA4 page with exercises without solutions,
Pressing the button “F” the solutions are displayed.
If you have 20 students the values for every student are different.
Try it out and give me a feedback.

You can download only the EXE or the complete source files
EXE-FILE: BITCHANGE.ZIP Sourcefile: bitchange.zip

EXE-FILE: BINHEX.ZIP Sourcefile: binhex.zip

Compiled with Visual C++ 6.0