WinCe comport access

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picstart:
As a newbie to lazarus I had bit of a heavy lift to get comports working
for winCE if there is a better way then maybe someone could add their expertise

Background
MSDN WinCE3.0 API has the detailed info on the calls Ex SetupComm
plus the predefined structures EX DCB or COMMTIMEOUTS

Here is a skeleton for accessing a comport
1) the basic set up
uses
  Classes,Windows,WinCEint, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
  StdCtrls, ExtCtrls, Menus;
const
MAXSIZE=1024;
MAXTIMERCYCLES=30;
type
   PCHAR16=array [0..MAXSIZE] of Widechar;
   PCHAR8=array[0..MAXSIZE] of char;

public
   { public declarations }
  end;

var
  Form1: TForm1;
  MyCommhandle: Thandle;
  MyCommDCB:TDCB;
  MyCommtimeout:TCOMMTIMEOUTS;
  MyCommPort:PWideChar;
  MyInbuffsize,MyOutbuffsize:DWORD;
  MyBytesTrans:DWORD;
  MyCount:DWORD;
  MyBuffer:PCHAR8;
Success:Boolean;
2) the calls to set up the commport file ex Com1
   MyCommPort:='COM1:'; //// don't forget the colon
   MyCommhandle:=INVALID_HANDLE_VALUE;
   MyCommhandle:=CreateFileW(Pwchar(MyCommPort),GENERIC_READ or GENERIC_WRITE,0,nil,
   OPEN_EXISTING,FILE_FLAG_OVERLAPPED,0);
   Assuming MyCommhandle<> INVALID_HANDLE_VALUE you can proceed to step3
3)
   Myinbuffsize:=1024;
   Myoutbuffsize:=1024;
   Success:=SetupComm(MyCommhandle,MyInbuffsize,MyOutbuffsize);
assuming succes proceed to step4
4)
  now retrieve the current ports DCB ( this is needed to get MycommDCB fully populated
   Success:=GetCommState(MyCommhandle,MyCommDCB);
  assuming success proceed to step5
5)
   MyCommDCB.BaudRate:=4800; //// ex of setting baud rate other values in the DCB can also be assigned
   Success:=SetCommState(MyCommhandle,MyCommFDCB);
   assuming success proceed to step6
6) MyCommtimeout.ReadIntervalTimeout:=MAXDWORD;
   MyCommtimeout.ReadTotalTimeoutMultiplier:=100;
   MyCommtimeout.ReadTotalTimeoutConstant:=100;
   MyCommtimeout.WriteTotalTimeoutMultiplier:=MAXDWORD;
   MyCommtimeout.WriteTotalTimeoutConstant:=100;
   Success:=SetCommTimeouts(MyCommhandle,MyCommtimeout);
   assuming success proceed to step7
7) Now for read write
   Success:=readFile(MyCommhandle,MyBuffer,MyCount,MyBytesTrans,nil);
   Success:=WriteFile(MyCommhandle,MyBuffer,MyCount,MyBytesTrans,nil);
   Mybuffer is where you want to send or receive data and Mycount is the bytes you want
   MyBytesTrans is what the interface actually did transfer
8)
   CloseHandle(MyCommhandle)

donalejo:
Thanks, Question

How do I show the data in a label?

Ñuño_Martínez:

--- Quote from: donalejo on February 08, 2018, 06:33:25 pm ---Thanks, Question

How do I show the data in a label?

--- End quote ---

Using TLabel's "Caption" property. Just assign the value to it (as STRING, of course).

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