README

Qrcode USBCom Reader

Example of using Datalogic QD2500 qrcode usb qrcode reader in Delphi-7 and C# while supporting unicode and single shout read. This examples implemented event based or call back function and Delphi7/Gui used and read thread to prevent GUI locking.

How to use in Delphi-7

1. Import UUSBCom.pas to your project. Then use UUSBCom in your file.

   pascalCopy

   uses ... , UUSBCom;

2. Define a data receiver procedure callback function:

   pascalCopy

   procedure  TForm1.DataReceived(const Data: string);
   var
   ExtractedData: TExtractedData;
   begin
       ExtractedData := ExtractDataUsingPerlRegEx(Data);
       Memo1.Text:=(Data);
   end;

3. Create USBCome instance and pass callback to it , Then start reader by calling StartReading():

   pascalCopy

   var
       USBCom : TUSBCom;
   begin
       ...
       USBCom := TUSBCom.Create(DataReceived);
       ...
   end;

   * You can pass port name like 'Com1' and baud rate to StartReading(Port: string = ''; BaudRate: DWORD = 9600). Otherwise it automatically choose last available com port and 9600 baud rate.

4. Make sure destroy object and release the com port when your work was down :

USBCom.Free();

More If you going to use this unit to extract data from qrcode text. Import PerlRegEx/pcre.pas , PerlRegEx/PerlRegEx.pas , UStringUtils.pas. Then ExtractDataUsingPerlRegEx() use for data extracting data from string. Change regular expressions relative to pattern. If you are dealing with arabic / persian unicode text use UTF8ToWindows1256AndConvertNumbers to convert utf8 string back to windows-1256 encoding which is compatible with Delphi 7.