Making your own barcode scanner is a formidable task. The ones I have seen have pretty powerful microcontrollers on them. (not 8051s) An industry barcode scanner has to be able to recognize several standard types of barcodes, inverted barcodes, etc. This has to be done with measuring the timing of the blinking of reflected light from a laser or LED and storing the timing information of the pulses of the light being on/off, and then figuring out what it means.
There are all the optical considerations: lenses, focusing, detecting...


There are OEM barcode scanner modules that you can hook up to the UART of a microcontroller. The microcontroller could be equipped with a flash that has voice tags and a database of barcode numbers that are associated with the voice tags, and it would respond when recognizing a barcode number from the scanner. It is possible to record/play short audio clips with an 8052 - I have seen it. You need plenty or RAM and Flash.

The OEM barcode scanner module will be about
100 dollars and a barcode pistol about 200+.
With only the scanner, you can piggyback your application and make your own "pistol" or whatever.

I could consider doing this, but I need the
parts and software. It will be a couple hundred dollars a unit in parts.

William