I have disabled EAN13 validation in OpenERP product page. I have comment the line from /addons/products/product.py:
_constraints = [(_check_ean_key, 'You provided an invalid "EAN13 Barcode" reference.
Now I can enter any type of barcode and associate it with a product.
The problem is: when I use the barcode scanner to scan a non EAN13 barcode, the system doesn't recognize at the POS frontend. I understand it might has something to do with the device.js file, however, I'm not sure from where I start.
As a note, it has been reported that several scanners take care of the conversion from a certain barcode type to another barcode type (eg. from UPC to EAN13) themselves. It is then much easier to configure a scanner to convert a type into another one than to modify the source of OpenERP to get a new barcode type to be recognized and handled.