When adding new items to Inventory, you can use barcode readers.
You have to enable this feature in Settings / Syst. settings / Inventory / General (item central_store_adding_by_barcode).
You can use any reader that can be configured to do exactly what you want.
The device should allow you to set what will happen after the code is read. It is important because it will allow you to prevent the form from being sent off. Instead, you will be able to read further codes.