I have done something similar to this with a USB scanner connected to a Windows laptop. The scanner was an input device, like the keyboard. When I was in a text box on a page, using the scanner placed the barcode value into the box. You can buy barcode scanners on Amazon for not much ($15 or so). If you got a scanner, I think it would work with a text field in your Mendix app without too much work.
I second Mike’s idea here. I have successfully used an NFC reader to read in multiple NFC cards. I used on change events to register if a new chip was read. Worked pretty well with board functionality, too