JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You can use our QR Codes widget: http://widgets.jotform.com/search/qr.
Here's how to add a widget in your form: http://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form.
Or, you can use an external barcode generator, get the image file and you can upload and display it in the form using our image field (Form Tools section).