Hello,
Your search for the program for raspberry pi is over here as i am having an vast experience in these technology also i have already work on the POS system.
I can help you to connect the retailer pos printer to itself and capture the receipt data (from a serial port) and save them as a plain text or JSON object.
We have strong knowledge of C# , ASP.NET , MVC , WebApi , Angularjs, WPF , HTML5, CSS, Javascript , Jquery , SQL SERVER .
Professional Certification: Microsoft Certified Developer and HTML5 CSS3 JavaScript Technical Skills: ASP.NET (2.0, 3.5,4.0 and 4.5) / C# / SQL SERVER (2008,2012,2014) / CSS / AJAX Silverlight / MVC.
I am here to communicate with you in your time zone and i assure you that you will get your work in very professional way with me. Message me so we can discuss more about your project requirement.
Thanks