Hi i am a embedded system engineer from 7 years i am working with only POS machine , i did coding of all the projects in QT c++ and 8 pos devices which is having linux based , android based , windows based .i worked on kernal level changing and writing shell script and sensors interfacing through usb ports , I have a more experience with all types of smartcards (contact and contact less ) SCOSTA cards ,ISO1443 A/B , memory cars , mfire cards etc ...
Thank you