We need to interface with the payment terminal kernel to implement the interface for our payment terminals.
We have a terminal made by a manufacturer called AMP. They provide us all the documentation to their kernel. We have created an APP that will interface to the BLE chip on this terminal, and also provide an interface that can interact with mobiles to read payment information that they send. We have also developed an EMV compliant tap and go transit solution that works by tapping a card on our terminal that we read and send to our gateway. All of this has been done in C.