Is this a component that comes with some kind of serial interface, or is it a simple button matrix - and if so, is it multiplexed? Please be as specific as possible - the more specific you are, the easier it is for us to help you. Depending on your answer to the above question, but you can likely use the GPIOTE peripheral for this. A simple demonstration of the GPIOTE peripheral's usage is given in the Pin Change on Interrupt example from the SDK.
With this information I would then suggest that you take the working code that you have made for the peripheral blinky example and merge it into the BLE blinky example. It is easier to merge non-BLE parts into a BLE example than going the other way around.
Please elaborate on what you have done, in detail, so that I may try to help you resolve the issue.
What have you tried? What did you observe? How did it differ from what you would have expected? Was there any errors generated? If so, which, and from where? The more information you provide, the easier it will be for us to help you resolve your issue.
