I made bluetooth cnnection nrf51kit and nRFconnectapp in phone with the example.I dont know how app works and I want to exchange data between app-nrf through keil.How can I do that,which example in keil_v5 should I use?

[mert]

[endnode]

I would suggest to start first with "I dont know how app works" and get through nRF5 Getting Started section, possibly also through Tutorials on this page.

[mert]

These tutorials doesnt say anything about how to use this nrfconnect application. I need a solid example about how I can send data to this app.

[endnode]

Sounds to me like you are looking for someone who will develop the solution based on your requirements, so more recruitment question then technical one for this forum;) nRF Connect can act as both GAP Central and Peripheral (depending on underlying Android or iOS API and HW capabilities), the same applies to GATT Server and Client roles, but as a tool it's generic app. If you want something specific for bidirectional data transfer then Nordic UART Service (NUS) examples are the right thing for you. Thee are two examples in nRF5 SDK (GAP Peripheral and Central) and there is mobile app in Play Store which knows the protocol and you should be able to connect to nRF5x device running that example FW and retrieve some data from it (if it sends any;).

[Wojtek]

There indeed are lots of people on this forum, that could make firmware for You for monies, if you want to achieve your goal without learning effort.