how can I test range of bluetooth with my mobile ( android 4.8 ) and nRF25840 dev kit?

[Gót G?y]

as the tittle. I have a nrf52840 kit and I want to see it's bluetooth on my mobile. what is the example can help me?

[endnode]

Hi, you can probably start with flashing some o BLE Peripheral examples from nRF5 SDK v13 to your PCA10056 board (nRF52840 Preview DK), downloading Nordic nRF Connect app to your mobile and observing the broadcasts. If this work then simply run as long as you see some signal;) As next step you can play with Tx Power of the broadcasts (typically requires recompiling of the BLE FW for nRF52 target), you can also establish connection link and try its reliability (seeing broadcasts here and there is little bit different situation then reliable connection link with some reasonable throughput). Overall hard to say what such tests could tell you on top of one hour of reading the internet but hands-on experience is sometimes needed!

[Gót G?y]

thanks for your comment. I did as your tutorial. I now I want to know how MCU dectect if I press button. ( mechanism of event and handler ). Which document can hepl me ?

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BSP example from nRF5 SDK is probably what are you looking for... (there are some button press features in many other SDK examples indeed, it's basic input technique for embeded applications;)