https://devzone.nordicsemi.com/f/nordic-q-a/32612/start-program-when-gpio-input-is-set-nrf51-dongleHi We are trying a Nrf51-Dongle in a school prosject here in Norway We need to use one of the GPIO pins on the Nrf51-dongle as input When this input is 1 , we want the dongle to run the beacon program for sending notification to cellphone We havingen-USTelligent Community 13Thu, 22 Mar 2018 08:24:23 GMThttps://devzone.nordicsemi.com/thread/125461?ContentTypeID=1Thu, 22 Mar 2018 08:24:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:32bbad7a-6547-40ae-b0d1-584f68d53cdeJ&#248;rgen Holmefjord<p>Hi,</p> <p>Are you working on mbed, or using our <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk/keydef/PLUGINS_ROOT/com.nordic.infocenter.sdk5.v12.3.0/index.html?cp=4_0_5">nRF5 SDK</a>? There are multiple ways to achieve the functionality you want, but the simples might be to use <a href="http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.1.pdf#page=70">GPIOTE</a> to detect rising or falling edges on the GPIO, and call the softdevice functions for <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s130.api.v2.0.1/group___b_l_e___g_a_p___f_u_n_c_t_i_o_n_s.html#gaa88eea8e9e95dd96a7633e2c62f3ce16">stopping</a>&nbsp;and <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s130.api.v2.0.1/group___b_l_e___g_a_p___f_u_n_c_t_i_o_n_s.html#gab82c978db30188c7f4fbf2dac1d97720">starting</a>&nbsp;advertising in the interrupt handler. You can find an example of how to detect pin changes in <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v12.3.0/pin_change_int_example.html?cp=4_0_5_4_5_16">this example</a>.</p> <p>Best regards,<br />Jørgen</p><div style="clear:both;"></div>