BLE Uart example hangs

RE: BLE Uart example hangs

MartinBL — Thu, 15 Mar 2018 13:46:56 GMT

The BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED define is not meant to be changed. It is defined in ble_gap.h:

#define BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED  0 /**< Unlimited advertising in general discoverable mode. */

If you don't want your advertiser to time out you set the advertising timeout to zero.

RE: BLE Uart example hangs

pktron — Thu, 15 Mar 2018 10:00:27 GMT

But where to change BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED ?

RE: BLE Uart example hangs

Primož Kralj — Thu, 03 Dec 2015 13:31:22 GMT

I am no expert, but isn't 180s the default advertisement timeout for the example? After that nRF51 goes to deep sleep and starts advertising again when you wake it up (on the DevKit one button is assigned as WAKEUP). Without this timeout the battery would drain fairly quickly.

RE: BLE Uart example hangs

Rob Jansen — Thu, 03 Dec 2015 13:21:29 GMT

I'm pretty sure I found the answer on this.

In on_ble_evt() I found a switch with the following case:

 case BLE_GAP_EVT_TIMEOUT:
        if (p_ble_evt->evt.gap_evt.params.timeout.src  == BLE_GAP_TIMEOUT_SRC_ADVERTISEMENT)
        { 
            nrf_gpio_pin_clear(ADVERTISING_LED_PIN_NO);

            // Configure buttons with sense level low as wakeup source.
            nrf_gpio_cfg_sense_input(WAKEUP_BUTTON_PIN,
                                     BUTTON_PULL,
                                     NRF_GPIO_PIN_SENSE_LOW);
            
            // Go to system-off mode (this function will not return; wakeup will cause a reset)
            err_code = sd_power_system_off();    
            APP_ERROR_CHECK(err_code);
        }
        break;

and the timeout is set to 180s, which is indeed the time at which the application hangs and waits for the button to be pushed. Setting this timeout to BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED fixes my problem. The application now runs forever.

I found it a bit strange to set this 180s timeout in this type of a demo application but for low energy purposes it kind of does make sense.