sd_ble_gap_rssi_get does not work

[Lezard]

HI,

We connect our own board with nrf51 via UART. From the host board, I call sd_ble_gap_rssi_start() first. I can see BLE_GAP_EVT_RSSI_CHANGED happens. Then I call sd_ble_gap_rssi_get(), but nothing happens. It seems the program blocks.

The following is my code:

static void on_connect(ble_evt_t *p_ble_evt)
{
    uint32_t ret;

    .......
    g_ble_context.conn_handle = p_ble_evt->evt.gap_evt.conn_handle;

    ret = sd_ble_gap_rssi_start(p_ble_evt->evt.gap_evt.conn_handle, 10, 0);
    if (ret) {
        ......
    }

    ret = sd_ble_gattc_primary_services_discover(p_ble_evt->evt.gap_evt.conn_handle, SRV_DISC_START_HANDLE, NULL);
    if (ret) {
        ......
    }
}

Then I call sd_ble_gap_rssi_get() after receiving BLE_GAP_EVT_RSSI_CHANGED event(I can see log of BLE_GAP_EVT_RSSI_CHANGED event).

int8_t rssi = 0;
sd_ble_gap_rssi_get(g_ble_context.conn_handle, &rssi);

This is the normal case. I also tried to call sd_ble_gap_rssi_get() without calling sd_ble_gap_rssi_start(). I think it should return error. Is it right? But it also blocked.

[Joakim Jakobsen]

Hi Lezard.
Hard to say what could be the issue. Maybe you could post some relevant code to help shed som light to the case?
Also, information about what device, Softdevice, SDK and what example that you are using is good practise to include in your question.
Best regards.

[Lezard]

We use nrf51822, s130, SDK9.0. We use our own host board to correct the nrf board via UART. In nrf board, we run the example ble_connectivity so that we can call softdevice api from host side. Current status is no matter how we call sd_ble_gap_rssi_get(), before or after sd_ble_gap_rssi_start() or even set a wrong connection handle, the program blocks and returns nothing.

[Joakim Jakobsen]

Where are you calling the rssi_start and rssi_get functions? Remember that the function sd_ble_gap_rssi_start() needs to be called to start reporting RSSI before calling the sd_ble_gap_rssi_get() function.
If you could edit your original post and insert the relevant parts of your code, it could be easier to find the problem.
You can also take a look at this thread, with a similar problem.
Best regards.

[Lezard]

I have already added the relevant code. Could you please check it? Thank you.

[Joakim Jakobsen]

Hi!
The sd_ble_gap_rssi_get() function should return an error if called before the sd_ble_gap_rssi_start().
As stated in the infocenter:
NRF_ERROR_NOT_FOUND will be returned until RSSI was sampled for the first time after calling sd_ble_gap_rssi_start.
Are you using the APP_ERROR_CHECK function to see if any errors is returned?
How are you trying to display the value returned by the rssi_get function?