What is the reason of making nRF APIs that complicated?

[Jarmo]

As an example, let's see this function from app_hrm (heart rate monitor):

static void conn_params_init(void)
{
    uint32_t               err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = m_hrs.hrm_handles.cccd_handle;
    cp_init.disconnect_on_fail             = true;
    cp_init.evt_handler                    = NULL;
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}

Quickly looking, it seems that there's a lot of code doing lots of things. However, after reading out the lines it turns out that the information is mostly redundant (like "cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY"), and the function just bypasses parameters forward to another function. I used to see this type of coding at the beginning of 1990's, but it was quite soon replaced with much more comfortable way, using function parameters. With that style, the above code would shrink as follows:

ble_conn_params_init(
    NULL, FIRST_CONN_PARAMS_UPDATE_DELAY, NEXT_CONN_PARAMS_UPDATE_DELAY,
    MAX_CONN_PARAMS_UPDATE_COUNT, m_hrs.hrm_handles.cccd_handle, true, NULL,
    conn_params_error_handler);

And actually, the extra function definition conn_params_init() would no more be needed at all. This type of coding would make application much much more readable, yet it would save code lines and probably even flash space.

I have to say that your code looks much more complicated that it would need to be. I know this is a kind of "school of thought" issue, and maybe related to "linux-style" -coding. But still, your coding style doesn't make the APIs too easy for customers. Sorry to say, but it has been a horrendous experience to get familiar with nRF51822 SDK (and the DFU OTA is still not working, but that's another story).

[endnode]

(continue)

• You very much nailed it in your last remark. BLE chipset is not meant (and won't be until more advanced architectures such as ARM Cortex-Ax will achieve similar power budget, which will take another 5+ years) to host OS comparable with anything you quote (Symbian/Android/other embedded Linux or Windows clones). You might get closer with "embedded" systems such as Brillo but look at their requirements for hosting platform and try to ask Google if it will ever run on ARM Cortex-M processors (expect "U nuts?!" answer;).

Cheers Jan