How to set static passkey between two nrf52832 ?

[jenkey.zhu]

hello,ereryone!One nrf52832 as ble_central,and another nrf52832 as ble_peripheral. and the ble_peripheral (nrf52832 )set static passkey:

#define SEC_PARAM_BOND 1
#define SEC_PARAM_MITM 1
#define SEC_PARAM_IO_CAPABILITIES BLE_GAP_IO_CAPS_DISPLAY_ONLY
#define SEC_PARAM_OOB 0
#define SEC_PARAM_MIN_KEY_SIZE 7
#define SEC_PARAM_MAX_KEY_SIZE 16

static ble_gap_sec_params_t sec_params;

static void static_passkey_pair_init(void)
{
    uint32_t err_code;
    sec_params.bond         = SEC_PARAM_BOND;
    sec_params.mitm         = SEC_PARAM_MITM;
    sec_params.io_caps      = SEC_PARAM_IO_CAPABILITIES;
    sec_params.oob          = SEC_PARAM_OOB;
    sec_params.min_key_size = SEC_PARAM_MIN_KEY_SIZE;
    sec_params.max_key_size = SEC_PARAM_MAX_KEY_SIZE;
    static uint8_t passkey[]="123456";
    static ble_opt_t m_ble_opt;
    m_ble_opt.gap_opt.passkey.p_passkey = &passkey[0];   
    
    err_code = sd_ble_opt_set(BLE_GAP_OPT_PASSKEY,&m_ble_opt);
    APP_ERROR_CHECK(err_code);
}

How the ble_central (nrf52832 )need to set?

[Petter Myhre]

The central must use BLE_GAP_IO_CAPS_KEYBOARD_ONLY or BLE_GAP_IO_CAPS_KEYBOARD_DISPLAY.

Other than that nothing special. The central doesn't know that the passkey is static.

[jenkey.zhu]

Thanks Petter,but in fact the central has no keyboard and display,how the central get the static key?

[Petter Myhre]

You don't need a physical keyboard and display when using static passkey, but you still have to use BLE_GAP_IO_CAPS_KEYBOARD_ONLY or BLE_GAP_IO_CAPS_KEYBOARD_DISPLAY. Then when you get the BLE_GAP_EVT_AUTH_KEY_REQUEST event just reply with the static passkey. See this MSC for more information.