BLE_NFC_SEC_PARAM_IO_CAPS

[Roei]

Hi,

Small question regarding BLE_NFC_SEC_PARAM_IO_CAPS.

I want my NRF application to advertise so my mobile will connect with passkey.

I need my mobile user to send the passkey which will be displayed on my device.

I'm trying to use BLE_GAP_IO_CAPS_KEYBOARD_DISPLAY, but the result is that the code is present on the mobile and the user has an option to confirm or cancel.

On the other hand - when I use BLE_GAP_IO_CAPS_DISPLAY_ONLY, I get the right result.

What is the reason for that?

Thanks!

[Amanda Hsieh]

Hi, 

BLE_GAP_IO_CAPS_DISPLAY_ONLY is Display Only.

BLE_GAP_IO_CAPS_KEYBOARD_DISPLAY is Keyboard and Display.

This depends on your device capabilities and application requirement. 

-Amanda H.

[Roei]

Is that possible that BLE_GAP_IO_CAPS_DISPLAY_ONLY provides a keyboard for insert passkey?

[Amanda Hsieh]

If you want Keyboard and Display, you should use BLE_GAP_IO_CAPS_KEYBOARD_DISPLAY.

-Amanda H.

[Roei]

The propose is keyboard and display on my nrf52840 device, or on my mobile?

[Amanda Hsieh]

Hi, 

The IO capability flags are used to specify how the user can interface with the peripheral. If the peripheral has a numerical keyboard a passkey can be used in the pairing process. The passkey is typically generated randomly and displayed on the Central device (Mobile), and the user has to enter the passkey on the Peripheral device. If the keys match, the pairing process succeeds.

Please see this post. 

-Amanda H.

[Roei]

If the passkey is inserted from the mobile, but displayed on the device (nrf52840), should I use BLE_GAP_IO_CAPS_DISPLAY_ONLY?

[Amanda Hsieh]

You don't need a physical keyboard and display when using 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.

-Amanda H.

[Roei]

I don't understand how, but when I define BLE_GAP_IO_CAPS_DISPLAY_ONLY, my nrf device displays the passkey and my mobile displays a keyboard to insert the passkey. Does it make sense? Even though I didn't use BLE_GAP_IO_CAPS_KEYBOARD_DISPLAY? I just want to make sure that I don't miss anything.

Thanks!

[Roei]

In other words - how does BLE_GAP_IO_CAPS_DISPLAY_ONLY suppose to affect the mobile?

[Amanda Hsieh]

Hi Roei,

Roei said:

when I define BLE_GAP_IO_CAPS_DISPLAY_ONLY, my nrf device displays the passkey and my mobile displays a keyboard to insert the passkey. Does it make sense?

 Yes, it makes sense. This defines the in/output capability of the device. In this case, the nrf does not have any input capability but the phone does. So the phone gets the responsibility for inputting the key. 

-Amanda H.