HOW to use direct advertising to connect the central successfully?

[liu_zhixiang]

I use nrf52832 board by fast advertising to connect the central(surface 4 Tablet).Then the board go to sleep.when I push the button the board use direct advertising to connect the central again,but it dont connect. I use the peer manager to get the central address,when the BLE_ADV_EVT_PEER_ADDR_REQUEST event of direct advertising happens.

SDK 14.2  Softdevice 132 .Can you give me some suggestions about direct advertising to connect previous central successfully.

[liu_zhixiang]

when first time  push button ,the board can connect the central by direct advertising.In connection state, application handles things completely, then the board and central disconnect .The board go to sleep. Next time(push button no matter how many times) the board can use direct advertising ,but cannt connect.I'm confused about this problem,How to solve this problem?

[Kenneth]

Hi, can you make sure that you first delete all bonds on the central and peripheral? 

[liu_zhixiang]

I use sniffer to catch logs again.It seems CINTIQ tablet don't have database discovery before direct advertisement.The log just like above nrf52_CINTIQ.But ,they can reconnect with direct adv.

I catch surface 4 and nrf52 again.nrf52_surface4.pcapng

They have database discovery before direct advertisement.But,have many info of "Encrypted packet decrypted incorrectly(bad MIC)".They cannt reconnect with direct adv.

I hope you can see something unusual. Thanks.

[Kenneth]

We do have a Surface 3 Pro (i5), can I use that one to recreate it here? If not, what Surface should I get?

Best regards,
Kenneth

[liu_zhixiang]

Yeah,you can program nrf52 board with official example  of ble_app_hids_keyboard,then connect to Surface 3.You can see the log I upload.when push butoon1 long time ,The nrf52 board disconnect the Surface 3.Then via direct adv,fast and slow adv with whitelist,but cant reconnect again.

[Kenneth]

Hi, I am not able to recreate it here. I have used attached main.c, I bonded with Surface 3, then I turned OFF and ON Bluetooth on Surface 3. The keyboard example would then reconnect immediately. Attached main.c file, maybe you can modify it so it fails?

\nRF5_SDK_15.0.0_a53641a\examples\ble_peripheral\ble_app_hids_keyboard

main.c

[liu_zhixiang]

Hi,I follow your steps to do it.First time, they can reconnect.But second time cannt reconnect.Then they cannt reconnect anymore. I mentioned that above.First time they can successed,but next cant.

In my project,I change main.c.Maybe,you can use my project recreate it with surface 3.But,there is another problem.It seems the nrf52's current is bigger than I think.When button pushing,the max current has 24mA.

[Kenneth]

Can you try my main.c and my description:

"I bonded with Surface 3, then I turned OFF and ON Bluetooth on Surface 3. The keyboard example would then reconnect immediately."

[liu_zhixiang]

I want you  to reconect they more than 2 times. If you turned OFF and ON Bluetooth on Surface 3 at second time,you will find they cannt reconnect. That's what's happening on my side.I use official example,not change anything.

[Kenneth]

In my case it re-connect immediately no matter how many times I turn OFF and ON Bluetooth on Surface 3. I am using Win8.1, are you using Win10?

[liu_zhixiang]

Yes.Windows 10 Home . Release 1709 . OS Internal version 16299.431

[liu_zhixiang]

Hi. Peripheral's address type is BLE_GAP_ADDR_TYPE_RANDOM_STATIC .Central's address type is BLE_GAP_ADDR_TYPE_PUBLIC . Does this matter?