error(0x3D) Disconnected, reason 61 sdk12.3

[Mr.Wu]

I test ble bond with 'ble_app_gls' in sdk 12.3.0

eg.nRF5_SDK_12.3.0_d7731ad\examples\ble_peripheral\ble_app_gls\pca10028\s130\arm5_no_packs

my phone is meizu mx4, android 5.1, another one is coolpad 8690, android 4.4.2, test app is nRF Connect, board is pca10028.

On communication with Android device sometimes the link disconnects with disconnection reason61(0x3D) - BLE_HCI_CONN_TERMINATED_DUE_TO_MIC_FAILURE.

who can help me? thanks!

[Petter Myhre]

BLE_HCI_CONN_TERMINATED_DUE_TO_MIC_FAILURE occurs when in an encrypted link there is a packet with correct CRC but wrong MIC. This should only happen when the key used for encryption is wrong.

When does it happen? The first time you connect and bond? Or later if you disconnect, reconnect and re-encrypt the link?

[Seth Foster]

This is happening to me on specifically a Moto G with android 7.1. I see message sequences that look like this:

[003837-1951]  NRF   BLE event: 0x10: BLE_GAP_EVT_CONNECTED
[003837-000]  NRF   Initial conn params: interval 39 timeout 2000
[003839-002]  NRF   BLE set to connected
[003873-034]  NRF   BLE event: 0x1C: BLE_GAP_EVT_RSSI_CHANGED -54
[003971-098]  NRF   BLE event: 0x11: BLE_GAP_EVT_DISCONNECTED
[003971-000]  NRF   NRF: Disconnected: 61

(The first three lines are from the single connected event, the two last lines are from the single disconnected event). I am printing out every softdevice BLE event. At no point am I attempting bonding or even simple pairing.

[Hung Bui]

@seth: Please capture a sniffer trace. . Do you have this issue all the time or seldom ?

Do you have the same problem when testing with an example in the SDK ? the ble_app_hrs for example ?

[Seth Foster]

Ah I ended up solving the problem as documented in this separate devzone question, the problem was I needed to hold off on conn param negotiation until the connection was more established.

[Hung Bui]

Thanks Seth. I assume the stack on the phone was expecting to do service discovery before it can handle parameter update request.