Keyboard example failure in sending keys after power-cycle with Android KitKat

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

Susheel Nuguru — Tue, 03 Jul 2018 07:55:53 GMT

Hi Kim,

I have compared your logs and I only found two differences between working and not-working logs

Not-working device does an LLCP feature exchange where as on working, there is no LLCP feature exchange.
On working the notification is reached to the slave the second time it is connected, but on not working your button press is not visible in air, so for some reason, with notWorking phone, when you press the button, it is not sending notification. I do not know why.

I am not sure but it could be because of the incompatibility of some vendors able to support the value of 0 for WinOffset in the connect request parameter. Try the below code while initializing softdevice

ble_opt_t ble_opt;
memset(&ble_opt, 0, sizeof(ble_opt));

ble_opt.gap_opt.compat_mode_1.enable = 1;

err_code = sd_ble_opt_set(BLE_GAP_OPT_COMPAT_MODE_2,&ble_opt); 
APP_ERROR_CHECK(err_code);

The documentation for that can be found here

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

MJin — Tue, 03 Jul 2018 05:37:03 GMT

Hello Nordic,

We got a support from local channel FAE.
Their opinion is that KitKat seems to be wrong.
The logs with Ellisys analyzer were attatched.
Could you help us what the problem is?

Sincerely yours,

devzone.nordicsemi.com/.../test-logs.zip

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

Susheel Nuguru — Thu, 21 Jun 2018 10:34:53 GMT

Your log is showing only the data packets and seems like it cannot be filtered based on protocol. I cannot debug it since to do that i need to decode each and every data packet. I am not an expert in wireshark, but there must be a way where your output log will allow me to filter packets based on protocol (for example, L2CAP or HCI etc)

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

MJin — Thu, 21 Jun 2018 03:46:04 GMT

Hello Aryan

It took a time getting a log.

Hear are logs with normal Window10 and strange KitKat 4.4.2.

Please give me a tip why nRF52 could not send "hello" in second connection.

Sincerely yours,

nRF52DK MAC: 81:bd:6a:a1:59:c1
Win10 BT MAC: B0-35-9F-81-D6-83
KitKat 4.4.2 BT MAC: BC:72:B1:CF:C5:56 <-- Not visible in logdevzone.nordicsemi.com/.../8688.2018.6.18-nRF-Sniffer-Test.zip

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

Susheel Nuguru — Wed, 13 Jun 2018 11:59:30 GMT

kitkat is quite old and it is very likely that the ble stack on the phone with kitkat probably has some bugs. errors like this are easily pinpointed if you get some sniffer log of the BLE traffic from these devices.

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

MJin — Thu, 07 Jun 2018 06:54:46 GMT

If you test "nRF5_SDK_14.2.0_17b948a\examples\ble_peripheral\ble_app_hids_keyboard" with KitKat, you can see it.

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

MJin — Thu, 07 Jun 2018 06:52:56 GMT

1. sd_ble_gatts_hvx() returns NRF_ERROR_INVALID_STATE when connection is okey, there is no BLE_GAP_EVT_DISCONNECTED event.

2. I've compared to Android KitKat and others(windows 10)

In KitKat, BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST event was not received.

What Should I check?, please help me.

-----------------------------------------------------------------------------------------------------------------------------------

Following is a dump trace of "nRF5_SDK_14.2.0_17b948a\examples\ble_peripheral\ble_app_hids_keyboard"

I Added a trace in nrf_ble_gatt_on_ble_evt() like this

void nrf_ble_gatt_on_ble_evt(ble_evt_t const * p_ble_evt, void * p_context)
{
nrf_ble_gatt_t * p_gatt = (nrf_ble_gatt_t *)p_context;
uint16_t conn_handle = p_ble_evt->evt.common_evt.conn_handle;

if (conn_handle >= NRF_BLE_GATT_LINK_COUNT)
{
return;
}

NRF_LOG_INFO("[%s:%d] p_ble_evt->header.evt_id: 0x%02x", __func__, __LINE__, p_ble_evt->header.evt_id);

switch (p_ble_evt->header.evt_id)
{
case BLE_GAP_EVT_CONNECTED:
NRF_LOG_INFO("BLE_GAP_EVT_CONNECTED");
on_connected_evt(p_gatt, p_ble_evt);
break;

case BLE_GAP_EVT_DISCONNECTED:
NRF_LOG_INFO("BLE_GAP_EVT_DISCONNECTED");
on_disconnected_evt(p_gatt, p_ble_evt);
break;

------------------------------------------------------------------------------------------------------------------------------

1. Windows 10 after power-cycle

0> <info> app: HID Keyboard example started.
0> <debug> app: pm_whitelist_get returns 1 addr in whitelist and 1 irk whitelist
0> <info> app: Fast advertising with whitelist.
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x10
0> <info> ble_gatt: BLE_GAP_EVT_CONNECTED
0> <info> app: Connected to a previously bonded device.
0> <info> app: [on_connect:105] p_hids->conn_handle : 0
0> <info> app: Connected
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x23
0> <info> ble_gatt: BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST
0> <debug> ble_gatt: Peer on connection 0x0 requested a data length of 251 bytes.
0> <debug> ble_gatt: Updating data length to 27 bytes on connection 0x0.
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x24
0> <info> ble_gatt: BLE_GAP_EVT_DATA_LENGTH_UPDATE
0> <debug> ble_gatt: Data length updated to 27 on connection 0x0.
0> <debug> ble_gatt: max_rx_octets: 27
0> <debug> ble_gatt: max_tx_octets: 27
0> <debug> ble_gatt: max_rx_time: 328
0> <debug> ble_gatt: max_tx_time: 328
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x14
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x1A
0> <info> app: Connection secured: role: 1, conn_handle: 0x0, procedure: 0.
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x55
0> <info> ble_gatt: BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST
0> <debug> ble_gatt: Peer on connection 0x0 requested an ATT MTU of 525 bytes.
0> <debug> ble_gatt: Updating ATT MTU to 23 bytes (desired: 23) on connection 0x0.
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x50
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57
0> <info> ble_gatt: [nrf_ble_gatt_on_ble_evt:499] p_ble_evt->header.evt_id: 0x57

///////////////////////////////////////////////////////////////////////////////////////////////////////

2. KitKat 4.4.2 after power-cycle

RE: Keyboard example failure in sending keys after power-cycle with Android KitKat

Susheel Nuguru — Tue, 05 Jun 2018 13:30:22 GMT

hvx will return invalid state error if there is no connection. Can you please make sure that you are calling hvx while you are still in connection? It seems that there could be a disconnect event that has been ignored?