ble_uart example disconnect after 40 seconds while connected to raspberry-pie

[Ben]

Hi,

i have a problem when using the ble_uart connected to Raspberry-pie withe Bluez.

after 40 seconds the connection is lost.

tried to use several examples, but most of them has the same problem (with different disconnection times).

when used  ble_hrs example the connection is stable.

how can i fix this problem.

Thanks.

[Amanda Hsieh]

Hi Ben, 

Which version of the SDK you are using? Do you use nRF52840DK?

Could you provide the sniffer log and print the disconnect reason?

In ble_evt_handler, you could do something like this:

        case BLE_GAP_EVT_DISCONNECTED:
        
            NRF_LOG_INFO("Disconnected reason: %d.",p_ble_evt->evt.gap_evt.params.disconnected.reason);

-Amanda H.

[Ben]

Hi,

i am using SDK version 15.3 with Sorfdevice S140 V6.1.1

the sniffer result:

114	0.063	Slave	LE 1M	LE LL	0	150	0	1	FALSE	158	Empty PDU
115	0.064	Master	LE 1M	LE LL	0	48440	1	1	FALSE	159	Empty PDU
116	0.065	Slave	LE 1M	LE LL	0	150	1	0	FALSE	159	Empty PDU
117	0.065	Master	LE 1M	LE LL	0	48440	0	0	FALSE	160	Empty PDU
118	0.066	Slave	LE 1M	LE LL	0	150	0	1	FALSE	160	Empty PDU
119	0.067	Master	LE 1M	LE LL	0	48439	1	1	FALSE	161	Empty PDU
120	0.068	Slave	LE 1M	LE LL	0	150	1	0	FALSE	161	Empty PDU
121	0.069	9e:7b:ef:d1:15:e0	LE 1M	LE LL	35	49216				0	ADV_IND
122	0.071	9e:7b:ef:d1:15:e0	LE 1M	LE LL	35	360				0	ADV_IND
123	0.072	9e:7b:ef:d1:15:e0	LE 1M	LE LL	35	360				0	ADV_IND

i get Disconnect reason 0x8 and 0x22

Thanks.

[Amanda Hsieh]

Could you upload the sniff Wireshark log (.pcapng) file? Thanks. 

-Amanda H.

[Ben]

disconnect.pcapng

disconnect in number 1691

[Amanda Hsieh]

Hi Ben, 

0x08 is BLE_HCI_CONNECTION_TIMEOUT, and this happens because the supervision timeout is hit (no packets from the peer is received in x seconds).

0x22 is BLE_HCI_STATUS_CODE_LMP_RESPONSE_TIMEOUT which means that a link-layer procedure has timed out (data length negotiation for instance). The timeout is 40 seconds, so the easiest way to find out which procedure it was that timed is to get a sniffer trace and see what happened 40 seconds prior to the disconnect. 

Is this a custom board? Have you tried the same code on the nRF52 DK? Does it happen there? This post might help.

Or maybe you can try to the connection parameters in ble_hrs example: 

#define MIN_CONN_INTERVAL                   MSEC_TO_UNITS(400, UNIT_1_25_MS)        /**< Minimum acceptable connection interval (0.4 seconds). */
#define MAX_CONN_INTERVAL                   MSEC_TO_UNITS(650, UNIT_1_25_MS)        /**< Maximum acceptable connection interval (0.65 second). */

-Amanda H.