RE: Peripheral disconnected ，Disconnected, reason 40

Sigurd — Wed, 04 Nov 2020 16:54:58 GMT

Hi,

Try increasing the connection interval, and see if that helps. If you are using the scanner module to connect, and not setting any other values when you call nrf_ble_scan_init(), then increase the value of NRF_BLE_SCAN_MIN_CONNECTION_INTERVAL and NRF_BLE_SCAN_MAX_CONNECTION_INTERVAL in sdk_config.h

We have a unofficial multilink version of the ble_app_uart_c here, https://github.com/NordicPlayground/nrf52-ble-app-uart-c-multilink ,you might find that useful.

RE: Peripheral disconnected ，Disconnected, reason 40

see you Monkey King — Sat, 17 Oct 2020 01:22:13 GMT

hi Sigurd✈

Thank you for your answer. I tried to change

#define SLAVE_LATENCY 2

gap_conn_params.slave_latency = SLAVE_LATENCY;

#ifndef NRF_BLE_SCAN_SCAN_INTERVAL
#define NRF_BLE_SCAN_SCAN_INTERVAL 375
#endif

#ifndef NRF_BLE_SCAN_SCAN_WINDOW
#define NRF_BLE_SCAN_SCAN_WINDOW 80
#endif

But it doesn't help. Instead, it's more error reporting 0x8.。What else could I do?

0> <debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x8.
0> <debug> nrf_ble_gatt: Updating data length to 251 on connection 0x8.
0> <info> app: MAC: 736AE5563478
0> <info> app: Peripheral connected
0> <info> app: m_conn_handle 0x8
0> <debug> nrf_ble_gatt: ATT MTU updated to 247 bytes on connection 0x8 (response).
0> <info> app: ATT MTU exchange completed.
0> <info> app: Ble NUS max data length set to 0xF4(244)
0> <debug> nrf_ble_gatt: Data length updated to 251 on connection 0x8.
0> <debug> nrf_ble_gatt: max_rx_octets: 27
0> <debug> nrf_ble_gatt: max_tx_octets: 251
0> <debug> nrf_ble_gatt: max_rx_time: 328
0> <debug> nrf_ble_gatt: max_tx_time: 2120
0> <debug> app: PHY update request.
0> <info> app: Fast advertising.
0> <info> app: Peripheral disconnected
0> <info> app: Disconnected, reason 8
0>
0> <debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x8.
0> <debug> nrf_ble_gatt: Updating data length to 251 on connection 0x8.
0> <info> app: MAC: 736AE5563478
0> <info> app: Peripheral connected
0> <info> app: m_conn_handle 0x8
0> <debug> nrf_ble_gatt: ATT MTU updated to 247 bytes on connection 0x8 (response).
0> <info> app: ATT MTU exchange completed.
0> <info> app: Ble NUS max data length set to 0xF4(244)
0> <debug> nrf_ble_gatt: Data length updated to 251 on connection 0x8.
0> <debug> nrf_ble_gatt: max_rx_octets: 27
0> <debug> nrf_ble_gatt: max_tx_octets: 251
0> <debug> nrf_ble_gatt: max_rx_time: 328
0> <debug> nrf_ble_gatt: max_tx_time: 2120
0> <debug> app: PHY update request.
0> <info> app: Fast advertising.
0> <info> app: Peripheral disconnected
0> <info> app: Disconnected, reason 8

Best regards.

RE: Peripheral disconnected ，Disconnected, reason 40

Sigurd — Fri, 16 Oct 2020 13:21:08 GMT

Hi,

Disconnect reason 40 in hex is 0x28, that points to;

#define BLE_HCI_INSTANT_PASSED 0x28 /**< Instant Passed. */

What I suspect is the problem is that a link layer procedure is started, some of these procedures assume that a change should occur in a instant after 6 connection intervals + slave latency. If the peer/link is somehow blocked during this complete period (e.g. due to scanning and/or flash erase operations), then the instant might have passed. You could try to adjust the scanning window/interval, increase connection interval, and/or maybe try slave latency=2 for the peripheral link.