nrf52dk connection fails for central sample

[Mark G.]

Hi all,

I am currently testing on nrf52dk (PCA10040, 3.0.0) with NCS v3.3. Note: I also tested with vanilla Zephyr and see the same issue.

The code I run is to 100% the central sample from: "samples/bluetooth/central" with default nrf52dk/nrf52832 board setting.

with the following proj.conf:

CONFIG_USE_SEGGER_RTT=y
CONFIG_LOG_BACKEND_RTT=y
CONFIG_LOG_MODE_DEFERRED=y
CONFIG_LOG=y

CONFIG_BT=y
CONFIG_BT_CENTRAL=y

I have the issue that some connection attempts get closed immediately:

Connected: CC:6B:3E:7F:02:B8 (random)
[00:00:04.350,341] <wrn> bt_conn: conn 0x20001c98 failed to establish. RF noise?
Disconnected: CC:6B:3E:7F:02:B8 (random), reason 0x3e

I have multiple peripheral devices that I need to connect to. Some devices work perfectly, some specific ones fail all the time with the error above. It seems these device behave a little different then others. What would be the proper way to investigate these issues and how could we make the connection more robust?

[Simonr]

Hi

Okay, how many devices are connected to the central device when you start seeing these issues? What are CONFIG_BT_MAX_CONN and CONFIG_BT_MAX_PAIRED set to in your central application? Applications will fail if you have reached the maximum number of allowed connected devices for the application.

Best regards,

Simon