Perform Reset on USB Connectivity adapter causes Serial port to change on Ubuntu

[thin_ice]

I have Nordic NRF 52840 DK development board, using Ubuntu 18.04, I loaded "ble_connectivity_s140_usb_hci_pca10056" to the board successfully. Then I powered cycle and cannot get it to connect to Bluetooth Low engergy app whatsoever:

2:54:36.765

Validating connectivity firmware for device with serial number DAE038DE778D...

12:54:36.778

Connectivity firmware is valid.

12:54:36.779

Connectivity firmware version: ble-connectivity 0.1.0+Aug-14-2018-15-12-51. SoftDevice API version: 3. Baud rate: 1000000.

12:54:36.779

Opening adapter connected to /dev/ttyACM0

12:54:37.292

Successfully opened /dev/ttyACM0. Baud rate: 1000000. Flow control: none. Parity: none.

12:54:37.294

Reset performed on adapter /dev/ttyACM0

12:54:37.294

Received status with code 5 IO_RESOURCES_UNAVAILABLE, message: 'UART implementation failed while reading bytes from UART port /dev/ttyACM0.'

12:54:37.468

Device closed.

The issue is every time the software initializes the connection a reset is performed, this changes the UART port back and forth from ttyACM0 to ttyACM1 so the next step it tried to read will fail. This issue also exists with the nrf52840 Dongle but for the dongle I just unplug it every time and it seemed fine. But I cannot do that trick with the DK kit.

[Sigurd]

You are building the connectivity firmware yourself?

For nRF Connect Bluetooth Low Energy App, I would recommend using the connectivity .hex that the app prompts you to flash:

Here is the .hex the current version of BLE app will prompt you to flash for the nRF52840-DK:

connectivity_1.2.3_1m_with_s132_3.1.hex

And then you use the J2 USB connector on the short side of the DK.