Could you please attach a btmon log of the attach procedure?
On one shell run “sudo btmon”
On another shell then run: “sudo btattach -B /dev/ttyACM0 -S 1000000”
And then attach the log output from btmon in an email or paste service.
Also, have you tried “sudo btmgmt --index 0”? i.e. specifying the index when invoking btmgmt?
From: devel@... <devel@...>
On Behalf Of Cale Collins
I have built and installed HCI_UART to nRF52840 Nordic Development kit. When I connect this device it appears with "lsusb", seemingly I can attach it using "btattach -B /dev/ttyACM0 -S 1000000", revealing hci0. I have made the recommended adaptation to "/lib/systemd/system/bluetooth.service", appending -E to the "ExecStart=/usr/lib/bluetooth/bluetoothd -E" line.
When issuing commands with "btmgmt", "btmon" reports "Invalid Index (0x11)". Normal HCI commands fail such as "hciconfig hci0 up".
Using Bionic-Beaver Ubuntu, 4.15 kernel, Bluez 5.48, also tested with Xenial Ubuntu 4.15 kernel, Bluez 5.50. Any suggestions would be greatly appreciated.