Bluetooth - Paired but can't connect

[daveozzz]

Maybe try the connect using the bt.sh command and see if there are any error messages. First make sure the Bluetooth pairing agent is turned On in Audio Config.

Code:

pi@rp1:~ $ sudo /var/www/command/bt.sh -h
** BlueMoode version 1.5
**
** Usage: bt.sh [OPTION]
** -i initialize/reset controller
** -s scan and trust devices
** -l list discovered devices
** -p list paired devices
** -c list connected devices
** -d disconnect device <MAC addr>
** -r remove paired device <MAC addr>
** -P pair with device <MAC addr>
** -C connect to device <MAC addr>
** -D disconnect all devices
** -R remove all pairings
** -h help

ETA: Actually bt.sh is not needed since the connect is initiated on the phone. The other utilities that can be used to try and see Bluetooth error messages are below. I have no idea how to interpret btmon output though.

Code:

sudo systemctl status bluetooth

pi@rp1:~ $ btmon
Bluetooth monitor ver 5.50

Thanks I tried bt.sh anyway - the device is visible, paired, and bt.sh claims it has connected successfully ("device XX:XX:XX:XX connected") when asked (bt.sh -C), but then doesn't appear in the list of connected devices.
This is similar to what I see when trying to connect from the phone. It appears to think it has worked, but it drops off the "connected" list straight away.

I wish I knew more about bluetooth that I could give some more info on the issue.

The phone connects happily to an array of bluetooth devices (none of which are a RPi4 though)