Bluetooth chip: Broadcom 4339
UART port: UART2
L4T version: L4T_21_5
Use the following command to scan bluetooth device ok.
hcitool scan
But the following command to send files. The TK1 hangs and reboot.
Do you have a serial console cable? If so, then you might try to post a log of whatever you can from dmesg. Also, after reboot, see if there is a note about the crash from the previous boot’s log file “/var/log/kern.log.1” or one of the dmesg logs (e.g., check the current kern.log, kern.log.1, dmesg, dmesg.0, syslog, syslog.1).
Without more information it will be difficult for anyone to be able to say anything. Any additional information on the chip/hardware/wiring might help.