What steps will reproduce the problem? 1.Is it support SCO? and how? 2. 3.

What is the expected output? What do you see instead?

What version of the product are you using? On what operating system?

Please provide any additional information below.

it does not support SCO - I never used it. I don't think the code for SCO would be much different than ACL (but how would I know). if you work on SCO, please let me know

Thank you reply so quickly. I want do handsfree ,it work on SCO ,so how can I make it work in btstack. Any tips ? Thanks.

look at the source code of BTstack. check out hci_transport.h and the hci_transport_uart.c implementation. Both miss SCO. That's the first step.