ESP32 Forum

Posted: **Wed Oct 30, 2019 2:11 pm**

Hi,

I'm using the ESP32 WROOM 32D module, using it to connect two devices over Bluetooth.

When I have ACL connection to both of them, I try to open SCO connection. And I can only open one. When trying to open the second one, the controller will respond with HCI ERROR: 0x0A (Max Number Of SCO Connections To A Device)

It doesn't matter which device I connect, the first one will succeed and second will respond with this.
When trying to open the second SCO from other device, it will also not allow.

I have: CONFIG_BTDM_CONTROLLER_BR_EDR_MAX_SYNC_CONN=3
all that stuff.

BT Lib is on commit 'bugfix btdm sleep twice after wakeup request (6f423b2)' from 27.7.2019
I use v3.3-rc from 4.8.2019

Did anyone check ESP32 can support multiple SCO connection?
How can I debug it further?

Thanks.

Posted: **Tue Nov 05, 2019 6:52 am**

Solved it.

I'm not sure if its a bug or not, however ESP32 BT controller will not allow to open 2XACL & 2XSCO(HV3) channels. However it will allow to open the SCO channels when EV3 or EV5 packets are selected.

Posted: **Tue Apr 21, 2020 3:07 am**

Does this problem resolved? I meet the same question.After I configed the SCO packet type to EV3,it still can't create the second SCO wth the same error.

Posted: **Thu May 09, 2024 6:09 am**

I have the same problem as yours and your solution didn't solve my problem however my problem doesn't happen with all mobile phones it happens with some and others work properly if you have a solution please share it with us.

ESP32 Forum

[BT] Can't open more than one SCO.

[BT] Can't open more than one SCO.

Re: [BT] Can't open more than one SCO.

Re: [BT] Can't open more than one SCO.

Re: [BT] Can't open more than one SCO.