Secure GATTS server, can I have the client device enter the passkey?

[chris1seto]

I have a secure gatts server. I'm having a hard time understanding exactly how the security model works. Specifically, I want my client device to send a passkey to the server to authenticate the connection. The idea is that the ESP32 has a screen attached to it, so that when pairing is attempted, the passkey is generated on the ESP32 and displayed on the screen. The mobile phone user needs to look at the screen and enter the passkey as shown. Is this a supported mechanism?

I've only been able to get the GATTS server to work when the passkey is generated on the esp32, but then send to the phone and displayed for user confirmation. That doesn't work for me because I am trying to prohibit pairing without the user being able to see the screen physically.

Thanks

[chris1seto]

Nevermind, I see now. It's the ESP_IO_CAP_OUT IO capability option. This works!