Error code 520 implies Connection Timeout indicating link supervision timeout or syncronization timeout. Is this issue seen with only one device ? Can you switch the phone to some other device and check ?

What happens if you use nimble's bleprph/ blecent example, do they work ?

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I would check and confirm the io capability being set. If it is being set to NoInputNoOutput, then pairing will not use passkey entry mechanism.

Does setting own_addr_type as BLE_OWN_ADDR_RPA_RANDOM_DEFAULT in bleprph example here helps ?

When I use the jump to symbol tool in the menuconfig editor, it returns "no results" for BLE_STORE_MAX_CSFCS, BLE_STORE_CONFIG_PERSIST, or BLE_STORE_MAX_BONDS.

BLE_STORE_MAX_CSFCS and BLE_STORE_MAX_BONDS : Both are driven by menu config macro: BT_NIMBLE_MAX_BONDS
BLE_STORE_CONFIG_PERSIST ...

These are configurable from menuconfig. They have some default predefined values ( i.e. it is not 0 )

Hi,

.att_flags = BLE_GATT_CHR_F_READ


This is incorrect in descriptor.

Plesae instead use .att_flags = BLE_ATT_F_READ , and try

> My issue is that I can't make them to work side by side.

Can you elaborate on what is working or not working in more detail , so someone may have inputs .

There is a BT_NIMBLE_HOST_ALLOW_CONNECT_WITH_SCAN configuration, which allows scanning and connection happen at same time. May be you can try ...

> At this point, the question is: is it normal on Iphone that an ESP32 BLE device is not seen when I activate the discovery function?

Yes, this is specific to iphone where it searches certain specific adv pattern to show up device in the bluetooth settings screen.

You can try the hid device ...