connection issue with the mobile : Connection failed, status 0x66

[mayur9095]

I'm using pbap_client_demo example code 'esp32 wroom 32 board', program compiles and flashed successfully into the board, but at first when I tried to establish connection with my mobile with command : "a - establish PBAP connection to 40:44:FD:16:96:4C" it has sent the pairing request to my mobile, I have accepted pairing request and tick marked "allow contact and call logs access", but connection failed with the error described in the title. tried on my another mobile still got the same issue.
and the problem is recurring every time I try to connect my mobile from the device.

Environment: I'm using esp-idf extension for vs code. (v5.4.0)

Steps to reproduce the behavior:

1. Run example 'pbap_client_demo '
2. MCU ' esp32 wroom 32'
3. Connection to device 'realme 8 pro / oppo a3x'
4. Start action 'a - establish PBAP connection to 40:44:FD:16:96:4C'

log message :

I (405) main_task: Started on CPU0
I (408) main_task: Calling app_main()
I (424) uart: queue free spaces: 10
[-] Phonebook name 'pb'
[-] Phonebook folder 'telecom/pb'
[-] Phonebook path 'telecom/pb.vcf'
I (435) BTDM_INIT: BT controller compile version [20b459d]
I (439) BTDM_INIT: Bluetooth MAC: 34:5f:45:a8:41:8e
I (448) phy_init: phy_version 4840,02e0d70,Sep 2 2024,19:39:07
W (517) phy_init: saving new calibration data because of checksum failure, mode(0)
BTstack up and running at 34:5F:45:A8:41:8E

--- Bluetooth PBAP Client (HF) Test Console 34:5F:45:A8:41:8E ---
Phonebook: 'telecom/pb'
Phonebook path 'telecom/pb.vcf'

a - establish PBAP connection to 40:44:FD:16:96:4C
A - disconnect PBAP connection to 40:44:FD:16:96:4C
b - select SIM1
r - set path to '/telecom'
R - set path to '/SIM1/telecom'
u - set path to 'telecom/pb'
v - set vCardSelector to N and TEL
V - set vCardSelectorOperator to AND
e - select phonebook 'pb'
f - select phonebook 'fav'
i - select phonebook 'ich'
o - select phonebook 'och'
m - select phonebook 'mch'
c - select phonebook 'cch'
s - select phonebook 'spd'
d - get size of 'telecom/pb.vcf'
g - pull phonebook 'telecom/pb.vcf'
h - pull vCard listing 'pb'
l - get owner vCard 0.vcf
j - Lookup contact with number '911'
t - disconnect HCI
p - authenticate using password '0000'
r - set path to 'telecom'
x - abort operation

[+] Connecting to 40:44:FD:16:96:4C...
[!] Connection failed, status 0x66

[mayur9095]

i have attached hci packet log with this comment. #/

hci_packet_log.txt

[mringwal]

Hi. You're trying to connect from the ESP32 to the phone. Phones will reject the connection if you didn't pair first. Please connect from the phone to ESP32 and if that works, you can try PBAP.
Actually, it looks like you've paired with this phone before, but have deleted the pairing on the phone. If you connect from phone, a new pairing should start.

[mayur9095]

Hi. i have tried exactly what you said.
added these three lines in main function to make device advertise itself so i can connect to it from my mobile :
// Make device discoverable and connectable
gap_discoverable_control(1); // Enable discoverable mode
gap_connectable_control(1); // Enable connectable mode
gap_set_local_name("ESP32_PBAP_Client"); // Set the device name

now device is discoverable, but whenever im trying to pair device from my mobile, device is not being paired and doesnt show up in paired devices list. and connection gets closed with :
[00:01:43.966] LOG -- hci.c.1284: Connection closed: handle 0x81, 40:44:FD:16:96:4C
[00:01:43.976] LOG -- hci.c.8232: BTSTACK_EVENT_NR_CONNECTIONS_CHANGED 0

i have attached hci packet logs below.

hci_packet_log_1.txt

[mringwal]

Please convert the text log into a .pklg file with btstack/tool/create_packet_log.py. You can then open it with Wireshark.
The log shows a connection request for SDP which BTstack rejects - which is weird as SDP is always needed/provided.
Please try again with the example code from our repo.