zephyr/samples/bluetooth/peripheral_accept_list
Rubin Gerritsen a4e43d013c Bluetooth: Samples: Use string printing functions for error codes
When developing Bluetooth applications, you typically run into some errors.
If you are an experienced Bluetooth developer, you would typically know
how to translate the error codes into string representations.
Others might not.

This commit to adds string printing of error codes for all
samples to make them more user-friendly.

Several formatting alternatives were considered. The chosen alternative
balances code readability and FLASH size (with and without string
printing).

Example output from the peripheral_hids sample when the
peer rejects pairing:

```
Bluetooth initialized
Bluetooth authentication callbacks registered.
Advertising successfully started
Connected 5E:67:02:D3:1C:DB (random)
Security failed: 5E:67:02:D3:1C:DB (random) \
level 1 err 6 BT_SECURITY_ERR_PAIR_NOT_ALLOWED
Disconnected from 5E:67:02:D3:1C:DB (random), \
reason 0x13 BT_HCI_ERR_REMOTE_USER_TERM_CONN
```

Other alternatives that were considered:

- Use of parantheses:
```
// strings enabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 \
err BT_SECURITY_ERR_PAIR_NOT_ALLOWED(6)
Disconnected from 5E:67:02:D3:1C:DB (random), reason \
BT_HCI_ERR_REMOTE_USER_TERM_CONN(0x13)
// strings disabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 err (6)
Disconnected from 5E:67:02:D3:1C:DB (random), reason (0x13)
```

- Spaces and parantheses:
```
// strings enabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 \
err BT_SECURITY_ERR_PAIR_NOT_ALLOWED (6)
Disconnected from 5E:67:02:D3:1C:DB (random), \
reason BT_HCI_ERR_REMOTE_USER_TERM_CONN (0x13)
// strings disabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 err  (6)
Disconnected from 5E:67:02:D3:1C:DB (random), reason  (0x13)
```

- Parantheses around everything:
```
// strings enabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 \
err (BT_SECURITY_ERR_PAIR_NOT_ALLOWED(6))
Disconnected from 5E:67:02:D3:1C:DB (random), \
reason (BT_HCI_ERR_REMOTE_USER_TERM_CONN(0x13))
// strings disabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 err ((6))
Disconnected from 5E:67:02:D3:1C:DB (random), reason ((0x13))
```

- Error code first, then string representation:
```
// strings enabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 \
err 6 (BT_SECURITY_ERR_PAIR_NOT_ALLOWED)
Disconnected from 5E:67:02:D3:1C:DB (random), reason \
0x13 (BT_HCI_ERR_REMOTE_USER_TERM_CONN)
// strings disabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 err 6 ()
Disconnected from 5E:67:02:D3:1C:DB (random), reason 0x13 ()
```

- Apostrophes around error printing:
```
// strings enabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 \
err "BT_SECURITY_ERR_PAIR_NOT_ALLOWED (6)"
Disconnected from 5E:67:02:D3:1C:DB (random), reason \
"BT_HCI_ERR_REMOTE_USER_TERM_CONN (0x13)"
// strings disabled
Security failed: 5E:67:02:D3:1C:DB (random) level 1 err " (6)"
Disconnected from 5E:67:02:D3:1C:DB (random), reason " (0x13)"
```

Signed-off-by: Rubin Gerritsen <rubin.gerritsen@nordicsemi.no>
2024-07-31 12:56:11 +02:00
..
src Bluetooth: Samples: Use string printing functions for error codes 2024-07-31 12:56:11 +02:00
CMakeLists.txt
prj.conf
README.rst
sample.yaml

.. _ble_peripheral_accept_list:

Bluetooth: Peripheral Accept List
#################################

Overview
********

This application demonstrates the BLE advertising accept filter list feature.
If no device is bonded to the peripheral, casual advertising will be performed.
Once a device is bonded, on subsequent boots, connection requests will only be
accepted if the central device is on the accept list. Additionally, scan response
data will only be sent to devices that are on the accept list. As a result, some
BLE central devices (such as Android smartphones) might not display the device
in the scan results if the central device is not on the accept list.

This sample also provides two BLE characteristics. To perform a write, devices need
to be bonded, while a read can be done immediately after a connection
(no bonding required).

Requirements
************

* A board with BLE support
* Second BLE device acting as a central. For example another Zephyr board or smartphone

Building and Running
********************

This sample can be found under :zephyr_file:`samples/bluetooth/peripheral_accept_list` in the
Zephyr tree.

See :ref:`bluetooth samples section <bluetooth-samples>` for details.