zephyr/samples/bluetooth/direct_adv
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_direct_adv:

Bluetooth: Direct Advertising
#############################

Overview
********

Application demonstrating the BLE Direct Advertising capability. If no device is bonded
to the peripheral, casual advertising will be performed. Once bonded, on every subsequent
boot direct advertising to the bonded central will be performed. Additionally this sample
provides two BLE characteristics. To perform write, devices need to be bonded, while read
can be done just after connection (no bonding required).

Please note that direct advertising towards iOS based devices is not allowed.
For more information about designing BLE devices for Apple products refer to
"Accessory Design Guidelines for Apple Devices".

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

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

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

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

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