doc: samples: Update bluetooth/central README

Add relevant details to README file of samples/bluetooth/central

Signed-off-by: Manojkumar Konisetty <[email protected]>

Author: manoj-aerlync

samples/bluetooth/central/README.rst

@@ -2,24 +2,60 @@
    :name: Central
    :relevant-api: bluetooth
 
-   Implement basic Bluetooth LE Central role functionality (scanning and connecting).
+   Implement basic Bluetooth LE Central role functionality
+   (scanning and connecting).
 
 Overview
 ********
 
-Application demonstrating very basic Bluetooth LE Central role functionality by scanning
-for other Bluetooth LE devices and establishing a connection to the first one with a
-strong enough signal.
+This application demonstrates basic Bluetooth LE Central role functionality
+by scanning for other Bluetooth LE devices and establishing a connection
+to the first one with a strong enough signal.
+
+Core features
+*************
+
+Scanning for devices
+====================
+
+The application initiates a passive scan to detect nearby Bluetooth LE devices.
+It specifically looks for devices that have a signal strength greater
+than -50dBm. This threshold helps the app filter out weaker signals,
+ensuring it only interacts with devices that are within a reasonable RSSI
+range for communication.
+
+Connection handling
+===================
+
+1. The Central scans for Peripheral devices and if it finds a Peripheral
+   which has a signal strength higher than -50dBm, an attempt to establish
+   LE connection is made.
+2. If the connection is successful, the Central initiates disconnect to
+   the Peripheral and then restarts the scan.
+3. If there are no connections, the Central keeps scanning continuously.
+
+The sample is used to demonstrate the Central mode capabilities of Bluetooth LE and
+hence a disconnect is issued right immediately after establishing a connection with
+a Peripheral, allowing the Central to resume scanning for other devices.
 
 Requirements
 ************
 
 * BlueZ running on the host, or
 * A board with Bluetooth LE support
 
-Building and Running
+Building and running
 ********************
-This sample can be found under :zephyr_file:`samples/bluetooth/central` in the
-Zephyr tree.
 
-See :zephyr:code-sample-category:`bluetooth` samples for details.
+Build and flash the sample as follows, replacing board_name with your
+target board:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/bluetooth/central
+   :board: board_name
+   :goals: build flash
+   :compact:
+
+To test Central's scanning functionality, either flash the :zephyr:code-sample:`ble_peripheral`
+sample on a second compatible board or use an off-the-shelf Bluetooth LE enabled
+device that can act as a Peripheral (eg. smartphone, smartwatch, etc.).