BLE Pair Example

Source path: example/ble/pair

Supported Platforms

All platforms

Overview

This example shows how to use GAP peripheral pairing on this platform.

How to Use

This example acts as a BLE Peripheral, starts advertising on boot, and supports pairing. You can use a mobile BLE app to complete pairing and verify GATT read/write.

Procedure

1. Power on the device. It starts advertising automatically. The name format is SIFLI_APP-xx-xx-xx-xx-xx-xx.

2. Use a mobile BLE app to scan and connect.

3. After connection, send cmd_diss set_sec xx xx to trigger pairing. For example:

cmd_diss set_sec 0 2

• Parameter note: 0 is the connection index conn_idx (usually 0 for a single connection). 2 is the security level (LE_SECURITY_LEVEL_NO_MITM_BOND: bonding without MITM). After sending the command, the phone shows a pairing request.

Tap Pair. The phone asks for a PIN. Enter the PIN shown in the device log to complete pairing.

4. After connecting, use the BLE app to perform GATT read/write tests:

   • Read: returns 4 bytes (little-endian).

   • Write: supports 1 to 4 bytes. The UART log prints the new value.

Hardware Requirements

Before running this example, prepare:

• A development board supported by this example (Supported Platforms).

• A mobile phone.

menuconfig Settings

1. Enable Bluetooth (BLUETOOTH):

   • Path: Sifli middleware → Bluetooth

   • Enable: Enable bluetooth

     • Macro: CONFIG_BLUETOOTH

     • Purpose: Enables Bluetooth.

2. Enable GAP, GATT Client, BLE connection manager:

   • Path: Sifli middleware → Bluetooth → Bluetooth service → BLE service

   • Enable: Enable BLE GAP central role

     • Macro: CONFIG_BLE_GAP_CENTRAL

     • Purpose: Enables BLE CENTRAL role (scan and initiate connections).

   • Enable: Enable BLE GATT client

     • Macro: CONFIG_BLE_GATT_CLIENT

     • Purpose: Enables GATT CLIENT for service discovery, read/write, and notifications.

   • Enable: Enable BLE connection manager

     • Macro: CONFIG_BSP_BLE_CONNECTION_MANAGER

     • Purpose: Enables BLE connection management (multi-connection, pairing, connection parameter updates).

3. Enable NVDS:

   • Path: Sifli middleware → Bluetooth → Bluetooth service → Common service

   • Enable: Enable NVDS synchronous

     • Macro: CONFIG_BSP_BLE_NVDS_SYNC

     • Purpose: BLE NVDS sync access. Enable when BLE runs on HCPU; disable when BLE runs on LCPU.

Build and Flash

Switch to the example project directory and build with scons:

> scons --board=eh-lb525 -j32

Switch to the example project/build_xx directory, run uart_download.bat, and follow the prompt to select the port:

$ ./uart_download.bat

     Uart Download

please input the serial port num:5

For detailed build and download steps, refer to Quick Start.

Expected Results

1. On power-up, the UART prints receive BLE power on! and advertising starts.

2. The phone can discover and connect. The log shows Peer device(xx-xx-xx-xx-xx-xx) connected.

3. When pairing is triggered, the log prints SHOW PIN or SHOW NC, and the connection remains after pairing.

4. During GATT read/write tests, the log prints Updated app value from:xx to:xx.

Troubleshooting

References

Revision History

Version	Date	Notes
0.0.1	01/2025	Initial version