DFU V2 PAN Loader Example

Source code path: example/dfu_v2/bt_pan/loader

Supported Platforms

This loader does not keep its own partition table; it is compiled together with the board project of the companion PAN user application. The current PAN user-application project covers these SF32LB52X (NOR flash) boards:

• sf32lb52-lcd_n16r8_hcpu

• sf32lb52-lchspi-ulp_hcpu

• sf32lb52-nano_a128r16_hcpu

Overview

This example is the DFU V2 loader subprogram for the Bluetooth PAN channel. It pulls the new firmware over the phone-shared PAN network, writes it directly into the target partition, and reboots back into the new user application.

Usage Instructions

This loader normally does not need a separate build. The companion PAN user-application project pulls it in as a child project through AddDFU_PAN_V2(SIFLI_SDK) in its SConstruct, so building the app also produces the loader firmware. The usual flow is to build from the PAN user-application project directory; it can also be built standalone from this loader project directory.

Hardware Requirements

Before running this example, prepare:

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

• A phone that provides a PAN network.

menuconfig Configuration

Key configuration for this example (enabled by default in proj.conf):

• Macro switch: CONFIG_USING_DFU_V2

  • Description: Enable the DFU V2 middleware.

• Macro switch: CONFIG_DFU_V2_USE_DEVICE_MODE

  • Description: Run in device (target / updated side) mode.

• Macro switch: CONFIG_DFU_V2_USE_PAN_TRANSPORT

  • Description: Use PAN as the firmware transport channel.

• Macro switch: CONFIG_BLUETOOTH

  • Description: Enable Bluetooth functionality.

• Macro switch: CONFIG_CFG_PAN

  • Description: Enable the PAN profile.

• Macro switch: CONFIG_CFG_HID

  • Description: Enable the HID profile.

• Macro switch: CONFIG_BT_AUTO_CONNECT_LAST_DEVICE

  • Description: Automatically reconnect to the last connected device.

• Macro switch: CONFIG_RT_USING_LWIP

  • Description: Enable the LWIP network stack to fetch firmware over the PAN network.

• Macro switch: CONFIG_LWIP_ALTCP_TLS

  • Description: Enable LWIP ALTCP TLS support.

• Macro switch: CONFIG_PKG_USING_MBEDTLS

  • Description: Enable the mbedTLS crypto library.

• Macro switch: CONFIG_PKG_USING_WEBCLIENT

  • Description: Enable webclient to download firmware over the PAN network.

• Macro switch: CONFIG_PKG_USING_LITTLEVGL2RTT

  • Description: Enable the LVGL upgrade UI.

• Macro switch: CONFIG_LVGL_V9

  • Description: Use LVGL V9 to draw the upgrade UI.

Compilation and Flashing

Switch to the PAN user-application project directory and run the scons command to compile; building the app automatically includes this loader:

> scons --board=sf32lb52-lcd_n16r8_hcpu -j8

It can also be built standalone from this loader project directory:

> scons --board=sf32lb52-lcd_n16r8_hcpu -j8

For detailed compilation and download steps, please refer to the Quick Start Guide.

Expected Results

After the example starts:

1. The local name is set to sifli-pan, and the loader waits for the phone to connect.

2. After the phone connects and joins the PAN network, the auto-update routine execute_ota_update() is triggered: it runs a DNS check for ota.sifli.com → reads the firmware info that the user application pre-wrote at DFU_FWINFO_BASE_ADDR in flash → calls the blocking dfu_download().

3. On success it clears the firmware info in flash, the UI shows the progress, then it reboots into the new user application.

For debugging, the finsh command ota_cmd is available with subcommands: del_bond, conn_pan, download, print, clear, test_flags, test_dns.

Troubleshooting

Reference Documentation

Update History

Version	Date	Release Notes
0.0.1	06/2026	Initial version