The Bootloader/DFU with SoftDevice update example shows how a SoftDevice, bootloader, and pplication can be updated on aN nRF51822 chip. The new SoftDevice, Bootloader, or pplication image can be transfered Over-The-Air (OTA) using the Nordic BLE DFU Service.

The SDK provides support for OTA interface in form of BLE.

The documentation for the Bootloader/DFU with SoftDevice update example is structured as:

Section	Description
Introduction to Bootloader/DFU	Introduction to the Bootloader/DFU with SoftDevice update example project
Bootloader/DFU Architecture	Architectual view of the Bootloader/DFU Solution
Application support for DFU Service	Including DFU Service in application to support entering Bootloader/DFU mode through application
Init packet handling	Description of the DFU Init packet for safety checking of software images transfered
Bootloader/DFU Keil Project	Description of the Keil project, compiling Bootloader/DFU, and software flash download (nrfjprog)
DFU BLE Transport Layer	DFU BLE Transport Layer description
Flash Memory Layout	Detailed description of the flash memory layout for SoftDevice, application, and bootloader/DFU
Bootloader/DFU API	API description for modules specific for the Bootloader/DFU Example