Datasheet

Flashing the Bootloader

All Bluefruit nRF52 Feather boards and Bluefruit nRF52 modules ship with the serial bootloader pre-flashed, so this

page is normally not required when setting your device and system up.

The information provided here is only intended for for rare cases where you may want or need to reflash the

bootloader yourself, and have access to the HW required to do so.

1. Updating the Bootloader with the DFU Bootloader

The bootloader can be used to update itself using the latest version of the Adafruit Bluefruit nRF52 Board Support

Package. This update process uses the same serial connection as you would use when updating the user sketch.

Select Tools > Board > Adafruit Bluefruit Feather52

Select Tools > Programmer > Bootloader DFU for Bluefruit nRF52

Select Tools > Burn Bootloader

2. Updating the Bootloader with a Segger J-Link and Arduino IDE

To burn the bootloader from within the Arduino IDE using a Segger J-Link, you will need the following tools installed on

your system and available in the system path:

JLink Drivers and Tools

Download and install the JLink Software and Documentation Pack (https://adafru.it/vaI) from Segger, which will also

install a set of command line tools.

Burning the Bootloader from the Arduino IDE

Once the tools above have been installed and added to your system path, from the Arduino IDE:

Select `Tools > Board > Adafruit Bluefruit Feather52`

Select `Tools > Programmer > J-Link for Feather52`

Select `Tools > Burn Bootloader` with the board and J-Link connected

The appropriate Programmer target and Burn Bootloader button can be seen below:

All Adafruit nRF52 boards chip with the bootloader pre-flashed. This page is provided for information

purposes only!

You will need a Segger J-Link to flash the bootloader to the nRF52832/nRF52840 SoC!