Datasheet

Device Recovery

Sometimes, bad things unfortunately happen. Thankfully, 99% of the time it's purely a SW

issue and the Bluefruit devices have a robust bootloader with some fail safes that can almost

always recover your device.

How to Recover a Bluefruit Board

1. Force DFU Mode at Startup

The first step is to force your board into a special bootloader mode, which will prevent any

faulty user sketches or corrupted config data from causing problems.

Connect the DFU pin to GND with a jumper cable, or if your board has a DFU button

hold the button down when adding power to your board (connecting the USB cable,

etc.)

Once the device is powered, you should see a faster DFU MODE blinky pattern that

lets you know you are in bootloader mode.

Now remove the jumper cable between DFU and GND (to prevent going into DFU

mode when you reset)

2. Update the Bluefruit Firmware

Next, update your device to the latest Bluefruit firmware using the Bluefruit LE Connect app.

We regularly fix bugs, and it's always a good idea to be on the latest release.

You can perform a firmware update in DFU mode, although the Bluefruit board may appear

as DfuTarg in the Bluefruit LE Connect app, and you will will need to select the right firmware

'family' for you board.

Because bootloader mode is a fail safe mode and has a small subset of Bluefruit's features,

we can't tell the Bluefruit LE Connect app very many details about our HW. As such, you will

need to indicate which firmware type to flash ... specifically, whether to flash the UART of SPI

based firmware. Be sure to select the right one, based on your product and the table below:

BLEFRIEND32 Firmware (UART, 32KB SRAM)

Remove the jumper cable between DFU and GND once you are in DFU mode so

that you exit it during the next reset!