Datasheet

Transitioning between the two board types (sniffer and Bluefruit LE module) is unfortunately not a risk-free operation, and requires external
hardware, software and know-how to get right, which is why it isn't covered by our support team.
That said ... if you're determined to go down that lonely road, and you have a Segger J-Link (http://adafru.it/fYU) (which is what we use internally
for production and development), or have already erased your Bluefruit LE device, you should have a look at AdaLink (http://adafru.it/fPq), which is
the tool we use internally to flash the four files required to restore a Bluefruit LE module. (Note: recent version of AdaLink also support the cheaper
STLink/V2 (http://adafru.it/2548), though the J-Link is generally more robust if you are going to purchase a debugger for long term use.)
The mandatory Intel Hex files are available in the Bluefruit LE Firmware repo (http://adafru.it/edX). You will need to flash:
An appropriate bootloader image
An appropriate SoftDevice image
The Bluefruit LE firmware image
The matching signature file containing a CRC check so that the bootloader accepts the firmware image above (located in the same folder as
the firmware image)
The appropriate files are generally listed in the version control .xml file (http://adafru.it/fPr) in the firmware repository.
If you are trying to flash the sniffer firmware (at your own risk!), you only need to flash a single .hex file, which you can find
here (http://adafru.it/fYV). The sniffer doesn't require a SoftDevice image, and doesn't use the fail-safe bootloader -- which is why changing is a one
way and risky operation if you don't have a supported SWD debugger.
Adafruit_nF51822_Flasher
We also have an internal python tool available that sits one level higher than AdaLink (referenced above), and makes it easier to flash specific
versions of the official firmware to a Bluefruit LE module. For details, see the Adafruit_nRF51822_Flasher (http://adafru.it/fVL) repo.
Can I access BETA firmware releases?
The latest versions of the Bluefruit LE Connect applications for iOS and Android allow you to optionally update your Bluefruit LE modules with pre-
release or BETA firmware.
This functionality is primarilly provided as a debug and testing mechanism for support issues in the forum, and should only be used when trying to
identify and resolve specific issues with your modules!
Enabling BETA Releases on iOS
Make sure you have at least version 1.7.1 of Bluefruit LE Connect
Go to the Settings page
Scroll to the bottom of the Settings page until you find Bluefruit LE
Click on the Bluefruit LE icon and enable the Show beta releases switch
You should be able to see any BETA releases available in the firmware repo now when you use Bluefruit LE Connect
Enabling BETA Releases on Android
Make sure you have the latest version of Bluefruit LE Connect
Open the Bluefruit LE Connect application
Click the "..." icon in the top-right corner of the app's home screen
Select Settings
Scroll down to the Software Updates section and enable Show beta releases
You should be able to see any BETA releases available in the firmware repo now when you use Bluefruit LE Connect
Why can't I see my Bluefruit LE device after upgrading to Android 6.0?
In Android 6.0 there were some important security changes (http://adafru.it/jcU) that affect Bluetooth Low Energy devices. If location services are
unavailable (meaning the GPS is turned off) you won't be able to see Bluetooth Low Energy devices advertising either. See this
issue (http://adafru.it/jcV) for details.
Be sure to enable location services on your Android 6.0 device when using Bluefruit LE Connect or other Bluetooth Low Energy applications with
your Bluefruit LE modules.
What is the theoretical speed limit for BLE?
This depends on a variety of factors, and is determined by the capabilities of the central device (the mobile phone, etc.) as much as the peripheral.
Taking the HW limits on the nR51822 into account (max 6 packets per connection interval, and a minimum connection interval of 7.5ms) you end
up with the following theoretical limits on various mobile operating systems:
iPhone 5/6 + IOS 8.0/8.1
6 packets * 20 bytes * 1/0.030 s = 4 kB/s = 32 kbps
iPhone 5/6 + IOS 8.2/8.3
3 packets * 20 bytes * 1/0.030 s = 2 kB/s = 16 kbps
© Adafruit Industries
https://learn.adafruit.com/introducing-the-adafruit-bluefruit-le-uart-
friend
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