RedBear Labs has built a fantastic small profile, low cost, Bluetooth Low Energy board which is perfect for prototyping or hobby IoT projects: http://redbearlab.com/blemini/
From their website:
You can now incorporate Bluetooth 4.0 Low Energy (BLE) technology easily in your project with our BLE Mini. BLE Mini requires only a serial port for communication so it supports all major development platforms that have UART interface including Arduino, Raspberry Pi, Netduino, BeagleBone etc. In addition, we provide you with access to all Ti's CC2540 I/O pins and the ability to upload firmware via USB, making the BLE Mini an ideal development/prototyping board for your BLE project/accessory/Appcessory.
To get the most out of the BLE Mini you’re probably going to want to install the latest firmware. It turns out it’s a fairly straight forward process, but there are a few things worth noting.
1st – Download the latest Firmware
You can download the latest firmware from GitHub here: https://github.com/RedBearLab/Biscuit/tree/master/release
For the BLE Mini we’re looking for a file labelled “Biscuit-UART-xxxxxxxx.bin”. At the time of writing it’s “Biscuit-UART_20140409.bin” which was built in April, 2014.
2nd – Find a Windows 7 PC
Unfortunately the firmware update cannot be updated from Windows 8/8.1. In the RedBear forums it states it should work from a Windows 7 Virtual Machine. However, I tried it from within a VMWare Player Windows 7 VM, and although I was able to reach the BLE Mini, I wasn’t able to update the firmware.
Fortunately I still have my trusty little Acer 1810T running Windows 7, which I used to update the firmware.
3rd – Connect the BLE Mini to the Win7 PC
There’s one small black button on the top the BLE Mini, close to the Micro USB port. Hold this down while connecting your Mini via a regular USB Micro cable.
The first time you connect the BLE Mini this way, Windows will probably need to search for drivers. Once you see the “Installing device driver software” popup in the system tray, leave the BLE Mini connected but you can let go of the button.
Once it’s installed you’re ready to move on, and you should see a new disk in the file explorer with a capacity of 240 KB.
4th – Update the Firmware
Now it’s simply a matter of removing the old .bin file and copying in the new one. You may want to back up the old version “just in case”.
Just be warned, when I updated my two BLE Minis, they both rebooted after every file operation. And I needed to repeat the process of holding down the button and reconnecting the BLE Mini to continue. Otherwise it was a smooth and simple process.
Again just replace the old .bin file with the new one, no need to rename the file, etc.
5th – Test it Out
Disconnect the BLE Mini and then reconnect it to a power source (without holding the button). If the green light comes on you should be all set. RedBear also has free iOS and Android BLE Controller Apps you can use to test functionality.
The behaviour of the new firmware seems to be basically the same, with improved stability and connectivity, but the broadcast name has been changed from “Biscuit” to “BLE Mini”. All of the services and characteristic GUIDs should be the same.
Now If something goes horribly wrong, there are instructions for resetting and reformatting the BLE Mini in the RedBear Labs forums:
If you’re not sure where to go next, I have some sample code to connect to the BLE Mini from Windows Phone 8.1 here: https://github.com/adrianstevens/WP8_RedBear_BLEMini
And here’s an article introducing BLE communication between a similar BLE board from Seeed Studios using Android: https://software.intel.com/en-us/articles/connecting-to-intel-edison-from-android-with-bluetooth-le-ble?language=de
And finally, when you’re ready for a bigger task, check out the Monkey Robotics project. It has a ton of great code including a walkthrough to build a BLE controlled car using the RedBear BLE Mini, and connecting from a Xamarin Forms project: https://github.com/xamarin/Monkey.Robotics