Neptor KB300BF-WH Foldable Bluetooth Keyboard Review @ HiTech Legion
 

EagleTech's Neptor KB300BF-WH uses the agility of Bluetooth to let you do some real typing on the go. The Neptor KB300BF uses the HID protocol to maximize compatibility with Bluetooth devices, such as tablets and phones. There are even adapters you can get that will let you use this keyboard with microcontrollers, like Arduino or the Raspberry Pi. While it only has 83 keys, they are the ones you need most and many have alternate functions to make up for those that are missing. It also sports an internal rechargeable Lithium-Ion battery and a 10-meter range (about 30 ft).

http://www.hitechlegion.com/reviews/.../36167-kb300bf