github.com/fako1024/gatt (go): Package gatt provides a Bluetooth Low Energy gatt implementation.  Gatt (Generic Attribute Profile) is the protocol used to write BLE peripherals (servers) and centrals (clients).  This package is a work in progress. The API will change.  As a peripheral, you can create services, characteristics, and descriptors, advertise, accept connections, and handle requests. As a central, you can scan, connect, discover services, and make requests.  gatt supports both Linux and OS X.  On Linux: To gain complete and exclusive control of the HCI device, gatt uses HCI_CHANNEL_USER (introduced in Linux v3.14) instead of HCI_CHANNEL_RAW. Those who must use an older kernel may patch in these relevant commits from Marcel Holtmann:  Note that because gatt uses HCI_CHANNEL_USER, once gatt has opened the device no other program may access it.  Before starting a gatt program, make sure that your BLE device is down:  If you have BlueZ 5.14+ (or aren't sure), stop the built-in bluetooth server, which interferes with gatt, e.g.:  Because gatt programs administer network devices, they must either be run as root, or be granted appropriate capabilities:  USAGE  See the server.go, discoverer.go, and explorer.go in the examples/ directory for writing server or client programs that run on Linux and OS X.  Users, especially on Linux platforms, seeking finer-grained control over the devices can see the examples/server_lnx.go for the usage of Option, which are platform specific.  See the rest of the docs for other options and finer-grained control.  Note that some BLE central devices, particularly iOS, may aggressively cache results from previous connections. If you change your services or characteristics, you may need to reboot the other device to pick up the changes. This is a common source of confusion and apparent bugs. For an OS X central, see http://stackoverflow.com/questions/20553957.  gatt started life as a port of bleno, to which it is indebted: https://github.com/sandeepmistry/bleno. If you are having problems with gatt, particularly around installation, issues filed with bleno might also be helpful references.  To try out your GATT server, it is useful to experiment with a generic BLE client. LightBlue is a good choice. It is available free for both iOS and OS X.
Keywords: bluetooth|bluetooth-low-energy|gatt|gatt-client|gatt-service